JP3279457B2 - Control device for permanent magnet synchronous motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet for applying a d-axis current value to a synchronous motor used in an electric vehicle or the like so as to improve the efficiency of the synchronous motor when performing field-weakening control or maximum efficiency control on the synchronous motor. The present invention relates to a control device for a synchronous motor.

[0002]

2. Description of the Related Art The Institute of Electrical Engineers of Japan, IEA-92-30 (Reference 1), calculates a field current command value id ^* as shown in the following equation 1 and performs field weakening control. Is shown.

[0003]

(Equation 1)

Note that ωbase indicates a base rotation speed, and ωmax
Indicates the maximum rotation speed, and idm indicates the d-axis current at the maximum rotation speed ωmax.

[0005] In the 1991 IEEJ National Conference on Industrial Applied Technology, No. 74, pp. 310-315 (Reference 2), the field current command value id ^* is set to the target rotation speed, d-axis winding reactance, q It shows that the field-weakening control is performed by calculating using the shaft winding reactance, the stator winding resistance, the no-load induced voltage at a unit speed, and the like.

In JP-A-57-196896 or JP-A-62-7396, a controller detects an error (degree of realization) between a motor torque or current actually measured in real time and a command value. The error is fed back.
This allows real-time id
Current can be provided to the motor.

[0007]

In the conventional methods described in Documents 1 and 2, in field-weakening control in a high-speed rotation region, a field current id is expressed by an equation according to a target rotation speed ω.
Is given.

However, in an actual motor, a constant of the motor changes due to a change in resistance value or a change with time due to an operation state (the electric resistance of the motor increases by about 30% when the temperature rises by about 70 degrees near normal temperature). Therefore, the id calculated by the operation formula of the conventional method is not always the optimum id.

Therefore, when it is desired to output a high torque at a high rotation speed, it is necessary to give a large id current in anticipation of the characteristic change (for example, an inductance of 4 mH, a stator frequency of 133 Hz, and a back electromotive voltage at an applied voltage of 80 V). Is required to realize 80V and torque current iq1A.
Is 1.95 A when the resistance is 1 Ω and 2.6 when the resistance is 1.3 Ω.
3A).

[0010] Therefore, there is a problem that the copper loss increases by the amount of id given more and the efficiency becomes worse.

On the other hand, Japanese Patent Application Laid-Open Nos. 57-196896 and 62-7396 disclose that id is obtained and supplied by feedback, as shown below.
There is a problem in that the design method or the control operation is insufficient and it is difficult to realize a feasible stable operation.

1. When the characteristic fluctuation is very large, it is not easy to respond to the characteristic fluctuation.

2. No mention is made of a method for improving responsiveness.

3. Optimal d-axis current cannot be given in power running and regeneration of the motor.

[0015] 4. No mention is made of efficiency improvement other than the method of finding id by feedback control.

5. For example, when the voltage of the battery decreases and the terminal voltage supplied to the synchronous motor decreases, the d-axis current flows too much with respect to the total current, resulting in poor efficiency.

6. With a single reference value, it is impossible to achieve both efficiency maximization and torque maximization.

7. The d-axis and q-axis currents cannot be controlled separately, and one response is sacrificed.

8. It is not clear how to deal with circuit or system errors.

[0020]

SUMMARY OF THE INVENTION A control device for a permanent magnet synchronous motor according to the present invention uses a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Current command means for outputting a calculated current value of each phase of the stator, input applying means for supplying current to each phase based on the current value of each phase, and the input applying means applying current to each phase. Further, a saturation output means for generating a saturation indicating a supply ratio, a reference output means for outputting a reference value of the saturation, and a determination value for calculating a determination value obtained by subtracting the reference value of the saturation from the saturation. Output means, if the judgment value is positive, advance the current phase, increase the command value of the d-axis current so that the judgment value becomes zero, and if the judgment value is negative,
When the command value of the d-axis current is reduced and the command value of the reduced d-axis current is reduced beyond a set minimum value,
There are provided d-axis current command means for holding the command value of the axis current at the minimum value, and q-axis current command means for giving the command value of the q-axis current, thereby achieving the above object.

[0021] The saturation output means may generate the saturation based on a difference between at least a phase current command value of the stator and a value of a phase current of the permanent magnet synchronous motor.

[0022] The saturation output means may generate the saturation based on a value obtained by integrating a difference between a current of at least one phase and a current command value of a phase corresponding to the at least one phase.

[0023] The saturation output means may include an integrator for integrating the difference, and may include an element which can be changed to the control device to adjust a rate at which the integrator integrates.

When the judgment value is positive, the d-axis current command means increases the command value of the d-axis current, and when the command value of the increased d-axis current is larger than a preset maximum value. The d-axis current command means sets the command value of the d-axis current to the preset maximum value, and if the judgment value is negative, the d-axis current command means sets the command value of the d-axis current. When the rotation speed of the permanent magnet synchronous motor is equal to or less than a predetermined rotation speed, the d-axis current command means may set the command value of the d-axis current to a predetermined minimum value. .

The saturation output means generates the saturation based on a value obtained by integrating the difference between the command value of the q-axis current and the value of the q-axis current flowing through the stator of the permanent magnet synchronous motor. You may.

The reference output means may change the reference value based on at least one of the current command value of each phase and the rotation speed of the permanent magnet synchronous motor.

The saturation output means may further include an integrator for integrating the difference, and the control device may have a changeable element for adjusting a rate at which the integrator integrates. Is also good.

The saturation degree output means calculates a difference between a torque command value calculated based on at least one current value command value and an actual torque of the permanent magnet synchronous motor.
The degree of saturation may be generated.

The saturation degree output means calculates a difference between a value obtained by integrating at least one phase current command value and a value obtained by integrating and calculating the detected value of the phase current flowing through the stator of the permanent magnet synchronous motor. The saturation may be generated based on the saturation.

When the judgment value is positive, the d-axis current command means increases the command value of the d-axis current, and when the command value of the increased d-axis current is larger than a preset maximum value. The d-axis current command means sets the command value of the d-axis current to the preset maximum value, and if the judgment value is negative, the d-axis current command means sets the command value of the d-axis current. When the reduced d-axis current command value is smaller than a preset d-axis minimum value, the d-axis current command means changes the d-axis current command value to the preset minimum value. May be set.

The d-axis current command means increases the command value of the d-axis current when the judgment value is positive, and decreases the command value of the d-axis current when the judgment value is negative. When the command value of the reduced d-axis current is smaller than a preset d-axis minimum value, the command value of the d-axis current is set to the preset minimum value; Is based on a value obtained by vector-subtracting the command value of the d-axis current from a preset maximum value of a combined current value obtained by vector-adding the command value of the d-axis current and the command value of the q-axis current, and the speed. A smaller value among the created q-axis current command values may be used as the q-axis current command value.

The control device includes a speed detecting means for detecting a rotation speed of the permanent magnet synchronous motor, and a command value of the d-axis current is a value within a certain range for a certain period, and the rotation speed is A change timing output means for forcibly outputting a timing for changing the command value of the d-axis current when the value is within a certain range; and a command value for the d-axis current and the q A d-axis current changing unit that holds a synthesized current command value obtained by synthesizing the d-axis current command value with the d-axis current command value, and that changes the d-axis current command value; After changing the command value,
When the rotation speed is higher than the rotation speed before changing the command value of the d-axis current, an operation using the d-axis current command value after changing the command value of the d-axis current; and When decreasing, the operation using the d-axis current command value before changing the d-axis current command value is repeatedly performed for a period permitted by the change timing output unit, and the d-axis current command value is changed. D-axis current updating means for updating, wherein the d-axis current updating means changes the command value of the d-axis current, and when the determination value is positive, the d-axis current updating means
The axis current updating means changes the reference value of the reference output means to a newly calculated reference value, and if the judgment value is negative, the d-axis current updating means sends the d-axis current to the d-axis current command means. Based on a value output from the d-axis current updating means, a preset minimum value of the d-axis current or a coefficient of an equation for calculating a command value of the d-axis current may be set.

When the command value of the q-axis current greatly changes to a value not less than a preset value, a current initial value output means for outputting an initial command value of the d-axis current obtained from the q-axis current command value is further provided. May be provided.

The control device further includes change rate output means for determining and outputting a change rate of the command value of the d-axis current, wherein the change rate output means determines a predetermined constant change rate or the judgment value. A value or a change rate calculated from the command value of the d-axis current, and the d-axis current command means increases the command value of the d-axis current based on the change rate when the judgment value is positive. When the command value of the d-axis current increases beyond a preset maximum value,
The command value of the d-axis current is held at the preset maximum value, and when the judgment value is negative, the command value of the d-axis current is decreased based on the change rate, and the command of the d-axis current is When the value decreases beyond a preset minimum value, the command value of the d-axis current may be held at the preset minimum value.

When the judgment value is positive, the change ratio is
The change rate may be larger than the change rate when the judgment value is negative.

[0036]

[0037] The control device further includes a powering regeneration judging means for judging whether the operation of the permanent magnet synchronous motor is in a powering state or a regenerative state. The rate at which the command value of the d-axis current is changed may be determined based on the determined state.

[0038] The ratio of changing the command value of the d-axis current in the power running state may be smaller than the ratio of changing the command value of the d-axis current in the regenerative state.

The reference output means may change a reference value based on the output of the power running regeneration judging means.

When the judgment value is positive, the d-axis current command means increases the command value of the d-axis current based on the rate of change, and exceeds the set maximum value. When the value increases, the command value of the d-axis current is held at the set maximum value, and when the judgment value is negative, the command value of the d-axis current is decreased based on the change rate, and the setting is performed. When the command value of the d-axis current decreases beyond the minimum value, the command value of the d-axis current is held at the minimum value, and the powering / regeneration judging means detects a change in the operating state of powering or regeneration. A signal indicating the d-axis current may be changed from a previous d-axis current command value based on at least one of the rotation speed of the permanent magnet synchronous motor and the q-axis current command value. Good.

When the allowable value of the braking torque of the permanent magnet synchronous motor is small, the d-axis current command means generates reluctance torque in accordance with the decrease of the torque command value.
In order to suppress a decrease in the shaft current, the command value of the d-axis current may not be rapidly reduced.

Another control device for a permanent magnet synchronous motor according to the present invention comprises a stator which is obtained from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Current command means for outputting a command value of each phase current, input application means for supplying a current to each phase based on each phase current command value, whether the operation of the permanent magnet synchronous motor is power running,
Alternatively, the power running regeneration judging means for judging whether the operation of the permanent magnet synchronous motor is regenerative, and the power running regeneration judging means judging the state to be regenerative, and the number of rotations of the permanent magnet synchronous motor and When the torque does not belong to the field-weakening region, the d is set so that the permanent magnet synchronous motor generates reluctance torque of zero or more power running.
D-axis current command means for outputting a command value of axis current;
Q-axis current command means for giving a command value of the axis current is provided, whereby the object is achieved.

Still another permanent magnet synchronous motor control device according to the present invention is calculated from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Current command means for outputting a current command value for each phase of the stator, input application means for supplying a current to each phase based on the current command value for each phase, and whether the operation of the permanent magnet synchronous motor is power running, or Powering regeneration determining means for determining whether the operation of the permanent magnet synchronous motor is regenerative; and a d-axis providing a command value of the d-axis current when the powering regeneration determining means determines that the state is regenerative. Current command means, and q-axis current command means for decreasing the command value of the q-axis current in accordance with an increase in the command value of the d-axis current by the amount of reluctance torque when the d-axis current command is not zero. And the The above-mentioned object can be achieved by the.

Still another permanent magnet synchronous motor control device according to the present invention is calculated from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Current command means for outputting a current command value for each phase of the stator; input application means for supplying current to each phase based on the current command value for each phase; and the input application means can further supply current to each phase. A saturation output unit that generates a saturation indicating a ratio, a reference output unit that outputs a reference value of the saturation,
A judgment value output unit that outputs a judgment value obtained by subtracting the reference value of the saturation degree from the saturation degree, a voltage measurement unit that measures a voltage applied to the inverter, and outputs a measured voltage value, and the measured voltage A d-axis current maximum value output means for outputting a maximum value of the command value of the d-axis current based on the value, and when the judgment value is positive, increasing the command value of the d-axis current, When the command value increases beyond the d-axis current maximum value, the command value of the d-axis current is held at the d-axis current maximum value, and when the judgment value is negative, the command value of the d-axis current is increased. A d-axis current command means for holding the command value of the d-axis current at the minimum value when the command value of the reduced d-axis current decreases beyond a set minimum value; Q-axis current command means for giving a command value,
Thereby, the above object is achieved.

The d-axis current maximum value output means may decrease the maximum value of the command value of the d-axis current if the measured voltage value decreases.

Another control device for a permanent magnet synchronous motor according to the present invention is a fixed motor which is calculated from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. The current command means for outputting each phase current command value of the child, the input application means for supplying current to each phase based on each phase current command value, and the voltage applied to the permanent magnet synchronous motor were measured and measured. Voltage measuring means for outputting a voltage value; d-axis current commanding means for decreasing the maximum value of the d-axis current command value when the measured voltage value decreases; q for giving the q-axis current command value; And a shaft current commanding means, whereby the above object is achieved.

Still another permanent magnet synchronous motor control device according to the present invention is calculated from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Current command means for outputting a command value of each phase current of the stator; input application means for supplying current to each phase based on the phase current command value; and the input application means further supplying current to each phase. A degree-of-saturation output means for generating a degree of saturation indicating a possible ratio; an operation state determining means for outputting one of the operation states of an efficiency-oriented operation state and a torque-oriented operation state; Reference value output means for outputting a judgment value obtained by subtracting the reference value of the degree of saturation from the degree of saturation;
When the command value of the axis current is positive, the d-axis current command means for advancing the current phase and increasing the command value of the d-axis current so that the judgment value becomes zero, And q-axis current command means for giving a command value, whereby the object is achieved.

[0048] The reference value when the operating condition determining means outputs importance on efficiency may be larger than the reference value when the operating condition determining means outputs importance on torque.

When at least one of the number of revolutions and the current of the permanent magnet synchronous motor exceeds a preset value, the reference output means determines that the operating condition determining means attaches importance to the torque. A reference value smaller than the reference value in the case may be output.

[0050]

Still another permanent magnet synchronous motor control device according to the present invention is calculated from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Current command means for outputting a current command value for each phase of the stator; input application means for supplying current to each phase based on the current command value for each phase; and the input application means can further supply current to each phase. A saturation output unit that generates a saturation indicating a ratio, a reference output unit that outputs a reference value of the saturation,
Reference output means for outputting a reference value, d-axis reference output means for outputting a d-axis reference value according to the saturation, and q-axis reference output means for outputting a q-axis reference value according to the saturation. D-axis determination value output means for outputting a d-axis determination value based on a value obtained by subtracting the d-axis reference value from the saturation, and subtracting the q-axis reference value from the saturation processing value A q-axis determination value output unit that outputs a q-axis determination value based on the obtained value, and when the d-axis determination value is positive, increases the command value of the d-axis current and increases the increased d-axis current. When the command value of the d-axis current exceeds the set maximum value, the command value of the d-axis current is held at the set maximum value, and when the d-axis determination value is negative, the command of the d-axis current is When the command value of the decreased d-axis current decreases beyond a set minimum value, D-axis current command means for holding the command value of the axis current at the set minimum value, q-axis current command means for giving the command value of the q-axis current, the q-axis determination value is positive, and When the command value of the d-axis current is the set maximum value, the command value of the q-axis current commanded by the q-axis current command means is reduced, and the command value of the reduced q-axis current is changed to the q-axis current. A change command value, the q-axis determination value is negative, the d-axis current command value is the set maximum value, and the q-axis current change command value is commanded by the q-axis current command means. Q-axis current command changing means for increasing the command value of the q-axis current when the command value of the q-axis current is equal to or less than the command value of the q-axis current.

The d-axis reference value output from the d-axis reference output means may be smaller than the q-axis reference value output from the q-axis reference output means.

Still another permanent magnet synchronous motor control device according to the present invention is calculated from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Current command means for outputting a current command value for each phase of the stator; input application means for supplying current to each phase based on the current command value for each phase; and the input application means can further supply current to each phase. A degree-of-saturation output means for generating a degree of saturation, an operation-state determining means for outputting one of the efficiency-oriented operation states and a torque-oriented operation state, and a saturation degree reference value for the operation state. Reference output means for outputting a judgment value obtained by subtracting the reference value of the saturation from the saturation, and a judgment value output means for outputting a judgment value when the judgment value is positive. Increase the d-axis current command so that A first d-axis current commanding means for performing the operation, an abnormality detecting means for detecting an abnormality in a circuit or an operation, and a second d-axis current for obtaining a command value of the d-axis current based on a preset table or arithmetic expression Command means, q-axis current command means for giving a command value of the q-axis current, and the d-axis output from the first d-axis current command means when the abnormality detecting means does not detect an abnormality in a circuit or operation. A d-axis current selection means for selecting a command value and selecting the d-axis command value output from the second d-axis current command means when the abnormality detection means detects a circuit or operation abnormality. Thus, the above object is achieved.

[0054]

The judgment value output means creates a judgment value for increasing or decreasing id in real time based on the saturation of the inverter.
The d-axis current command means increases the command value of the d-axis current based on the judgment value when the judgment value is positive, and increases the command value of the increased d-axis current beyond the set maximum value. Is kept at the maximum value. If the judgment value is negative, the value is held at the minimum value when the value exceeds the preset d-axis minimum value or decreases or when the rotational speed falls below the preset rotational speed set value. As described above, the id current is obtained by the feedback integration control operation, and conditions for stably operating the motor, such as setting the number of rotations to enter the field weakening, are provided. As a result, an optimum id current in terms of efficiency can be stably provided in real time according to the current state of the motor. This makes it possible to provide a highly efficient permanent magnet synchronous motor control device.

[0055]

The control device of the Embodiment] The first embodiment first embodiment of a permanent magnet synchronous motor of the present invention (hereinafter abbreviated as synchronous motor) will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the control device according to the first embodiment of the present invention.

The control device of the first embodiment comprises a saturation output means 104, a judgment value output means 106, and a reference output means 1
08, a d-axis current command unit 110, a q-axis current command unit 130, a current command unit 136, and an input application unit 138.

Note that this control device is a synchronous motor 100
May be further provided.

Next, the field weakening control will be briefly described with reference to Equation 2 and FIG.

The basic formula (Equation 2) of the synchronous motor 100 is known.

[0061]

(Equation 2)

V denotes a terminal voltage supplied to the motor, ω denotes an angular velocity, R denotes a stator winding resistance per phase, ψ denotes a no-load induced voltage at a unit speed,
L _d, L _q are d-axis indicates the respective phase inductance of the q-axis, i _d represents the direct axis stator current (d-axis current), i _q is shown on the horizontal axis stator current (q-axis current) I have.

In FIG. 2, the dq coordinates indicate rotational coordinates. _id and _iq indicate the DC amount of the d-axis current and the DC amount of the q-axis current, respectively.

The operation differs between the case where the operation state of the synchronous motor 100 is power running and the case where the operation state of the synchronous motor 100 is regenerative. Here, the power running is a state in which the synchronous motor 100 is generating a mechanical output, and is a state in which electric power is input from a power supply. When the battery is used, the battery is being discharged. Regeneration is a state in which the electric motor is converting mechanical energy into electric energy, and is a state in which electric power is being input to the power supply. When a battery is used, the battery is being charged.

When the synchronous motor 100 is running, as shown in the vector diagram of field weakening control (FIG. 2A), when the rotational speed ω of the synchronous motor 100 is increased, the induced voltage ω 電 圧 increases. The induced voltage ωψ, R · i _q and ω · L _q · i _q
When the voltage value v obtained by vector addition reaches the voltage limit circle, the synchronous motor 100 can increase the rotation speed to the rotation speed ω of the synchronous motor 100 when the voltage value v reaches the voltage limit circle or more. Disappears.

When the power source is a battery or the like,
Due to the deterioration of the battery, the terminal voltage and the current value of the battery change. However, for simplicity here,
It is assumed that the terminal voltage of the battery (the radius of the voltage limiting circle) is constant.

Next, consider increasing the rotational speed of the synchronous motor 100. As shown in FIG. 2 (b), by passing an i _d to the synchronous motor 100, the direction of the voltage ω · L _d · i _d back to the voltage limit circle generated. This allows
A voltage margin for increasing the rotation speed occurs in the synchronous motor 100 (FIG. 2B). When the rotation speed of the synchronous motor 100 is constant, the synchronous motor 1 is increased by the generated voltage margin.
00, a torque current for generating a torque can be caused to flow, and the synchronous motor 100 can further generate a torque (FIG. 2C). Here, _id > 0 is defined in a direction to advance the current phase. As described above, the synchronous motor 10
Control in which a d-axis current flows through 0 to generate a voltage margin is called field weakening control. One example of such field weakening control is disclosed in Japanese Patent Application Laid-Open No. 62-7396.

[0068] Incidentally, d-axis current i _d for generating the voltage margin may be minimum required current to return to the terminal voltage supplied to the motor voltage within limit circle. Given a required minimum or more d-axis current i _d to the synchronous motor 100, the copper loss is increased, the efficiency of the synchronous motor 100 is deteriorated. This is because the non-salient pole machine (general motor) shown in FIG.
This is because no torque is generated even when the shaft current is applied.

[0069] always efficient control by passing a minimal i _d in the case of non-salient machine can be realized. In the case of regeneration, it can be explained in the same way as power running.

FIG. 6 (b) shows a reverse salient pole machine. In passing the i _d in the opposite salient pole machine or salient pole machine, since the reluctance torque will be described later occurs, is better to properly supply the better the efficiency of the synchronous motor 100 in accordance with i _d to L _d and L _q .

Next, the saturation of the inverter will be described with reference to FIGS. 3, 4, and 5. FIG.

[0072] 120 degrees out of phase different three-phase current command values ^{_{(i U * (t),}} i V * (t), i W * (t)) , the current d-axis current command and the q-axis current using a command, when represented by the following formula (hereinafter, it is not necessary to particularly point that AC value is a value that varies for the time, such as omitted (t). the ^* is a command value Is shown).

[0073] i _U ^* (t) = over ^{_{(2/3) 1/2 {i d *}} · cosωt + i q * · sinωt} i V * (t) = over (2/3) ^1/2 {i _d ^* · cos (ωt-2π / 3 ) + i q * · sin (ωt-2π / 3)} i W * (t) = over ^{_{(2/3) 1/2 {i d *}} · cos (ωt + 2π / 3) + i _q ^* · sin (ωt + 2π / 3)｝ The synchronous motor 100 is connected via a pair of terminals of the control device.
Currents flowing through the stators of (i _U (t), i _V (t),
i _W (t)) is detected by the current detecting means 102. The detected currents (i _U (t), i _V (t), i
_W (t)) is output to the saturation output means 104. The saturation output means 104 has a proportional integrator shown in FIG. One end of the proportional integrator has a current command value (i
^{_{U * (t), i V}} * (t), i W * (t)) is input to the other end of the proportional integrator, the detected current (i _U (t), i
_V (t) and i _W (t)) are input. Proportional integrator, the current command value ^{_{(i U * (t),}} i V * (t), i W * (t)) and the detected current _{(i U (t), i} V (t), i W (T)) is proportionally integrated, and the PWM current errors (e _U (t), e _V
(T), e _W (t)).

FIG. 3B shows a U-phase current command value i _U ^* (t) and a U-phase current i _U (t) when an inverter described later is saturated.

FIG. 3C shows the U-phase current command value i _U ^* (t) and the U-phase current i _U (t) when the inverter is not saturated.

When the inverter is saturated, even if the current command means 136 outputs a current command signal, the inverter cannot generate the commanded current, and a pair of terminals of the control device Commanded current is not supplied.

The case where the inverter is saturated will be considered from the switching of the inverter. FIG. 4 shows an example of the inverter included in the input applying unit 138. The inverter includes semiconductor switches Q1 to Q6, a diode D
1 to D6, a base drive circuit 140 for controlling ON / OFF of the semiconductor switches Q1 to Q6, and a triangular carrier generation circuit 142.

The base drive circuit 140 includes a U-phase P
WM current error e _U (t), V-phase PWM current error e _V
(T) and the triangular carrier generated by the triangular carrier generation circuit 142 are input. The base drive circuit 140 turns on and off the semiconductor switches Q1 to Q6 of each phase of the inverter in accordance with the pulse width modulation signal obtained by comparing each PWM current error with the carrier signal. For example, U phase P
If the WM current error e _U (t) is larger than the triangular carrier, the base drive circuit 140
Is turned on, and the semiconductor switch Q4 is turned off. When the U-phase PWM current error e _U (t) is smaller than the triangular carrier, the base drive circuit 140
4 is turned on, and the semiconductor switch Q1 is turned off. The same operation is performed for the other phases.

The inverter has a U-phase PWM current error e _U (t) and a V-phase PWM current error e _V (t).
Are used to generate the currents (i _U (t), i _V (t), i _W (t)) supplied to the stator of the synchronous motor 100, but the U-phase PWM current error, V Phase PWM current error of one phase and one phase PWM current error of W phase PWM current error
The currents (i _U (t), i _V (t),
i _W (t)) may be generated. Further, any two sets of phases are selected from the three phases, and the currents (i _U (t), i _V (t), i) are selected using the selected two sets of PWM current errors.
_W (t)) may be generated. Furthermore, the three-phase P
The above current (i _U (t),
i _V (t), i _W (t)) may be generated.

FIG. 5 shows the PWM current error signal and the operation of the semiconductor switches Q1 and Q4, respectively, when the inverter is saturated and when the inverter is not saturated.

If the on-off is offset every half cycle, the current cannot flow any more even if the switching is performed sufficiently to flow the current commanded to the stator of the synchronous motor 100. The saturation of the inverter may be defined by the magnitude of the PWM current error. For example, when the PWM current error is large, the saturation of the inverter is also large, and when the PWM current error is small, the saturation of the inverter is also small.

In order to reduce the saturation of the inverter,
As described below, id can be caused to flow through the stator of the synchronous motor 100 to perform a field weakening that advances the current phase.

One of the three-phase currents (i _U (t), i _V (t), i _W (t)) actually supplied to synchronous motor 100
The current i (t) of the phase, that is, the current of any of the U phase, the V phase, and the W phase may be used. i _U (t), i _V (t), or i _W (t) may be detected by the current detection means 102. The detected current i (t) is output from the saturation output means 10.
4 is input. Current command means 136, the above-mentioned current command value substituted into ^{_{(i U * (t),}} i V * (t), i W * (t)) to the equation for the d-axis current i _d and the q-axis current i _q Then, a current command value i ^* (t) is calculated. The saturation output means 104 includes:
The detected current i (t) is subtracted from the current command value i ^* (t) of that phase. The saturation degree output means 104 calculates an absolute value of the result of the subtraction, and integrates a current error e (t) which is a result of obtaining the absolute value. The result of the integration is input to the judgment value output means 106.

Instead of calculating the integral of the absolute value of the error, the saturation output means 104 may input the integral of the square of the error or the maximum value of the error to the judgment value output means 106. Since the fluctuation component increases, it is difficult to use the current error e (t) that fluctuates periodically for subsequent processing. Therefore, by integrating the current for one phase in the time domain, it is possible to obtain a DC value with a small enough variation for controlling the synchronous motor 100.

Although theoretically a value close to the DC component can be calculated using the currents of the three phases, the calculation is complicated because the square values of the currents of the u, v, and w phases are calculated and added. It is.

The judgment value output means 106 subtracts the reference e _ref set by the reference output means 108 from the integrated value of the current error e (t) as shown in (Equation 3), and the result is obtained by subtraction. The judgment value _Han is output.

[0087]

[Equation 3]

Here, the reference output means 108 changes the reference e _ref based on the integration time. Specifically, the integration time of the current error e (t) is a half cycle T of the current error e (t).
/ 2, the reference value e _ref is output by calculating (Equation 4). Alternatively, the reference e _ref may be obtained by calculating (Equation 5) using the speed ω. In addition,
Here, a half cycle of the current error e (t) is used as the integration time, but the integration time may be any time. However, since the current error e (t) changes periodically, the integration time is preferably an integral multiple of a half cycle.

[0089]

(Equation 4)

[0090]

(Equation 5)

Here, a large judgment value _Han means that a current error is large. In other words, it means that the q-axis current actually supplied to the synchronous motor 100 does not follow the q-axis current command value. This means that, in the high-speed rotation region of the synchronous motor 100, when the synchronous motor 100 runs in power because the voltage margin is small, the q-axis current that generates a torque commensurate with the rotation speed does not flow. When the synchronous motor 100 regenerates, it means that the q-axis current that generates a torque corresponding to the rotation speed flows too much. In such a voltage margin is small state, to be commanded output, in order to obtain the rotational speed or torque may be increased d-axis current i _d.

The case where the synchronous motor 100 is running is, specifically, a state in which the judgment value is large, and
0 to allow current to flow through the semiconductor switches Q1-
Even when Q6 (a part of the components of the input application means 138 in FIG. 1) is turned on, a necessary current does not flow.

[0093] fact that contrary to the judgment value H _an, is smaller, the current error is small. So this means that
This means that the current actually supplied to the synchronous motor 100 follows the current command value well. Judgment value H _an
Is small, if the synchronous motor 100 is powering, without changing the d-axis current i _d flowing in the current synchronous motor 100,
A q-axis current _iq equal to or greater than the q-axis current _iq currently flowing in the synchronous motor 100 can be made to flow, and the rotation speed of the synchronous motor 100 can be increased.

Even when the synchronous motor 100 is powered or regenerated, the d-axis current tends to flow too much. From the viewpoint of reducing the loss, it is preferable to reduce the d-axis current i _d. In the case need not particularly be added a d-axis current i _d is a non-salient pole machine, the d-axis current i _d may be zero.

[0095] determination value H _an, indicates whether a current command given to the synchronous motor 100 is able to actually achieve much. If the current command has not been realized, the d-axis current _id is increased so that it can be realized. If the current command can be realized, the current rotational speed or the current torque state is maintained, and d is set so that the efficiency of the synchronous motor 100 is maximized.
What is necessary is just to reduce the shaft current id.

As described above, the d-axis current command means 110 changes the d-axis current based on the output of the judgment value output means 106. For example, if H _an > 0, the d-axis current command means 1
Numeral 10 increases or holds the command value _id ^* of the d-axis current. the case that holds the command value of the d-axis current i _d ^* is a case in which the maximum value i _d ^* max command value of d-axis current id ^* is set in advance.

When H _an <0, the d-axis current command means 110 decreases the d-axis current command value _id ^* or holds the previous value. the case that holds the command value of the d-axis current i _d ^*, the command values of the d-axis current i _d ^* is a preset minimum value i
_d ^* min.

In general, in the case of a non-salient pole machine, the value advanced by adding _id ^* = 0 or slightly _id ^* is set to the minimum value _id ^* min.
Used as It should be noted that, in general, in the non-salient machine i _d ^* = 0
In this case, the efficiency of the non-salient pole machine becomes the best. However, when the iron loss of the non-salient pole machine is large, the iron loss can be reduced by slightly advancing the phase, slightly weakening the field and reducing the stator magnetic flux. Thereby, the iron loss and the copper loss can be balanced, and the efficiency becomes the highest.

When the reversal pole machine uses the reluctance torque, to generate the reluctance torque,
The phase is advanced to some extent (10 ° to 40 °). If not field weakening range, the command value of the d-axis current i _d ^* minimum i _d of ^*
min, for example when a 30゜Wo fixed amount of phase lead, i _d ^* m
in = i ^* · sin30in. (Details will be described later.) In the case of a weak magnetic field, specifically, (Equation 6)
Is calculated.

[0100]

(Equation 6)

[0102] Here, i _d ^* (i) and i _d ^* (i-1) represents a respective command values i _d ^* of the current and previous d-axis current.

The control operation including the integration operation of the above equation will be described in more detail.

If H _an > 0, d is satisfied until H _an = 0.
Axis current command means 110, a command value of the d-axis current i _d ^* is increased one by K ₁ · H _an every control operation. Such an operation can be performed by an integration operation. By performing such operation, the H _an, may be zero.

When the command value of the d-axis current is _id ^* = _id ^* max, the command value of the d-axis current is fixed at _id ^* max. And
When H _an = 0, when the load torque is constant, the d-axis current command means 110 keeps giving a constant d-axis current command value _id ^* .

Next, when the load torque decreases or the rotation speed decreases and H _an <0, d
The axis current command means 110 decreases the command value _id ^* of the d-axis current. When the synchronous motor 100 is balanced and H _an = 0, the d-axis current command means 110
Stop command value i _d ^* reduction of the axial current, give the command value i _d ^* and current command means 136 of the constant d-axis current. When the rotation speed is further reduced to a region where the field weakening is not required, the d-axis current command unit 110 gives the above-described minimum value _id ^* min to the current command unit 136. Even if a H _an, <0, so the command value of the d-axis current i _d ^* is below a minimum value i _d ^* min is d-axis current command section 110, the command value of the d-axis current i _d ^* Do not decrease.

Next, the q-axis current command means 130 converts the command value _iq ^* of the q-axis current to the error between the command speed ω ^* for commanding the rotation speed of the synchronous motor 100 and the actual speed ω of the synchronous motor 100. The calculation is performed using the constant K (Equation 7).

[0107]

(Equation 7)

The command value _iq ^* of the q-axis current is changed to the command speed ω
It goes without saying that a command may be issued independently of ^* .

The obtained command value of the d-axis current and the command value of the q-axis current are calculated by the current command means 136 (Equation 8).
The vector operation is performed as follows. As a result of the vector operation, the magnitude of the command signal of the combined current that is the current to be supplied to the synchronous motor 100 and the phase θ thereof are output.

[0110]

(Equation 8)

[0111] Here, if the combined current value I ^* is equal to or greater than the maximum current setting value imax, i _d ^* priority is high in, i _q ^* is given by equation (9).

[0112]

(Equation 9)

[0113] In this case, if you set imax = i _d ^* max, when the synchronous motor 100 is power running, the maximum current set value imax
Even if a command value _iq ^* of the q-axis current which is an excessive torque current exceeding
The command value _id ^* of the d-axis current is increased until the integrated value of the current error becomes the reference value. As the command value _id ^* of the d-axis current increases, the command value _iq ^* of the q-axis current decreases.

This means that the balance between the command value _id ^* of the d-axis current and the command value _iq ^* of the q-axis current is adjusted so that the synchronous motor 100 can output the maximum output. That is, when supplying the maximum current to the synchronous motor 100, the maximum torque can be realized.

Next, the input applying means 138 performs an operation for flowing a current based on the command value actually synthesized in the synchronous motor 100. The current command value (i
^{_{U * (t), i V}} * (t), by i _W ^* (t)) to determine the formula, based on a command instruction value of a current command value and the q-axis of the d-axis current, 120 degrees out of phase are different, u, v, and w
The three-phase current command values are output using a two-phase to three-phase conversion equation. Then, the saturation output means 104 compares the PWM current error e (t) with the triangular carrier signal of about 10 kHz. According to the pulse width modulation signal obtained by comparison,
The semiconductor switches Q1 to Q6 of each phase are controlled to supply a commanded current to the synchronous motor 100.

The judgment value output means 106 outputs the current error e
Subtracting the reference value e _ref from the integral value of (t), and outputs a determination value H _an, a result of subtracting. If H _an > 0,
The d-axis current command means 110 increases or holds the command value _id ^* of the d-axis current. If _Han <0, the d-axis current command unit 110 decreases or holds the command value _id ^* of the d-axis current.

[0117] That is, if H _an, is large in the state that does not give the indicated output outputs the indicated rotation speed and torque passing a q-axis current by adding a minimum of i _d. Conversely, when the judgment value _Han is small, the d-axis current _id
Is in a state in which the instructed output can be realized even if is slightly reduced, and the d-axis current command means 110 decreases the d-axis current _id and increases the efficiency. As a result, the d-axis current _id is automatically and optimally adjusted in terms of efficiency, and the field-weakening control of the synchronous motor 100 can be realized with high efficiency.

The discussion has been advanced on the non-salient pole type rotor shown in FIG. In the opposite case salient pole rotor shown in salient pole rotor and FIG. 6 (b), the already mentioned in addition to the d-axis current i _d of have weakened field control, subtracting the d-axis current i _d of reluctance torque portion to be described later or What is necessary is just to add.

It has been described that the d-axis current command means 110 performs control by an integral operation as shown in (Equation 6).
Further, it goes without saying that the same effect can be obtained even if the d-axis current command means 110 performs PID (proportional-integral-derivative) control as shown in (Equation 10).

[0120]

(Equation 10)

Here, Ka, Kb, and Kc are constants.

Further, even if a control method such as fuzzy control or adaptive control using a nonlinear gain is used, the command value _id ^* of the d-axis current can be obtained as long as an operation corresponding to integration is included.

The saturation output means 104 is provided for each phase of the semiconductor switches Q1 to Q6 for a half cycle of the current command signal.
Of the inverter can be detected by measuring the open period or the closed period of the inverter.

The three-phase currents (i _U (t), i
_{V (t), i W (} t)) not only calculates the saturation of one phase of the three-phase currents _{(i U (t), i} V (t), i
_W (t)) of the current detection means 1
02 may be detected, and the saturation output means 104 may calculate the average of the two-phase or three-phase saturation, respectively. By using the average value of the two-phase or three-phase saturation, the accuracy of controlling the synchronous motor 100 is improved, and the synchronous motor 100 is controlled.
Needless to say, the efficiency is improved.

When synchronizing with the cycle of the encoder detection signal or the like, as shown in (Equation 4) or (Equation 5), the reference value e of the error output from the reference value output means 108 according to the cycle and the rotation speed is obtained. Note that the _ref changes.

Here, when detecting the current flowing through the synchronous motor 100 at a constant period regardless of the rotation speed of the synchronous motor 100, it must be noted that the error integrated value changes depending on the detection timing.

[0127] In the first embodiment described above, judgment value H _an, obtained by determining the output unit 106, which had been entered in the d-axis current command means, even seeking H _an, with q-axis current The same effects as in the first embodiment can be obtained. In order to obtain _Han using the q-axis current, the following configuration is different from that of the first embodiment. The output _iq ^* of the q-axis current command unit 130 is input to the saturation output unit 104 (not shown).

[0128] Further, the saturation output unit 104, is also input q-axis current i _q obtained by the following.

The three-phase current values (i _U , i _V , i _W ) actually supplied to the synchronous motor 100 are detected by the current detecting means 102, respectively. In the case of detecting only the current values of two phases, it obtains the current value of the remaining one phase using the relationship of _{i U + i V + i W} = 0. Then, determined using the following equation current component i _q, expressed in d-q-axis showing the rotating coordinate system. (I _d need not ask.)

[0130]

(Equation 11)

When the saturation output means 104 outputs the q-axis current command value i
_The detected current value _iq is subtracted from _q ^* . A value obtained by integrating the current error e as a result of the subtraction is compared with a reference value e _ref, and a judgment value _Han as a result of the comparison is output.

In this case, the configuration of the saturation output means 104 is complicated, but since the required torque current _iq is managed directly, the torque of the synchronous motor 100 can be controlled with higher accuracy.

When the circuit for accurately separating the q-axis current component from the current flowing through the synchronous motor 100 is formed by an analog circuit, the configuration of the analog circuit becomes complicated. Therefore, in order to accurately separate the q-axis current component from the current flowing through the synchronous motor 100, it is desirable to use a digital circuit. Therefore, it is preferable that the feedback control signal operation including the d-axis current command unit 110 or the q-axis current command unit 130, the current command unit 136, the saturation output unit 104, and the judgment output unit 106 be digitized.

Further, the saturation output means 104 of the first embodiment may have the following configuration. First, the saturation output means 104 outputs 1 during a half cycle of the current error.
A case where the saturation of the inverter is detected based on a value obtained by integrating the difference between the phase command value and the current actually flowing through the synchronous motor 100 will be considered. When the operating voltage of the synchronous motor 100 is reduced, the rotation speed of the synchronous motor 100 decreases, and the half cycle of the current error increases. As a result, the integration time becomes longer, and the integrated value becomes larger. The integrated value is A
When the output is larger than the maximum output value of the / D converter, the integrated value is limited by the maximum output value of the A / D converter. In such a case, the gain of the integrator (not shown) of the saturation output means 104 is reduced so that the integrated value becomes smaller than the maximum output value of the A / D converter (not shown). Just fine. Changing the gain setting of the integrator as described above is very effective when the synchronous motor 100 is used at a low rotation speed. For example,
By employing a configuration in which the gain is switched by a switch (not shown) or a configuration in which the gain is changed by a variable resistor, the integrated value can be prevented from being limited to the maximum output value of the A / D converter. This expands the range of application of the control device.

Further, instead of providing the current detecting means 102 in the first embodiment, a torque detecting means (not shown) for measuring the torque of the synchronous motor 100 may be provided. In this case, the current command means calculates and outputs a command torque given to the synchronous motor 100 from the command value of the d-axis current and the command value of the q-axis current. The saturation output means 104 may subtract the measured torque from the command torque and output the result of the subtraction as the saturation. First
It is needless to say that the d-axis current is controlled even if the embodiment has such a configuration.

Further, the saturation output means 104 of the first embodiment may have the following configuration. The saturation output means 104 outputs a command value i ^* of at least one phase current ^.
The integrated value of the current value obtained by integrating (t) and the detected value i corresponding to the current actually flowing through the synchronous motor 100 are detected.
The saturation of the inverter is detected based on the difference from the integrated value of (t). As a result, an error due to the phase difference between the respective signals can be eliminated, and the current actually flowing through the synchronous motor 100 can be accurately managed.

Furthermore, the d-axis current command means 110 of the first embodiment described above may have the following configuration. When the d-axis current command means 110 is equal to or lower than the preset rotation speed, the command value of the d-axis current is held at the lower limit set value _id ^* min. Until the rotation speed increases, the command value of the d-axis current is set to a constant value. As a result, the output torque of the synchronous motor 100 is suppressed, so that the speed responsiveness of the synchronous motor 100 is sacrificed, but an efficient synchronous motor control device can be provided.

As shown in (Equation 6), the command value of the d-axis current is held between a preset upper limit value and a preset lower limit value. In particular, when the upper limit value is low, the response is similarly sacrificed, but the control device is efficient.

Note that the reference output means may change the reference value based on at least one of the number of revolutions and the current command value (this configuration is not shown). With such a configuration,
The following effects are obtained. When the rotation speed of the synchronous motor increases, the iron loss becomes too large compared to the copper loss. Therefore,
increasing the d-axis current i _d, by advancing the field weakening, it is possible to reduce the magnetic flux, reducing the core loss.
This balances copper loss (proportional to the square of the current) with iron loss. As a result, the efficiency can be further improved. Therefore, it is effective to reduce the reference value as the rotation speed increases and to advance the field weakening.

Second Embodiment Hereinafter, a permanent magnet synchronous motor 1 according to a second embodiment of the present invention will be described.
00 will be described with reference to the drawings. Second embodiment of the invention, forcibly changing the i _d,
A control device which can most efficiently to adjust the d-axis current i _d to be better.

FIG. 7 is an overall view showing the configuration of the control device of the permanent magnet synchronous motor 100 according to the second embodiment of the present invention. In the second embodiment, a change timing output unit 250, a d-axis current change unit 252, a speed detection unit 254, and a d-axis current update unit 256 are added to the first embodiment. Further, reference output means 208, d-axis current command means 2
10 and the q-axis current command means 230 are different from the reference output means 108, the d-axis current command means 110, and the q-axis current command means 130 of the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

A permanent magnet synchronous motor 100 shown in FIG.
The operation of the control device will be described.

The change timing output means 250 forcibly changes the d-axis current when the synchronous motor 100 is determined to be in the steady state from the rotational speed of the synchronous motor 100 and the d-axis current detected by the speed detection means 254. The change timing to be output is output to the d-axis current changing unit 252. Here, the steady state refers to a case where the rotation speed and the d-axis current are within a certain range for a certain period. The d-axis current is detected by the current detecting means 102.

Next, when the q-axis current command means 230 and the d-axis current change means 252 receive an instruction from the change timing output means 250, the combined current value is kept constant so as to satisfy (Equation 12). The d-axis current decreases as it is. d
When the axis current _id and the q-axis current _iq are sine waves, decreasing the d-axis current while keeping the combined current value constant is equivalent to changing the phase of the command value of the combined current. d-axis current i _d ratio is large accustomed if the current phase advances.

[0145]

(Equation 12)

For example, _iq ^* = 10A, _id ^* = 6A (I ^*
= 11.66 A), the change timing output means 25
If 0 is determined to be a steady state, q-axis current command unit 230 and the d-axis current changing means 252, i _q ^* = 10.12
^{_{A, i d * = 5.8A (}} I * = 11.66A) respectively varied as.

It is assumed that the speed detecting means 254 has already detected the rotation speed in the steady state. Speed detecting means 254 detects the rotational speed after changing the d-axis current i _d. The d-axis current updating means 256 outputs the d-axis current _id
Is compared with the rotation speed before changing the d-axis current id. After changing the d-axis current i _d, when the rotational speed is increased, changes the command value of d-axis current i _d to d-axis current after changing the d-axis current i _d. This is because, in such a state, the d-axis current _id is additionally supplied to the synchronous motor 100, and the efficiency is poor. The d-axis current updating unit 256 receives the command value _id ^* of the d-axis current via the d-axis current changing unit 252.
Further, after changing the d-axis current i _d, when the rotational speed decreases, the current command means 136, a d-axis current i _d before changing the d-axis current i _d of d-axis current i _d Used as a command value. Note that if the update command value of the d-axis current i _d, the command value of the updated d-axis current i _d is required to examine continuously whether the optimal value. Similarly, d-axis current _id
By the first change, even when the rotational speed is decreased, by increasing the d-axis current i _d checks whether or not the rotational speed increases.

[0148] When the rotational speed is increased, it continues to change the d-axis current value i _d. That is, it is necessary to slide into changes to the d-axis current value i _d is the optimum value. During the change operation, the switch of the current command means 136 in FIG. 7 is connected to the current command means 136 and the d-axis current change means 252.

[0149] Further, when there is no external torque command or the like, such as to increase the d-axis current i _d is changed timing output means 250, and keeps the permission to change the d-axis current i _d to d-axis current changing means 252 Give. In this case, the d-axis current is updated repeatedly.

[0150] In the case of change the d-axis current i _d, the time delay until the rotational speed of the synchronous motor 100 is sufficiently changed is relatively long, a period of time after changing the d-axis current i _d (The fixed period is longer than the time delay), the rotation speed of the synchronous motor 100 may be determined. By the above-described operation, the d-axis current updating unit 256 can obtain and output the optimal command value of the d-axis current _id ^* .

Here, if the change timing output means 250 determines that it is in a steady state and the determination value of the determination value output means 106 is positive, the reference output means 208 outputs the updated d-axis current _id ^*. And outputs a new reference value based on the command value. In other words, when the command value of the d-axis current _id ^* decreases, the reference output unit 208 increases the reference value according to the reduced amount. Conversely, when the command value of the d-axis current _id ^* increases, the reference output means 208 decreases the reference value in proportion to the increased amount. The reference output means 1
08 is a d-axis current changing means 252 and a d-axis current updating means 25.
6, a signal indicating the state of the synchronous motor 100 is received.

Next, the case where the judgment value of the judgment value output means 106 is negative will be described. In the case of non salient pole machine, d-axis current _id
May be zero or a preset value as described above. However, in the case of the reverse salient pole machine, the d-axis current _id is supplied because the reluctance torque of the second term of (Equation 13) can be used even in the weak field region.

[0153]

(Equation 13)

When the d-axis current updating means 256 operates in the normal region other than the field weakening region, the d-axis current command value _id ^*
The case where the coefficient of the arithmetic expression of (Expression 14) is changed based on the changed value of is described. When the command value _id ^* of the d-axis current increases, K in (Equation 14) is increased, and when the command value _id ^* of the d-axis current decreases, K is decreased. In that case, the actual control operation will be described below. The d-axis current command means 210 calculates a command value I ^* of the combined current. q-axis current command means, a command value i _d of the command value I ^* and the d-axis current of the calculated combined current ^* receiving (not shown). q-axis current command means, based on the equation (8) using the command value i _d of the command value I ^* and the d-axis current of the calculated combined current ^*, q
The command value _iq ^* of the shaft current is obtained. By changing the value of the coefficient K, the rotation speed and the torque of the synchronous motor change.

Note that the normal region is a region indicated by oblique lines in FIG. Further, an area not shown by hatching in FIG. 14 is an operation area newly increased by performing the field weakening control.

[0156]

[Equation 14]

The subsequent operation is the same as in the first embodiment, and a description thereof will be omitted.

As described above, by adding means for judging the steady state of the synchronous motor 100 and adjusting the d-axis current _id to an optimum value, highly efficient operation can be performed even with aging and environmental changes. A possible control device can be realized.

[0159] In the reverse salient pole machine, to change the d-axis current i _d of the normal region, it is desirable that the torque is often used. Further, it is desirable that the change timing output means 250 also considers this. Because
There is no sense to make changes of the d-axis current i _d a less does not use the operating point.

[0160] In the normal area of the non-salient machine, does not vary much from near zero to the d-axis current i _d is set, d
Since there is no need to change the axis current _id , the change timing output means 250 does not output the change timing in the normal region.

[0161] The minimum value of d-axis current i _d is the value of d-axis current i _d of the case without the field weakening, not zero in the reverse salient pole machine.

Third Embodiment A control device for a permanent magnet synchronous motor 100 according to a third embodiment of the present invention will be described with reference to the drawings. In the third embodiment of the present invention, the d-axis current i set on a table or the like is used.
_This is a control device of the permanent magnet synchronous motor 100 in which the responsiveness is improved by using the initial value of _d .

FIG. 8 is an overall view showing the configuration of the control device of the permanent magnet synchronous motor 100 according to the third embodiment of the present invention. In the third embodiment, a current initial value output unit 340, a speed detection unit 254, and a q-axis current change amount unit 370 are added to the first embodiment. further,
The d-axis current command means 310 is different from the d-axis current command means 110 of the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The operation of the control device of the permanent magnet synchronous motor 100 configured as shown in FIG. 8 will be described below.

If the command value of the q-axis current input from the outside is larger than a preset value, the current initial value output means 3
40 is a command value of the q-axis current from the outside and the speed detecting means 3
54 corresponds to the rotational speed and output, the initial value of the command of the d-axis current based on the value given in advance in a table or the like i _d _
^* Output ini.

Here, the current initial value output means 340
According equation (2), and outputs a d-axis current i _d to the speed detection means 254 is calculated from speed and torque detected.

The d-axis current _id is calculated using a value calculated in real time based on a calculation formula such as (Equation 2) or a value actually obtained by experiment based on various data such as terminal voltage and temperature. Is also good.

The d-axis current command means 310 uses the value output from the current initial value output means 340 as the initial value of the d-axis current value. The d-axis current command unit 310 increases or holds the d-axis current when the determination value is positive, similarly to the d-axis current command unit 110 of the first embodiment. When the judgment value is negative, the d-axis current command unit 310 decreases or holds the d-axis current.

[0169] preset in a table or the like d-axis current i _d
By using the initial value i _d _INI, it is possible to shorten the time d-axis current to converge to the optimum d-axis current to operate the synchronous motor 100.

Also, the required q-axis current command value i _q ^*
Is shortened, and the responsiveness of the synchronous motor 100 is improved.

The q-axis current change amount means 370 may receive the command value of the q-axis current from the q-axis current command means and may hold the command value of the q-axis current at least two times before the present time. . set low set value of the change in the command value from the outside of the q-axis current, in the case of H _an,> 0, q-axis current variation ^{_{{i q * (i-1}} ) -i q * (i-2) Using｝, the d-axis current command value means 310 can calculate the d-axis current by the following equation.

[0172] ^{_{i d * (i) = i}} d * (i-1) + K · H an + K q · {i q * (i-1) -i q * (i-2)} Similarly i _q ^* of Since the d-axis current _id ^* is given according to the amount of change, the speed response is improved.

Fourth Embodiment A control device for a permanent magnet synchronous motor 100 according to a fourth embodiment of the present invention will be described with reference to the drawings. Fourth embodiment of the present invention, the d-axis current i _{ratio d} is changed when the synchronous motor 100 is regenerated, greater than d-axis current i _{ratio d} is changed when the synchronous motor 100 is the power running. Thus, in the fourth embodiment, the time during which the d-axis current _id is optimum can be shortened, and furthermore, the synchronous motor 100 can be controlled safely without sudden braking.

First, regeneration and power running will be described.

As described above, power running is a state in which the electric motor is generating mechanical output. In other words, the power of the power supply is being supplied to the electric motor. When the battery is used, the battery is being discharged. Regeneration is a state in which the electric motor is converting mechanical energy into electric energy. In other words, power is being input to the power supply. When the battery is used, the battery is being charged. Sign of regeneration of the q-axis current i _q will sign opposite powering the q-axis current i _q. Therefore, as shown in FIG. 9, the induced voltage ωψ and R · iq are vectors in opposite directions.

Next, consider the case where the synchronous motor 100 is rotating at high speed and the d-axis current _id is small. In this case, the synthesized voltage value V is outside the voltage limiting circle and cannot exist stably (FIG. 9A). By q-axis current i _q flows more than the command value, and the vector R · iq induced voltage ωψ and reverse increases, synthesized voltage value are input into the V limit circle. In this way, it flows a large q-axis current i _q than the command value (FIG. 9 (b)). Here, when the motor is regenerating, the q-axis current command value means a negative torque command value. That is, the commanded negative torque is not realized. In other words, a negative torque greater than the commanded value is generated, and the electric motor is braked. In order to avoid the brake is applied to the motor may do it by passing a d-axis current i _d of sufficient magnitude to the electric motor (FIG. 9 (c)). As if the motor is powering, the d-axis current i _d may with minimal current to return to the voltage limit circle, given a d-axis current i _d to the above minimum value d
Less efficient by copper loss generated by passing the axis current i _d.

FIG. 10 is an overall view showing the structure of the fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in that
The power running regeneration judging means 420 and the change ratio output means 422 are added. Except for the added means, the configuration is the same as that described in the first embodiment.

The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

A judgment value is obtained in the same manner as in the first embodiment.
The calculation of (Equation 15) is performed by the d-axis current command means 110 based on the obtained judgment value.

[0180]

(Equation 15)

By the way, the rate at which _id ^* changes is (Equation 1)
It may be determined by the predetermined constant values K1 and K2 in 5). Note that these values may be determined as follows.

[0182] The power running regeneration determination means 420
It is determined whether the operation state of 00 is power running or regeneration, and the determined operation state is input to the change ratio output means 422.

More specifically, a q-axis current command unit 13 described later
When the sign of the command value _iq ^* of the q-axis current commanded by 0 is positive, it is determined that the vehicle is running, and when it is negative, it is determined that it is regenerating.

The change ratio output means 422 outputs K1 and K2 for power running during power running, and outputs K1 and K2 for regeneration during regenerative driving.
Enter 0. Specifically, K1 and K2 may be given in a table.

As described above, d depends on the operating state of the motor.
By changing the change ratio of the command value _id ^* of the shaft current, it is possible to realize the field weakening control of the synchronous motor 100 that is realistic. In addition, K1, K2 of power running and regeneration
Takes a value of 1/100 to 1/2 of the current limit value. The current limit value Im is set between the semiconductor switches Q1 to Q1.
It is determined by the maximum current that can flow through Q6 or the maximum current that can flow through each wiring. Further, the maximum value i _d ^* max of the command value of the d-axis current, Im · sin60 ° ≦ i
_d ^* max ≦ Im · sin 90 °. Also, the minimum value i _d ^* min of the command value of the d-axis _{current, Im · sin0 ° ≦ i d} * min ≦ Im
・ It is a value of sin 40 °.

The change ratio may be given by the following equation.

[0187] change ratio K _{is, K = K 0 · {i} d * (i-1) -i d * (i-2)} / {H an (i-1) -H a (i-2)} Can be expressed as

However, since K cannot be calculated in the first time when H _an > 0, K = K _min (K _min <
K ₀ <1).

[0189] That is, d-axis current i for the current H _an,
calculates the degree of influence of _d, by using that value as the change rate, it is possible to obtain the required d-axis current i _d quickly.

Here, the rate of change corresponds to the gain of the control system, and increasing the rate of change means setting the gain so as to shorten the settling time. As described above, it is needless to say that the change rate K can be similarly set by using a control method such as PID.

[0191] As already mentioned, responsive unless rapid addition d-axis current i _d to the synchronous motor 100 is deteriorated as needed. When the d-axis current _id is added too much, the efficiency is deteriorated but the response is not deteriorated. Even efficiency becomes worse, if it is desired to obtain a quick response property, the change ratio when the d-axis current i _d is increased, may be larger than the rate of change in the case where i _d is reduced. As a result, a control device with good responsiveness can be obtained.

However, for example, the synchronous motor 100
When the amount of energy that can be given to the motor is small, it is desired to operate the synchronous motor 100 with high efficiency even if the response becomes poor.

[0193] In this case, the change ratio when the d-axis current i _d is increased, may be set smaller than the change rate in the case where i _d is reduced.

As described above, it is possible to switch between setting of importance on responsiveness and efficiency.

The fourth embodiment may be provided with an external switch in order to switch between the setting of responsiveness and the setting of efficiency.

Further, by changing the state of the external switch continuously or intermittently, the rate of change of the command value of the d-axis current can be changed, and a desired response speed can be easily obtained. The external switch is operated by the user.

It is needless to say that even if the command value (command speed) of the q-axis current is changed, the same effect as the case where the change rate of the d-axis is changed is obtained.

As described above, in the high-speed rotation range of the synchronous motor 100, the d-axis current _id is small and the synchronous motor 1
When 00 is running, the q-axis current _iq does not flow, and the required torque cannot be output. On the other hand, when the synchronous motor regenerates, the q-axis current _iq flows too much and suddenly (1
Within seconds) a negative torque is generated. The generation of a sudden negative torque causes a sudden braking of the synchronous motor. It is very dangerous that the brake of the synchronous motor is suddenly braked when the synchronous motor is operating. In order to safely operate the synchronous motor, in the case of regeneration, the rate of change of the d-axis current _id ^* is increased. As a result, a sufficiently large d-axis current id flows to the synchronous motor promptly, and it is possible to prevent sudden braking. Therefore, the synchronous motor rotates safely.

In equation (3), when the reference e _ref is set to be large, the judgment value _Han becomes small.

[0200] Then, it settles the command value i _d ^* is small value of d-axis current obtained by the calculation of equation (15). Conversely, when the reference e _ref is set small, the judgment value _Han increases. This command value i _d ^* of settled value of d-axis current by setting the reference e _ref indicates to be controlled.
Therefore, when the reference e _ref is set large, it is possible to perform high-efficiency control in which _id ^* does not easily flow. On the other hand, when the reference e _ref is set to be small, the command value _id ^* of the d-axis current is large, and control faithful to the torque command can be performed. Therefore, in the case of power running, the reference e _ref is set large, and the synchronous motor 100 is controlled with high efficiency. In the case of regeneration, by setting the reference e _ref small, the synchronous motor 100 is controlled so as to be faithful to the torque command, that is, to prevent sudden braking.

[0201] As shown in FIGS. 2 and 9, the sign of the q-axis current i _q in the case of power running is different from the sign of the q-axis current iq in the case of regeneration. Then, when the operating state changes changes the sign of the q-axis current i _q, d-axis current i _d to be the minimum required to change in a moment. Actually, FIGS. 2 and 9
As can be seen from, d is needed when the regenerative than the d-axis current i _d to be required when the power running and focusing on R · i _q
Is less towards the axis current i _d.

[0202] Therefore, when said operating state changes from power running to regeneration, minimum The required d-axis current i _d is decreased, when said operation state is changed from the regeneration to power running,
D-axis current i _d to be the minimum required increases. To respond quickly to changes in such d-axis current i _d, when the operating state changes, arithmetic expressions and tables, etc. necessary to change the command value i _d ^* of the d-axis current based on It is.

Specifically, an operation as shown in (Equation 16) is performed.

[0204]

(Equation 16)

Here, Ka and Kb are proportional constants, and ω ₀
Is the maximum number of revolutions when the field weakening control is not performed. Note that an operation such as Equation 17 may be used.

[0206]

[Equation 17]

Here, the new command value _id ^* new of the d-axis current is
This is the command value _id ^* of the d-axis current that is newly set after the operating state changes. i _d ^* prev is before the operating state to change d
This is the command value _id ^* of the shaft current. i _q ^* prev is a command value i _q of the q-axis current before operating condition changes ^*. _iq ^* now is the command value _iq ^* of the q-axis current after the operating state has changed. Also, Kc,
Kd is a constant. By making these settings,
To changes in operating conditions, it is possible to quickly respond to the d-axis current i _d.

It should be noted that the command value _id ^* of the d-axis current is changed only once after the operation state changes, using (Equation 16) and (Equation 17). In the second and subsequent times, d
The command value _id ^* of the shaft current is determined using (Equation 15).

Already, for the reverse salient pole rotor, the total d
Command value of the axis current i _d ^* = it was already mentioned given by the command value of the reluctance torque portion of d-axis current i _d ^* + command value of the d-axis current of the weak field磁分i _d ^*. (The stability of the synchronous motor 100 is affected by the d-axis current change rate of power running and the allowable value of the braking torque, but the synchronous motor 100 operates almost stably).

[0210] However, when the command value i _q ^* of the q-axis current and the torque command is reduced, the command value i _d of the reluctance torque portion of the d-axis current ^* decreases. As a result, the command value _id ^* of the total d-axis current decreases. Therefore, in the weak field region,
When _iq ^* decreases from a large value and gradually changes to regeneration, if the allowable value of the braking torque is small, the allowable value of the braking torque may be exceeded. Therefore, when the command value _iq ^* of the q-axis current rapidly decreases, the command value i of the q-axis current
_In conjunction with _q ^* , the d-axis current command value _id ^* is prevented from suddenly decreasing. That is, the command value of the reluctance torque portion of d-axis current i _d ^* is not reduced, so as to reduce only the command value of d-axis current of the weak field磁分i _d ^*, operating the control device.
As a result, it is possible to prevent the command value _id ^* of the total d-axis current from suddenly decreasing. Further, a braking torque is generated within an allowable value for safely operating the synchronous motor 100.

[0211] In a rotor structure that can use reluctance torque, consider the case where the powering regeneration judging means 420 outputs regeneration. For example, when a d-axis current corresponding to the field weakening is supplied to the synchronous motor 100, a reluctance braking torque is generated by the d-axis current. Therefore, when it is desired to apply a constant braking torque to the synchronous motor 100, the amount of the q-axis current is reduced by the amount newly used as the d-axis current to obtain the reluctance braking torque (the amplitude of the q-axis current is reduced). ) Gives a constant braking torque and realizes stable operation.

Fifth Embodiment A fifth embodiment of the present invention will be described with reference to the drawings.

The fifth embodiment of the present invention is a control device for a permanent magnet synchronous motor 100 that can obtain a large amount of regenerative current generated by a braking torque and can achieve high efficiency.

FIG. 11 is a block diagram showing the configuration of the fifth embodiment of the present invention. In the fifth embodiment, the speed detecting means 254 is added to the fourth embodiment, and the change rate output means 42 is added.
2. The current detection means 102, error output means 104, judgment value output means 106, and reference output means 108 are deleted. Further, the q-axis current command means 530 of the fifth embodiment
Is different from the q-axis current command unit 130 of the fourth embodiment.

The operation of the control device of the permanent magnet synchronous motor 100 configured as described above will be described. Fifth
In the embodiment, the synchronous motor 100 is controlled by applying the d-axis current _id ^* and the q-axis current _iq ^* in a table or the like without performing the feedback control.

The difference from the already described embodiment is that the d-axis current command means 510 outputs the command value _iq ^* of the q-axis current output from the q-axis current command means 530 and the rotational speed output from the speed detection means 254. The command value _id ^* of the d-axis current is given by a table or an arithmetic expression based on

Here, when the power running regeneration judging means 420 outputs the regeneration and does not generate the field weakening, the command value of the d-axis current is set to zero, or the sign of the command value of the d-axis current of the power running is The command value of the d-axis current is output with the opposite sign. The fifth embodiment is effective for a synchronous motor having a structure that can use reluctance torque. This is because, when the regeneration as is clear from equation (13), when _{i q <0, i d <} 0, the magnet torque of the first term acts as a braking torque. However, the reluctance torque works for power running. As a result, the total braking torque is reduced, and the regenerative current with respect to the braking torque can be increased.

Although the fifth embodiment does not use the feedback control, it goes without saying that the above-described control can be applied to the feedback control. That is, when the value output by the judgment value output means is negative, it is regarded that the field is not in the field-weakening region, and similarly, the command value of the d-axis current is set to zero, or the sign of the command value of the d-axis current of power running is opposite The d-axis current command value is output with the sign of.

When the value output from the judgment value output means is positive,
To control the braking torque, it is as already mentioned to i _d> 0.

Sixth Embodiment Next, a sixth embodiment of the present invention will be described with reference to the drawings. A sixth embodiment of the present invention relates to a synchronous motor 1
This is a control device for the permanent magnet synchronous motor 100 that measures the voltage supplied to the motor 00, determines the maximum value of the command value of the d-axis current based on the voltage, and can increase the efficiency.

FIG. 12 is a block diagram showing the configuration of the control device for the electric motor according to the present embodiment. The sixth embodiment is different from the first embodiment in that the voltage measuring means 640 and the d-axis current maximum value output means 6
42 is added. The means other than the added means are the same as those described in the first embodiment. Therefore,
The description of the same operation is omitted. FIG.
The operation of the sixth embodiment shown in FIG. 2 will be described below.

The voltage V supplied to the synchronous motor 100 is measured by the voltage measuring means 640 and output. And
The voltage V is input to the d-axis current maximum value output means 642.
The d-axis current maximum value output means 642 calculates and outputs the d-axis current maximum value _id ^* max from the voltage V ( _id ^* max is calculated by (Equation 18) described later). The voltage V can be obtained by measuring the voltage between the terminals a and b of the inverter shown in FIG.

Then, the d-axis current maximum value _id ^* max is input to the d-axis current command means 110, and is used when calculating (Equation 6).

The subsequent operation is the same as in the first embodiment, and will not be described.

As described above, the maximum value of the command value of the d-axis current can be changed by the voltage supplied to the synchronous motor 100. As a result, a d-axis current for generating an optimum total current can be provided.

When a power source such as a battery is used, the terminal voltage decreases as the discharge proceeds. Therefore, the voltage supplied to the synchronous motor 100 decreases, and the total current that can flow through the synchronous motor 100 decreases. Here, when the maximum value of the d-axis current is constant, the ratio of the d-axis current to the total current is large, and the d-axis current is flowing too much. As described in the description of the first embodiment, d
The axis current only needs to flow at the minimum necessary. Excessive d-axis current indicates a decrease in efficiency. Synchronous motor 1
The smaller the voltage supplied to 00, the smaller the maximum value of the command value of the d-axis current may be.

Specifically, the calculation is performed as shown in (Equation 18).

[0228]

(Equation 18)

Here, Kbattery is a constant. In addition,
i _d ^* max it is needless to say that it may be given by other functions or tables relating to voltage V.

When the voltage applied to the synchronous motor decreases, the maximum value of the command value of the d-axis current decreases. As a result, a d-axis current for generating an optimum total current can be given, and there is an effect of preventing a decrease in efficiency.

The configuration described above may be applied to the configuration using no feedback described in the fifth embodiment. in this case,
Similarly, there is an effect of preventing a decrease in efficiency.

Seventh Embodiment Next, a seventh embodiment of the present invention will be described with reference to the drawings. In the seventh embodiment, various driving situations can be realized by determining the driving situation and setting a reference in accordance with the driving situation.

FIG. 13 is a block diagram showing the configuration of the seventh embodiment. In the seventh embodiment, the driving situation determining means 750 is added to the first actual finger example. The reference output means 108 of the first embodiment is different from the reference output means 708 of the seventh embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and the description of the operation is omitted.

The operation of the seventh embodiment shown in FIG. 13 will be described. First, the relationship between the reference value, the command value of the d-axis current, and the operation status will be described. When the reference value is changed, the command value of the d-axis current changes. This is because a large reference value allows a large degree of saturation (current error), which means that a sufficient d-axis current need not flow through the synchronous motor 100. Therefore, if the reference value is large, the command value of the d-axis current becomes small. This is clear from the property of (Equation 6). Conversely, when the reference value is small, the command value of the d-axis current increases. By changing the reference value in this way, the command value of the d-axis current can be controlled.

Here, when a torque is required, an operating condition in which the efficiency is reduced but the torque is emphasized is selected, and a reference value suitable for the operating condition is given. Based on this reference value, a command value for the d-axis current is generated, and the required torque is realized. On the other hand, in the normal operation, a high-efficiency operation state that emphasizes efficiency is selected, and a reference value appropriate for the operation state is given. Based on this reference value, a command value of the d-axis current is generated, and high efficiency is realized. Based on the above concept, the synchronous motor 100
Is performed.

The operating condition determining means 750 outputs one of two operating conditions, ie, an operating condition focusing on efficiency and an operating condition focusing on torque. For example, the setting of the operation state can be easily switched by an external switch. Then, the driving status is input to the reference output means 708. The reference output means 708 determines a reference value according to the driving situation. Specifically, a table is created in advance using theoretical formulas and experiments. The table associates each operating condition with each reference value. Then, the corresponding reference value is output and input to the judgment value output means 106.

The subsequent operation is the same as that of the first embodiment, and the description is omitted.

As described above, the synchronous motor 100 is normally operated with high efficiency, and only when the torque is required, the operating condition that emphasizes the torque is selected, and the required torque is output.

It should be noted that although the operating condition determining means 750 can output only two operating conditions, it goes without saying that one operating condition may be output from two or more operating conditions.

Next, when the operating condition determination means determines that the torque is to be emphasized when giving a command equal to or more than the preset maximum value of the combined current value, the reference output means outputs a smaller reference value than when the efficiency is emphasized. . This makes it possible to automatically switch between the torque-oriented and the efficiency-oriented settings based on the value of the total current command value. In FIG. 14, the region where the torque is emphasized and the region where the efficiency is emphasized are the regions generated when the field weakening control is performed. The normal region is a region indicated by oblique lines in FIG.

It is needless to say that a similar effect can be obtained by automatically switching between the torque-oriented setting and the efficiency-oriented setting using the torque current or two signals of the torque current and the rotation speed instead of the combined current.

As described above, the efficiency depends on the d-axis current i.
_It becomes worse as _d increases. Therefore, efficiency-oriented driving
When commanded by an external switch, etc., the following 1-3
Is considered.

[0243] 1. Decrease the maximum value of the combined current.

[0244] 2. The maximum rotation speed of the synchronous motor 100 is reduced.

[0245] 3. i to reduce the maximum value of the ratio of i _d (advance angle of the current phase) with respect to _q. That is, the efficiency can be improved by suppressing reduce the maximum value of i _d than the torque emphasis.

The operating ranges of the non-salient pole motors 1 to 3 are shown in FIGS. 15A to 15C (FIG. 15 shows the relationship between torque and rotation speed). As shown in FIGS. 15A to 15C, the synchronous motor 100 may be controlled to emphasize the torque or the efficiency.

It is needless to say that the above configuration can be applied to the configuration using no feedback described in the fifth embodiment.

Eighth Embodiment Next, an eighth embodiment of the present invention will be described. In the eighth embodiment, the judgment value of the d-axis current and the reference value of the q-axis current are set separately, and the set value of the d-axis current and the setting value of the q-axis current can be controlled separately. It is.

FIG. 16 is a block diagram showing the structure of the eighth embodiment. In the eighth embodiment, the judgment value output means 106 and the reference output means 108 are deleted from the first embodiment, and the d-axis judgment value output means 806, the q-axis judgment value output means 807, d
It is obtained by adding axis reference output means 808, q axis reference output means 809, and q axis current change means 831. 8th
The d-axis current command unit 810 and the q-axis current command unit 830 of the second embodiment are different from the d-axis current command unit 110 of the first embodiment.
And q-axis current command means 130.

The same components as those of the first embodiment are denoted by the same reference numerals, and the description of the operation is omitted.

The operation of the eighth embodiment will be described below.

The saturation output means 104 integrates and outputs the current error e (t) obtained by subtracting the detected current value i (t) from the actual current command value i ^* (t). The integrated value is output to the d-axis judgment value output unit 806 and the q-axis judgment value output unit 8.
07. The d-axis determination value output means 806 subtracts the reference e _refd set in the d-axis reference output means 808 from the integrated value of the current error e (t) as shown in ( _Equation 19). The d-axis judgment value output means 806 outputs a judgment value H _and which is a result of the subtraction.

Similarly, the q-axis judgment value output means 807 subtracts the reference e _refq set in the q-axis reference output means 809 from the integrated value of the current error e (t) as shown in ( _Equation 19). I do. The q-axis judgment value output means 807 outputs a judgment value _Hanq which is a result of the subtraction.

[0254]

[Equation 19]

As in the first embodiment, a half cycle T / 2 of error (Equation 20) or a velocity ω is used (Equation 2).
References e _refd and e _refq are obtained and output by the calculation of 1).

[0256]

(Equation 20)

[0257]

(Equation 21)

Subsequently, the d-axis current command means 810 determines the command value of the d-axis current as in the first embodiment. However, H _an, in equation (6) is replaced with the case H _and the eighth embodiment.

[0259] Incidentally, in the case of non-salient motors, more commonly the d-axis current i _d is less efficient. Therefore, the maximum characteristic can be suppressed a little, but the upper limit of the d-axis current value may be suppressed to about half of the maximum current value in order to prevent a decrease in efficiency. In such a case, the commanded q-axis current cannot flow because the d-axis current is kept small.
Therefore, the command value of the q-axis current may be determined as follows.

[0260] q-axis current command section 830 outputs a command value i _q ^* _O q-axis current given by the calculations, and the like (8), and inputs the q-axis current changing means 831. As shown in equation (22), is positive are judged value H _ANQ output from the q-axis determination value output means 807, the upper limit of the command value of the d-axis current i _d
^In the case of ^* max, the q-axis current changing means 831 reduces the q-axis current command value _iq ^* that is actually given from the previous q-axis current command value by the same calculation as the d-axis current change. Judgment value is negative, when the command value of the d-axis current is the upper limit i _d ^* max, and changes the command value i _q ^* (i) is less than or equal to i _q ^* _O,
By increasing the command value of the q-axis current by the q-axis current changing unit 831, the command value _iq ^* of the q-axis current can be given as a current value that can be actually supplied to the synchronous motor 100.

[0261] When not meet the above condition, the q-axis current changing means 831, without changing the i _q ^* _O, and outputs the current command unit 136 as a command value of q-axis current.

[0262]

(Equation 22)

Here, q-axis current command values _iq ^* (i) and _iq
^* (i-1) indicates the current and previous command values of the q-axis current iq.

Next, the following effects are produced by changing the two reference values and controlling the current command value. Here, if the reference value of the d-axis current and the reference value of the q-axis current are the same, the command value of the d-axis current and the command value of the q-axis current cannot be controlled separately. However, by giving the reference value of the d-axis current and the reference value of the q-axis current separately, it is possible to output the determination value of the d-axis current and the determination value of the q-axis current, respectively. Therefore, in the eighth embodiment, the command value of the d-axis current and the command value of the q-axis current can be controlled separately.

Next, let us consider a state where the required d-axis current is slightly larger than _id ^* max and the d-axis current is increasing according to (Equation 6). Since the d-axis current _id ^* is small, the current error is large, and since the d-axis judgment value is positive, the d-axis current _id ^* tends to increase according to (Equation 6). Eventually, the command value _id ^* of the d-axis current reaches _id ^* max.

If the d-axis current reference value and the q-axis current reference value are the same, the d-axis current determination value and the q-axis current determination value become the same. Since the q-axis judgment value is positive, (Equation 2
2), the command value _iq ^* of the q-axis current decreases. Then, the setting is performed when the command value _iq ^* of the q-axis current becomes slightly smaller. If the current error is reduced due to noise or the like in the control system, the command value i of the q-axis current
_q ^* increases and becomes larger than iq * _o. On the other hand, the command value _id ^* of the d-axis current decreases. As described above, as a result of adding noise to the control device of the present invention, control of the command value _id ^* of the _d- axis current and control of the command value _iq ^* of the q-axis current are repeated.

Since the current error is large, (Equation 22)
Accordingly, the command value _id ^* of the d-axis current becomes smaller. As a result, the current error decreases, and the command value _iq ^* of the q-axis current increases according to (Equation 22). The command value _iq ^* of the q-axis current is i
_q ^* to become larger than _O, the command value of q-axis current i _q ^* is i
Set to _q ^* _o. On the other hand, according to (Equation 6), the command value _id ^* of the d-axis current decreases. As a result, the current error is sometimes as repeatedly carry out the command value i _q ^* is the control of the command value i _d ^* of the control and the q-axis current of d-axis current so that it becomes larger again.

Therefore, the reference value of the d-axis current is smaller than the reference value of the q-axis current and is in the same state as in the previous paragraph, that is, the required d-axis current is slightly larger than _id ^* max. Consider a state in which the d-axis current is increasing due to Since the d-axis determination value is positive, _id ^* increases according to (Equation 7). Eventually, the command value _id ^* of the d-axis current becomes _id ^* ma
reaches x. Here, since the reference value of the d-axis current is smaller than the reference value of the q-axis current, the q-axis determination value becomes negative. Therefore, the command value _iq ^* of the q-axis current tends to increase. However, the command value of q-axis current i _q ^* is to become larger than the i _q ^* _O, after all, the command value of q-axis current i _q ^* is kept iq * _O.

As described above, the command value _iq ^* of the q-axis current does not change even if the current error slightly changes due to noise. Therefore, the control of the command value _id ^* of the d-axis current and the control of the command value _iq ^* of the q-axis current are not repeated.

When the reference value of the d-axis current is smaller than the reference value of the q-axis current, the same effect as a so-called play can be obtained, and stable control can be performed.

Ninth Embodiment Next, a ninth embodiment of the present invention will be described with reference to the drawings. The ninth embodiment is a control device capable of driving a synchronous motor even when an abnormality occurs in the above-described control device.

FIG. 17 is a block diagram of the ninth embodiment.

The ninth embodiment is different from the first embodiment in that the speed detection means, the first d-axis current command means 910, the second d-axis current command means 911, the abnormality detection means 960, the d-axis current selection means 962 is added and the d-axis current command means 110 is deleted. The same components as those in the first embodiment are denoted by the same reference numerals, and the description of the operation is omitted.

First, the first d-axis current command means 910
The same operation as the d-axis current command means 110 described in the first embodiment is performed to output a command value of the d-axis current. Also, the second
The d-axis current command means 911 of d
The same operation as the axis current command means 510 is performed to output a command value of the d-axis current. As described above, the ninth embodiment has two d-axis current command units. Abnormality detection means 910
Detects an abnormality of a circuit or operation and an abnormal part thereof. C
When the PU operation is abnormal, the synchronous motor 100 is operated with a fixed current phase (not shown in the figure, but in general, a fixed phase can be easily output by synchronizing with a position detection signal of the motor. is there). If only the integrator circuit for controlling is abnormal, the command value of the d-axis current given from the table obtained from the preset rotation speed and torque command current may be given (of course, the fixed current Phase operation). Normally, the d-axis current selection means 962 selects the d-axis command value output from the first d-axis current command means 910 that performs feedback control. However, when the abnormality is detected by the abnormality detection unit 960, the d-axis current selection unit 962 selects the d-axis command value output from the second d-axis current command unit 911.

The abnormality detected by the abnormality detecting means 910 includes an abnormality of the sensor (current detecting means 102 and speed detecting means 254).

As described above, even when an abnormality occurs, the d-axis current command can be issued, and the synchronous motor 100 can continue to operate.

It should be noted that the abnormal operation detecting means 960 may be constituted by a switch or the like merely for switching the control operation, and may be used as a switching means for switching to the table control when a basic operation other than the control is to be checked at the time of shipment. .

The individual embodiments have been described so far in the case where individual means are added. Here, it is needless to say that the combined effect can be obtained by combining these respective means.

In the above-described embodiment, it has been described that a current flows through the stator of the synchronous motor. What is a synchronous motor stator?
It means a winding of a synchronous motor that generates a rotating magnetic field when an alternating current is applied. For example, when the permanent magnet is fixed and does not move, the stator of the synchronous motor is an armature.

[0280]

According to the present invention, at least the following effects can be obtained.

Since the d-axis current command means adjusts the d-axis current command value to an optimum value according to the motion state of the synchronous motor, the synchronous motor can be operated with high efficiency even if a characteristic change such as a temporal change or an environmental change occurs. It is possible to do. Further, since the current initial value output means has the initial value of the d-axis current command value set in a table or the like, the time required for the d-axis current command value to converge on the target d-axis current command value is reduced.
Further, the power running / regeneration judging means detects the power running or the regenerative state of the synchronous motor, so that an optimal d-axis current can be given in the power running and the regeneration. By measuring the power supply voltage supplied to the synchronous motor by the voltage measuring means, the synchronous motor can be controlled without using feedback control. Furthermore, when the power supply is formed of a battery or the like, an appropriate d-axis current command value can be generated even if the voltage of the power supply drops.

Also, various driving modes are possible by determining the driving conditions of the efficiency-oriented and the torque-oriented operations and switching the reference value according to each operating condition. In addition, since the d-axis current and the q-axis current can be controlled separately, the responsiveness of the d-axis current command value and the responsiveness of the q-axis current command value can be improved.

Even if an abnormality occurs in a circuit or system for performing feedback control, since the second d-axis current command means commands the d-axis current based on a predetermined value, the synchronous motor Can be controlled.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a control device for a permanent magnet synchronous motor of the present invention.
FIG. 3 is a block diagram showing a configuration of an example of FIG.

FIGS. 2A to 2C are vector diagrams for explaining field-weakening control during power running.

3A is a diagram showing a proportional integrator, and FIGS.
(c) is a diagram showing a phase current command value input to the proportional integrator and an actual phase current.

FIG. 4 is a detailed view of a current applying unit.

FIG. 5 is a diagram showing a PWM signal when the signal is saturated and when it is not.

FIGS. 6A and 6B are diagrams of a non-salient pole motor rotor and a reverse salient pole motor rotor.

FIG. 7 is a block diagram illustrating a configuration of a control device according to a second embodiment of the present invention.

FIG. 8 is a block diagram illustrating a configuration of a control device according to a third embodiment of the present invention.

FIGS. 9A to 9C are vector diagrams for explaining field-weakening control during regeneration.

FIG. 10 is a block diagram illustrating a configuration of a control device according to a fourth embodiment of the present invention.

FIG. 11 is a block diagram illustrating a configuration of a control device according to a fifth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of a control device according to a sixth embodiment of the present invention.

FIG. 13 is a block diagram illustrating a configuration of a control device according to a seventh embodiment of the present invention.

FIG. 14 is a diagram showing an area for automatic switching between an efficiency-oriented setting and a torque-oriented setting in a field weakening region.

FIGS. 15A to 15C are operation range diagrams of automatic switching between the efficiency-oriented setting and the torque-oriented setting.

FIG. 16 is a block diagram illustrating a configuration of a control device according to an eighth embodiment of the present invention.

FIG. 17 is a block diagram illustrating a configuration of a control device according to a ninth embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 Synchronous motor 102 Current detection means 104 Saturation degree output means 106 Judgment value output means 108, 208, 708 Reference output means 110, 210, 310, 510, 810 d-axis current command means 130, 230, 530, 830 q-axis current command Means 136 Current command means 138 Input application means 250 Change timing output means 252 d-axis current change means 254 Speed detection means 256 d-axis current update means 340 Current initial value output means 370 q-axis current change amount means 420 Power running regeneration judgment means 422 Change Ratio output means 640 Voltage measurement means 642 d-axis current maximum value output means 750 Operating condition determination means 806 d-axis judgment value output means 807 q-axis judgment value output means 808 d-axis reference output means 809 q-axis reference output means 831 q-axis current Change means 910 first d-axis current command Stage 911 second d-axis current command unit 960 abnormality detecting means 962 d-axis current selection means

Continuation of front page (72) Inventor Satoshi Tamaki 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-62-7396 (JP, A) JP-A-61-22795 (JP, A) JP-A-5-30774 (JP, A) JP-A-7-107772 (JP, A) JP-A-5-199785 (JP, A) 3-1555387 (JP, A) Hira 6-21394 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02P 5/408-5/412 H02P 7/628-7 / 632 H02P 21/00 H02P 6/00-6/24 H02M 7/42-7/98 B60L 1/00-3/12 B60L 7/00-13/00 B60L 15/00-15/42

Claims (32)

(57) [Claims] 1. A current command for outputting a stator phase current command value calculated from a command value of a d-axis current as a direct axis stator current and a command value of a q-axis current as a horizontal axis stator current. Means, input application means for supplying a current to each phase based on each phase current command value, and saturation output means for generating a saturation indicating a rate at which the input application means can further supply a current to each phase. Reference output means for outputting a reference value of the degree of saturation; judgment value output means for calculating a judgment value obtained by subtracting the reference value of the degree of saturation from the degree of saturation; and when the judgment value is positive, the current phase is advanced. If the judgment value is negative, the command value of the d-axis current is decreased, and the command value of the decreased d-axis current is set. When the d-axis current command value is kept at the minimum value when the d-axis current command value is decreased beyond the set minimum value, Means, controller for a permanent magnet synchronous motor and a q-axis current command means for giving a command value of the q-axis current. 2. The saturation level output means generates the saturation level based on a difference between a phase current command value of the at least one stator and a phase current value of the permanent magnet synchronous motor. 2. The control device for a permanent magnet synchronous motor according to claim 1. 3. The saturation degree output means calculates the saturation degree based on a value obtained by integrating a difference between a command value of the q-axis current and a value of a q-axis current flowing through a stator of the permanent magnet synchronous motor. The control device for a permanent magnet synchronous motor according to claim 1, wherein the control device generates the control signal. 4. The saturation output means includes an integrator for integrating the difference, and the controller has a changeable element for adjusting a rate at which the integrator integrates. Item 4. A control device for a permanent magnet synchronous motor according to item 3. 5. A method according to claim 1, wherein said saturation output means calculates a difference between a torque command value calculated based on at least one current command value and an actual torque of said permanent magnet synchronous motor.
The control device for a permanent magnet synchronous motor according to claim 1, wherein the saturation degree is generated. 6. A method according to claim 1, wherein said saturation output means calculates a value obtained by integrating at least one phase current command value and a value obtained by integrating a detected value of said phase current flowing through a stator of said permanent magnet synchronous motor. The method according to claim 1, wherein the saturation is generated based on a difference.
A control device for a permanent magnet synchronous motor as described in the above. 7. When the judgment value is positive, the d-axis current command means increases the command value of the d-axis current, and the command value of the increased d-axis current becomes larger than a preset maximum value. When larger, the d-axis current command means sets the command value of the d-axis current to the preset maximum value, and when the judgment value is negative, the d-axis current command means sets the d-axis current When the command value of the reduced d-axis current is smaller than a preset d-axis minimum value, the d-axis current command means reduces the command value of the d-axis current to the preset minimum value. The control device for a permanent magnet synchronous motor according to claim 1, wherein the control device is set to a value. 8. The d-axis current command means increases the command value of the d-axis current when the judgment value is positive, and changes the command value of the d-axis current when the judgment value is negative. Decrease
When the command value of the decreased d-axis current is smaller than a preset d-axis minimum value, the command value of the d-axis current is set to the preset minimum value; , created based on the values and rate command value and the vector subtraction of the d-axis current from the pre-set maximum value of the command value and the synthetic current value vector sum of the command value and the q-axis current of the d-axis current 2. The control device for a permanent magnet synchronous motor according to claim 1, wherein a smaller value among the command values of the q-axis current is set as the command value of the q-axis current. 3. 9. The control device, wherein the control device detects a rotation speed of the permanent magnet synchronous motor, and wherein the command value of the d-axis current is a value within a certain range for a certain period, If the speed is within a certain range,
Change timing output means for forcibly outputting the timing of changing the command value of the d-axis current; and when the change timing is output, the command value of the d-axis current and the command value of the q-axis current are combined. D-axis current changing means for holding the combined current command value at a constant value and changing the command value of the d-axis current; and after the d-axis current changing means changes the command value of the d-axis current, When the rotation speed increases from the rotation speed before changing the command value of the d-axis current, an operation using the d-axis current command value after changing the command value of the d-axis current, and the rotation speed decreases. The d-axis current command value before changing the d-axis current command value.
And d-axis current updating means for repeating the operation using the axis current command value for a period permitted by the change timing output means, and updating the command value of the d-axis current. When the means changes the command value of the d-axis current, and the determination value is positive, the d-axis current updating means:
Changing the reference value of the reference output means to a newly calculated reference value, the d-axis current updating means changing a command value of the d-axis current, and if the determination value is negative, the d-axis The current updating means is d
Based on the value output from the d-axis current updating means to the axis current command means, set a minimum value of a preset d-axis current or a coefficient of an equation for calculating a command value of the d-axis current,
The control device for a permanent magnet synchronous motor according to claim 1. 10. A current initial value output means for outputting an initial command value of a d-axis current obtained from the q-axis current command value when the q-axis current command value greatly changes to a predetermined value or more. The control device for a permanent magnet synchronous motor according to claim 1, further comprising: 11. The control device further comprises a change rate output means for determining and outputting a change rate of the command value of the d-axis current, wherein the change rate output means comprises a predetermined constant change rate or The change value calculated from the judgment value and the command value of the d-axis current is output. If the judgment value is positive, the d-axis current command means converts the command value of the d-axis current based on the change ratio. When the command value of the d-axis current increases beyond a preset maximum value, the command value of the d-axis current is held at the preset maximum value, and the judgment value is negative. In this case, the command value of the d-axis current is decreased based on the rate of change, and when the command value of the d-axis current decreases beyond a preset minimum value, the command value of the d-axis current is decreased. 2. The control device for a permanent magnet synchronous motor according to claim 1, wherein the control device keeps the preset minimum value. Place. 12. The control device for a permanent magnet synchronous motor according to claim 11, wherein the change rate when the judgment value is positive is larger than the change rate when the judgment value is negative. 13. The control device further includes a powering regeneration judging means for judging whether the operation of the permanent magnet synchronous motor is in a powering state or a regenerative state, and wherein the change ratio output means is provided. And determining a rate at which the command value of the d-axis current is changed based on the determined state.
A control device for a permanent magnet synchronous motor as described in the above. 14. The permanent magnet synchronization according to claim 13 , wherein a rate of changing the command value of the d-axis current in the power running state is smaller than a rate of changing the command value of the d-axis current in the regenerative state. Motor control device. 15. The reference output means changes the reference value based on the output of the power running regeneration decision means, according to claim 13
A control device for a permanent magnet synchronous motor as described in the above. 16. The d-axis current command means, when the judgment value is positive, increases the command value of the d-axis current based on the rate of change, and exceeds the set maximum value. When the command value increases, the command value of the d-axis current holds the set maximum value, and when the judgment value is negative, the command value of the d-axis current decreases based on the change rate. When the command value of the d-axis current decreases beyond the set minimum value, the command value of the d-axis current is held at the minimum value, and the powering / regeneration determining means determines whether the driving state of the powering or the regeneration is A signal indicating a change is generated, and the command value of the d-axis current is changed from a previous command value of the d-axis current based on at least one of a rotation speed of the permanent magnet synchronous motor and a command value of the q-axis current. 14. The control device for a permanent magnet synchronous motor according to claim 13 . 17. The d-axis current command means for generating a reluctance torque generated according to a decrease in a torque command value when an allowable value of a braking torque of the permanent magnet synchronous motor is smaller than a predetermined value. In order to suppress a decrease in current, the command value of the d-axis current is not suddenly decreased,
The control device for a permanent magnet synchronous motor according to claim 13 . 18. A current command for outputting a command value of each phase current of the stator obtained from a command value of a d-axis current as a direct-axis stator current and a command value of a q-axis current as a horizontal-axis stator current. Means, input applying means for supplying a current to each phase based on the phase current command value, and whether the operation of the permanent magnet synchronous motor is power running or whether the operation of the permanent magnet synchronous motor is regenerative. Power running regeneration judging means for judging whether the state is regeneration, and when the rotation speed and torque of the permanent magnet synchronous motor do not belong to the field weakening region, the permanent magnet And d-axis current command means for outputting a command value of the d-axis current for generating a reluctance torque of zero or more power running in the synchronous motor; and q-axis current command means for giving a command value of the q-axis current. Control of permanent magnet synchronous motor Apparatus. 19. A current command for outputting a stator phase current command value calculated from a command value of a d-axis current which is a direct axis stator current and a command value of a q-axis current which is a horizontal axis stator current. Means, input applying means for supplying a current to each phase based on the phase current command value, and whether the operation of the permanent magnet synchronous motor is power running or whether the operation of the permanent magnet synchronous motor is regenerative. Power running regeneration judging means for judging the condition; d-axis current command means for giving a command value of the d-axis current when the power running regeneration judging means judges that the state is regeneration; and the d-axis current command is not zero. In this case, a control device for a permanent magnet synchronous motor, comprising: q-axis current command means for decreasing the command value of the q-axis current in accordance with the increase in the command value of the d-axis current, as much as the reluctance torque is generated. 20. A current command for outputting a stator phase current command value calculated from a command value of a d-axis current as a direct axis stator current and a command value of a q-axis current as a horizontal axis stator current. Means, input application means for supplying a current to each phase based on each phase current command value, and saturation output means for generating a saturation indicating a rate at which the input application means can further supply a current to each phase. A reference output means for outputting a reference value of the degree of saturation; a judgment value output means for outputting a judgment value obtained by subtracting the reference value of the degree of saturation from the degree of saturation; and a voltage applied to the inverter. Voltage measurement means for outputting a voltage value; d-axis current maximum value output means for outputting a maximum value of the command value of the d-axis current based on the measured voltage value; and d-axis if the judgment value is positive. The command value of the current is increased, and the command value of the increased d-axis current is When the value exceeds the large value, the command value of the d-axis current is held at the maximum value of the d-axis current, and when the judgment value is negative, the command value of the d-axis current is reduced, and the reduced d-axis current is reduced. D-axis current command means for holding the d-axis current command value at the minimum value when the current command value decreases below the set minimum value; and q-axis current for giving the q-axis current command value. A control device for a permanent magnet synchronous motor, comprising: command means. 21. The permanent magnet synchronous motor control according to claim 20 , wherein the d-axis current maximum value output means decreases the maximum value of the command value of the d-axis current when the measured voltage value decreases. apparatus. 22. A current command for outputting a stator phase current command value calculated from a command value of a d-axis current which is a direct axis stator current and a command value of a q-axis current which is a horizontal axis stator current. Means, an input applying means for supplying a current to each phase based on each phase current command value, a voltage measuring means for measuring a voltage applied to the permanent magnet synchronous motor and outputting the measured voltage value, A permanent magnet synchronous motor comprising: d-axis current command means for decreasing the maximum value of the d-axis current command value when the voltage value decreases, and q-axis current command means for giving the q-axis current command value. Control device. 23. A current for outputting a command value of each phase current of the stator calculated from a command value of a d-axis current which is a direct-axis stator current and a command value of a q-axis current which is a horizontal-axis stator current. Command means; input application means for supplying a current to each phase based on the phase current command value; and saturation output means for generating a saturation indicating a ratio at which the input application means can further supply a current to each phase. Operating condition determining means for outputting one of the operating conditions focusing on efficiency and operating condition focusing on torque; reference output means for outputting a reference value of saturation based on the operating condition; A judgment value output means for outputting a judgment value obtained by subtracting the reference value of the saturation from the reference value; and if the command value of the d-axis current is positive, the current phase is advanced and the judgment value becomes zero. D-axis current command means for increasing the command value of the d-axis current, Controller for a permanent magnet synchronous motor comprising: a q-axis current command means for giving a command value of q-axis current, a. 24. The permanent magnet synchronous motor according to claim 23 , wherein a reference value when said operating condition determining means outputs importance on efficiency is larger than a reference value when said operating condition determining means outputs importance on torque. Control device. 25. The reference output means, when at least one of the number of revolutions and the current of the permanent magnet synchronous motor exceeds a preset value, determines that the driving situation determining means attaches importance to the torque, and 24. The control device for a permanent magnet synchronous motor according to claim 23 , wherein the control device outputs a reference value smaller than the reference value in the case of emphasis. 26. A current command for outputting a stator phase current command value calculated from a command value of a d-axis current as a direct axis stator current and a command value of a q-axis current as a horizontal axis stator current. Means, input application means for supplying a current to each phase based on each phase current command value, and saturation output means for generating a saturation indicating a rate at which the input application means can further supply a current to each phase. Reference output means for outputting a reference value of the degree of saturation; reference output means for outputting a reference value; d-axis reference output means for outputting a d-axis reference value in accordance with the degree of saturation; Based on a value obtained by subtracting the d-axis reference value from the saturation,
d-axis determination value output means for outputting a d-axis determination value; q-axis determination value output means for outputting a q-axis determination value based on a value obtained by subtracting the q-axis reference value from the saturation degree processing value When the d-axis determination value is positive, the d-axis current command value is increased, and when the increased d-axis current command value exceeds a set maximum value, the d-axis current Is maintained at the set maximum value, and when the d-axis determination value is negative, the command value of the d-axis current is reduced, and the reduced d-axis current command value is set at the set minimum value. A d-axis current command means for holding the command value of the d-axis current at the set minimum value when the value is decreased beyond the value; a q-axis current command means for giving a command value of the q-axis current; If the axis determination value is positive and the command value of the d-axis current is the set maximum value, the q-axis commanded by the q-axis current command means The command value of the current is decreased, and the command value of the reduced q-axis current is set as a q-axis current change command value. The q-axis determination value is negative, and the command value of the d-axis current is the set maximum value. And the q-axis current change command value is q
A control device for a permanent magnet synchronous motor, comprising: q-axis current command changing means for increasing the command value of the q-axis current when the command value is not more than the command value of the q-axis current commanded by the shaft current command means. 27. The control device for a permanent magnet synchronous motor according to claim 26 , wherein the d-axis reference value output from the d-axis reference output means is smaller than the q-axis reference value output from the q-axis reference output means. . 28. A current command for outputting a stator phase current command value calculated from a command value of a d-axis current as a direct axis stator current and a command value of a q-axis current as a horizontal axis stator current Means, input application means for supplying a current to each phase based on each phase current command value, and saturation output means for generating a saturation indicating a rate at which the input application means can further supply a current to each phase. Operating condition determining means for outputting one of the operating conditions focusing on efficiency and operating condition focusing on torque; reference output means for outputting a reference value of saturation based on the operating condition; A judgment value output means for outputting a judgment value obtained by subtracting the reference value for the degree of saturation; and a first value for increasing the d-axis current command so that the current phase is advanced and the judgment value becomes zero when the judgment value is positive. Detects d-axis current command means and circuit or operation abnormalities Abnormality detection means and, said on the basis of the preset table or calculation formula d to
Second d-axis current command means for obtaining a command value for the axis current; q-axis current command means for providing a command value for the q-axis current; and first when the abnormality detection means does not detect a circuit or operation abnormality. The d-axis command value output from the second d-axis current command means is selected when the abnormality detection means detects a circuit or operation abnormality. A d-axis current selection means for selecting a value, a control device for a permanent magnet synchronous motor. 29. The apparatus according to claim 29, wherein the saturation output means is at least one.
The control device for a permanent magnet synchronous motor according to claim 1, wherein the saturation is generated based on a value obtained by integrating a difference between a phase current and a current command value of a phase corresponding to at least one phase. 30. The saturation output means further includes an integrator for integrating the difference, and the control device has a changeable element for adjusting a rate at which the integrator integrates. Item 30. The control device for a permanent magnet synchronous motor according to item 29 . 31. When the judgment value is positive, the d-axis current command means increases the command value of the d-axis current, and the command value of the increased d-axis current becomes larger than a preset maximum value. When larger, the d-axis current command means sets the command value of the d-axis current to the preset maximum value, and when the judgment value is negative, the d-axis current command means sets the d-axis current Decreasing the command value, when the rotation speed of the permanent magnet synchronous motor is equal to or less than a predetermined rotation speed, the d-axis current command means sets the command value of the d-axis current to a predetermined minimum value; The control device for a permanent magnet synchronous motor according to claim 1. 32. The permanent magnet synchronous motor according to claim 1, wherein the reference output means changes the reference value based on at least one of a current command value of each phase and a rotation speed of the permanent magnet synchronous motor. Control device.