JP2010239790A - Rotary electric machine controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce misjudgment when judging the demagnetization by a method using a V<SB>qc</SB>map in a rotary electric machine controller. <P>SOLUTION: A rotary electric machine controller 40 that controls a rotary electric machine 30 and a power supply circuit 10 connected thereto as a whole includes a section for performing vector control and a demagnetization decision block 60. The demagnetization decision block 60 is composed of a demagnetization decision processing unit 62 that decides the demagnetization of a permanent magnet on the basis of a d-axis current command value, a q-axis current command value, and a q-axis voltage command value, a current deviation decision processing unit 64 that determines that a current deviation is abnormal when a deviation between a current command value and an actual current value exceeds a preset threshold value for current deviation, and a change processing unit 66 that changes the demagnetization decision procedure for the permanent magnet to a decision on the basis of an actual d-axis current value, an actual q-axis current value, and the q-axis voltage command value when the current deviation is determined to be abnormal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine control device, and more particularly to a rotating electrical machine control device that determines demagnetization of a magnet in a rotating electrical machine having a permanent magnet.

  In a rotating electrical machine having a permanent magnet, demagnetization of the magnet may occur when a current exceeding a specified value is applied to the rotating electrical machine or due to temperature. When the demagnetization of the permanent magnet occurs, the performance of the rotating electrical machine deteriorates, so it is necessary to detect the demagnetization and take measures.

Therefore, Patent Document 1 states that the demagnetization of the permanent magnet is estimated based on the q-axis voltage manipulated variable in the control using the dq axis conversion of the permanent magnet motor as the motor driving device. Yes. Here, ω is the rotational angular velocity, φ is the armature flux linkage by the permanent magnet, L _d is the d-axis inductance, R is the armature resistance, I _d is the d-axis component of the armature current, and I _q is the armature current. As the q-axis component, the q-axis voltage V _q is expressed by V _q = ωφ−ωL _d I _d + RI _{q. When} demagnetization occurs, ωφ changes, and if I _d and I _q are the same, V _q Take advantage of the fact that changes occur. That is, the q-axis voltage manipulated _variable when no demagnetization occurs is mapped as V _qc in association with the torque corresponding to I _d and I _q and the motor rotational speed, and this V _qc and the actual V Compared with _q , it is determined that the _magnet is demagnetized when the actual V _q is smaller than V _qc .

  Further, in Patent Document 2, as a brushless DC motor abnormality detection device, the relationship between applied voltage, current, and rotation speed, rotor position detection abnormality and field magnetic field abnormality is stored as a map, and is reduced by comparison with actual measurement values. It is stated that a magnetic judgment is made.

  In Patent Document 3, as a demagnetization detection method for a permanent magnet motor, the rotational speed, current, and voltage are measured to estimate the winding temperature and winding resistance, and the magnet temperature is estimated from the winding temperature estimation. In addition, the normal value of the induced voltage is estimated, the actual value of the induced voltage is estimated from the winding resistance estimation, and the demagnetization of the permanent magnet is judged from this.

  Further, in Patent Document 4, as a demagnetization inspection of a permanent magnet of a brushless motor used in an inverter device, when an induced voltage of a rotating stator winding is integrated for a predetermined period, the integration result is obtained as follows: motor load, rotor It is stated that it can be determined whether or not the permanent magnet is demagnetized by comparing the integration result with the reference range because the value has a correlation with the amount of magnetic flux of the permanent magnet regardless of the rotational speed etc. Yes.

JP 2005-51892 A JP 2001-8488 A JP 2005-192325 A Japanese Patent Laid-Open No. 6-253581

As described above, various methods have been proposed for detecting the demagnetization of the permanent magnet provided in the rotating electrical machine. Here, in Patent Document 1, the q-axis voltage manipulated _variable when demagnetization does not occur is mapped as V _qc, and demagnetization is determined by comparing this V _qc with actual V _q. Is stated. This method is useful because it uses a _previously obtained map of V _qc . Map this method, when will be referred to as a process according to V _qc map, V _qc map, as shown in formula V _q, reading the V _qc by giving the rotational angular velocity and the d-axis current and the q-axis current It is.

In the vector control method using the d-axis current and the q-axis current, current feedback is performed so that the actual d-axis current value follows the d-axis current command value and the actual q-axis current value follows the q-axis current command value. Is called. Therefore, if the d-axis current is a d-axis current command value and a q-axis current command value, V _qc can be obtained from the required torque and the rotational speed of the rotating electrical machine, and demagnetization determination is facilitated.

  By the way, in the control of the rotating electrical machine, there may be a case where the actual d-axis current value does not become the same as the d-axis current command value, or the actual q-axis current does not become the same as the q-axis current command value. At this time, if the demagnetization determination is performed using the d-axis current command value and the q-axis current command value, an erroneous determination may occur. If erroneous demagnetization is determined, the rotor including the permanent magnet may be erroneously replaced at the time of repair.

An object of the present invention is to provide a rotating electrical machine control device capable of suppressing erroneous determination when determining demagnetization by a method using a V _qc map.

  The rotating electrical machine control device according to the present invention is a permanent magnet based on a d-axis current command value, a q-axis current command value, and a q-axis voltage command value in control using dq axis conversion of a rotating electrical machine having a permanent magnet. Demagnetizing determination means for determining the demagnetization of the motor, when the deviation between the d-axis current command value and the actual d-axis current value exceeds a preset d-axis current deviation threshold, or the q-axis current command value and the actual q-axis When the deviation from the current value exceeds a preset q-axis current deviation threshold, the current deviation determining means for determining that the current deviation is abnormal, and the demagnetizing determining means when determining that the current deviation is abnormal, Changing means for changing to determining demagnetization of the permanent magnet based on the shaft current value, the actual q-axis current value, and the q-axis voltage command value.

Further, in the rotating electrical machine control device according to the present invention, the demagnetization determining means includes ω as the rotational angular velocity, φ as the flux linkage by the permanent magnet, L _d as the d-axis inductance, R as the armature resistance, and I _d as the armature. The q-axis voltage V _q is expressed as V _q = ωφ−ωL _d I _d + RI _q , where _d is the d-axis component of the current, I _q is the q-axis component of the armature current, and ωφ changes when demagnetization occurs, It is preferable to determine the demagnetization of the permanent magnet by taking advantage of the change in V _q assuming that I _d and I _q are the same.

  With the above configuration, when the rotating electrical machine control device determines demagnetization of the permanent magnet based on the d-axis current command value, the q-axis current command value, and the q-axis voltage command value, the d-axis current command value and the actual d When the deviation from the axis current value exceeds a preset d-axis current deviation threshold, or when the deviation between the q-axis current command value and the actual q-axis current value exceeds a preset q-axis current deviation threshold, It changes to judging demagnetization of a permanent magnet based on an actual d-axis current value, an actual q-axis current value, and a q-axis voltage command value. Therefore, it is possible to reduce misjudgment regarding demagnetization that may occur when the current deviation is large.

Further, in the rotating electrical machine control device, the q-axis voltage V _q is expressed by V _q = ωφ−ωL _d I _d + RI _q , and it is used that a change in V _q occurs when demagnetization occurs. Since this method is the method described in Patent Document 1, it is possible to suppress erroneous determination in the method based on a proven demagnetization determination method.

It is a figure explaining the structure of the rotary electric machine control system containing the rotary electric machine control apparatus in embodiment which concerns on this invention. In an embodiment concerning the present invention, it is a figure explaining a principle of demagnetization judgment. It is an example of the Vqc map used in embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a figure explaining the description of the content of Vqc, and the example which may be misjudged when using a Vqc map. 4 is a flowchart illustrating a procedure for determining demagnetization in the embodiment according to the present invention. It is a time chart explaining the example which the misjudgment regarding a demagnetization arises in relation to embodiment which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a vehicle equipped with a rotating electrical machine will be described as an example where the rotating electrical machine control device is used. However, this is only an example, and any vehicle using a rotating electrical machine control device that performs vector control may be used.

  In addition, this vehicle will be described as using one motor / generator having a motor function and a generator function as a rotating electrical machine. However, this is an example, and two or more motors / generators are used. Also good. Alternatively, one rotating electrical machine having only a motor function and one rotating electrical machine having only a generator function may be used. In addition, as a vehicle, it is good also as what mounts an engine other than a rotary electric machine.

  Below, although the structure containing an electrical storage apparatus, a voltage converter, an inverter, and a smoothing capacitor is demonstrated as a power supply circuit connected to a rotary electric machine, this is an illustration, Comprising: You may include elements other than these. For example, a system main relay, a low voltage DC / DC converter, etc. can be included. In addition to the power storage device, a fuel cell may be included as a power source.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram showing the configuration of a rotating electrical machine control system 8 for a rotating electrical machine mounted on a vehicle. The rotating electrical machine control system 8 includes a rotating electrical machine 30, a power supply circuit 10 connected to the rotating electrical machine 30, and a rotating electrical machine control device 40 that controls the operation of these components as a whole. The rotating electrical machine control device 40 is an assembly of circuits having several control functions. Here, the rotating electrical machine control device 40 is shown mainly with respect to a portion that performs vector control, and has a function of performing a demagnetization determination in particular. The portion is shown as a demagnetization determination block 60.

  The rotating electrical machine 30 is a motor / generator (MG) mounted on a vehicle and functions as a motor when electric power is supplied from the power storage device 12 included in the power supply circuit 10 and is driven by an engine (not shown). Alternatively, it is a three-phase synchronous rotating electric machine that functions as a generator during braking of a vehicle. The rotating electrical machine 30 is a permanent magnet type rotating electrical machine in which a coil is wound around an armature that is a stator and a permanent magnet is provided on the rotor.

  The rotational position sensor 32 provided in the rotating electrical machine 30 has a function of detecting the rotational position of the rotor as the rotational angle θ. For example, a resolver can be used as the rotational position sensor 32. The data of the detected rotation angle θ is transmitted to the rotating electrical machine control device 40 through an appropriate signal line. In the rotating electrical machine control device 40, the rotation angle θ is used for vector control, and is converted into the angular velocity ω of the rotating electrical machine 30 from the time derivative of the rotation angle θ and used in the demagnetization determination block 60.

  The power supply circuit 10 is a circuit connected to the rotating electrical machine 30 and supplies power to the rotating electrical machine 30 when it functions as a drive motor, or receives regenerative power when the rotating electrical machine 30 functions as a generator. And has a function of charging the power storage device 12. The power supply circuit 10 includes a power storage device 12 that is a secondary battery, a smoothing capacitor 14 on the power storage device 12 side, a voltage converter 16, a smoothing capacitor 18 on the inverter 20 side, and an inverter 20.

  As the power storage device 12, for example, a lithium ion assembled battery or a nickel hydride assembled battery having a terminal voltage of about 200 V, a capacitor, or the like can be used.

  The voltage converter 16 is a circuit having a function of boosting the voltage on the power storage device 12 side to, for example, about 650 V using the energy storage action of the reactor, and is also called a boost converter. The voltage converter 16 has a bidirectional function, and when supplying electric power from the inverter 20 side as charging power to the power storage device 12 side, the high voltage on the inverter 20 side is lowered to a voltage suitable for the power storage device 12. Also have.

The smoothing capacitor 14 on the power storage device 12 side and the smoothing capacitor 18 on the inverter 20 side have a function of suppressing and smoothing fluctuations in voltage and current between the positive electrode bus and the negative electrode bus on the respective sides. The voltage V _H between the positive electrode bus and the negative electrode bus on the inverter 20 side is called a system voltage.

  The inverter 20 includes a plurality of switching elements that operate under the control of the rotating electrical machine control device 40, and is a circuit that performs power conversion between AC power and DC power. The inverter 20 converts the DC power from the power storage device 12 side into AC three-phase driving power when the vehicle is powering and supplies it as driving power to the rotating electrical machine 30, and conversely when the vehicle is braking. It has an AC / DC conversion function that converts AC three-phase regenerative power from the rotating electrical machine 30 into DC power and supplies it as a charging current to the power storage device 12 side.

The current flowing through each of the three wires connecting the inverter 20 and the rotating electrical machine 30 is detected as a current flowing through each phase of the rotating electrical machine 30 using an appropriate current detection sensor and transmitted to the rotating electrical machine control device 40. . Since each phase coil of the rotating electrical machine 30 is commonly connected at the neutral point, each phase current flowing through the rotating electrical machine is (U phase current value + V phase current value + W phase current value) = 0. Therefore, even if each of the three phase currents is not detected, two phase currents are detected, and the remaining phase currents can be obtained by calculation using the above relationship. In the example of FIG. 1, it is shown that the U-phase current I _u and the V-phase current I _v are detected, so the remaining W-phase current is obtained by calculation. The detected phase currents are transmitted to the rotating electrical machine control device 40 through appropriate signal lines. In the rotary electric machine control device 40, in vector control, first, it is converted into a d-axis current value I _d and a q-axis current value I _q , which is compared with the d-axis current command value I _d ^* and the q-axis current command value I _q ^*. And used for current feedback.

  The rotating electrical machine control device 40 has a function of controlling the operation of the rotating electrical machine 30 mounted on the vehicle as a whole through control of the power supply circuit 10 and the like. In particular, here, the operation of the rotating electrical machine 30 is controlled by vector control, and the function of determining the demagnetization of the permanent magnet of the rotating electrical machine 30 is provided. First, the part related to vector control will be described, and then the contents of the demagnetization determination block 60 will be described.

  The operation control of the rotating electrical machine 30 is switched between the rectangular wave mode, the overmodulation mode, and the sine wave PWM mode depending on the operating conditions of the rotating electrical machine 30. Here, a configuration for performing sine wave PWM control will be mainly described.

The part related to vector control is a part that performs current feedback control in sinusoidal PWM control. That is, in the sine wave PWM control mode, each phase current value of the rotating electrical machine 30 is converted into the d-axis current value I _d and the q-axis current value I _q in the three-phase two-phase coordinate conversion unit 42, while the torque command The d-axis current command value I _d ^* and the q-axis current command value I _q ^* are calculated from the value T ^* . Then, by feeding back the d-axis current value I _d to the d-axis current command value I _d ^*, q-axis current command value I _q ^* on the current feedback to feedback q-axis current value I _q is performed.

Here, the torque command value T ^* is calculated based on a user's requested torque obtained from a vehicle accelerator or the like (not shown). The current command generation unit 44 has a function of calculating the torque command value T ^* as a set of the d-axis current command value I _d ^* and the q-axis current command value I _q ^* using, for example, a table created in advance.

Subtractor 46 calculates the d-axis current deviation [Delta] I _d from the d-axis current command value I _d ^* by subtracting the d-axis current value I _d, the subtractor 48, a q-axis from the q-axis current command value I _q ^* It has a function of calculating a q-axis current deviation [Delta] I _q by subtracting the current value I _q.

The PI control unit 50 performs proportional-integral control on the d-axis current deviation ΔI _d and the q-axis current deviation ΔI _q under a predetermined gain to obtain a control deviation corresponding to these, and the d-axis corresponding to the control deviation The voltage command value V _d ^* and the q-axis voltage command value V _q ^* are calculated.

The two-phase / three-phase coordinate conversion unit 52 has a reverse conversion relationship with the previous three-phase / two-phase coordinate conversion unit 42 and has a function of converting a dq voltage value into each phase voltage value. That is, the function of converting the d-axis voltage command value V _d ^* and the q-axis voltage command value V _q ^* into the phase voltage command values V _u , V _v , V _w based on the rotation angle θ of the rotating electrical machine 30. Have. In these conversions, the system voltage V _H supplied from the voltage converter 16 to the inverter 20 is also reflected.

The PWM generation unit 54 has a function of generating a control signal for each switching element constituting the inverter 20 by comparing each phase voltage command value V _u , V _v , V _w with a carrier that is a predetermined carrier wave. The inverter 20 is a circuit that performs power conversion between AC power and DC power as described above. Since the inverter 20 includes six switching elements in the example of FIG. 1, six control signals are output from the PWM generator 54 to the inverter. 20 is supplied. Thereby, the PWM signal of each phase corresponding to each phase voltage command value is supplied to the rotating electrical machine 30.

The three-phase two-phase coordinate conversion unit 42 described above acquires two current values and a rotation angle θ among the respective phase currents of the rotating electrical machine 30, and the d-axis current value I _d and the q-axis based on the respective phase current values. It has a function of calculating the current value I _q . In the example of FIG. 1, coordinate conversion is performed based on the U-phase current value I _u and the V-phase current value I _v and the rotation angle θ of the rotating electrical machine 30.

Thus, in the sine wave PWM control mode, the actual current values I _d and I _{q of} the rotating electrical machine 30 are fed back to the current command values I _d ^* and I _q ^* corresponding to the torque command value T ^*. Control is performed.

  Now that the part related to vector control has been described, the contents of the demagnetization determination block 60 will be described next. The demagnetization determination block 60 has a function of determining whether or not demagnetization has occurred in the permanent magnet included in the rotating electrical machine 30 using a current value or the like used for vector control. Demagnetization is determined based on the following principle.

That is, ω is the rotational angular velocity, φ is the flux linkage by the permanent magnet, L _d is the d-axis inductance, R is the armature resistance, I _d is the d-axis component of the armature current, and I _q is the q-axis component of the armature current. The q-axis voltage V _q is expressed as V _q = ωφ−ωL _d I _d + RI _q . As can be seen from this equation, when demagnetization occurs, ωφ changes and I _d and I _q are the same, and V _q changes. Using this principle, the demagnetization of the permanent magnet is determined.

For example, with current value and voltage value as command values, I _d ^* is a d-axis current command value, I _q ^* is a q-axis current command value, and V _qc ^* is a q-axis voltage command value when no demagnetization occurs. Then, V _qc ^* = _ωφ −ωL _d I _d ^* + RI _q ^* . Now, assuming that demagnetization occurs in the permanent magnet and the interlinkage magnetic flux becomes φ ′, and the q-axis voltage command value when the same I _d ^* , I _q ^*, and ω are given is V _q ^* , V _q ^* = ωφ′−ωL _d I _d ^* + RI _q ^* .

From this, the amount of demagnetization = φ−φ ′ = V _qc ^* −V _q ^* . Therefore, the amount of demagnetization can be obtained from a comparison between V _qc ^* and V _q ^* . This is shown in FIG. FIG. 2 shows the expression of V _q = ωφ−ωL _d I _d + RI _q as a vector. (A) is a state when demagnetization does not occur, and (b) is a state when demagnetization occurs. As shown here, under the same conditions of I _d ^* , I _q ^*, and ω, ΔV _q ^* = V _qc ^* −V _q ^* is generated corresponding to Δωφ = ωφ−ωφ ′.

Therefore, in order to perform demagnetization determination under the actual operating state of the rotating electrical machine 30, V _qc ^* in various operating states of the rotating electrical machine 30 is obtained and compared with V _q ^* in the actual operating state. do it. Various operating states are given by (I _d ^* , I _q ^* , ω), which is the same as the set of the torque command value T ^* and the rotational speed N of the rotating electrical machine 30. That is, V _qc ^* can be obtained and mapped in advance for various (T ^* , N) pairs and used. FIG. 3 is an example of such a map. Here, as a characteristic diagram of the rotating electrical machine 30, the horizontal axis represents the rotational speed N, and the vertical axis represents the torque command value T ^* .

By using the V _qc map in this way, V _qc ^* can be acquired under the (T ^* , N) operation state of the rotating electrical machine 30, so that the q-axis voltage command value when vector control feedback is being performed. By comparing V _q ^* and V _qc ^* , it can be determined that demagnetization has occurred when V _q ^* is smaller than V _qc ^* . In practice, it is preferable to set a demagnetization threshold value with an appropriate margin for V _qc ^* and determine that demagnetization occurs when V _q ^* is equal to or less than the demagnetization threshold value.

In this way, the demagnetization determination can be made using the V _qc map. However, V _q = ωφ−ωL _d I _d + RI _q is an expression indicating a physical phenomenon, and therefore, an actual current value, an actual voltage value, It is an equation that holds when the actual resistance value, the actual magnetic flux value, and the actual inductance value are satisfied. Thus, if a deviation occurs between the actual current value and the current command value, an erroneous determination may occur in the demagnetization determination. To some extent, misjudgment can be avoided by setting the margin of the demagnetization threshold, but if the current deviation between the actual current value and the current command value exceeds this margin, misjudgment may occur.

FIG. 4 shows that no demagnetization occurs, but when the actual current value differs from the current command value for some reason, the comparison between V _q ^* and V _qc ^* It is a figure explaining the example judged to be demagnetizing. (A) is the same as FIG. 2 (a) and is a state in which no demagnetization occurs. In (b), no demagnetization occurs, and the actual d-axis current value I _d is the same as the d-axis current command value I _d ^*. However, for some reason, the actual q-axis current value I _q is q-axis. This is a case where the current command value I _q ^* becomes smaller. The q-axis voltage command value V _q ^{* at} this time is smaller than V _qc ^* under the condition (I _d ^* , I _q ^* , ω). Therefore, it is determined that the magnetic field is demagnetized from the comparison between V _q ^* and V _qc ^* .

Similarly, FIG. 4C shows no demagnetization, and the actual q-axis current value I _q is the same as the q-axis current command value I _q ^* , but for some reason, the actual d-axis current value. This is a case where I _d becomes larger than the d-axis current command value I _d ^* . Also at this time, the q-axis voltage command value V _q ^* is smaller than V _qc ^* under the condition of (I _d ^* , I _q ^* , ω). Therefore, it is determined that the magnetic field is demagnetized from the comparison between V _q ^* and V _qc ^* .

As described above, if the current deviation, which is the difference between the current command value and the actual current value, is large, the method of comparing V _q ^* and V _qc ^* may cause an erroneous determination in the demagnetization determination.

Returning to FIG. 1 again, the demagnetization determination block 60 determines the demagnetization of the permanent magnet based on the d-axis current command value I _d ^* , the q-axis current command value I _q ^*, and the q-axis voltage command value V _q ^*. The demagnetization determination processing unit, the deviation between the d-axis current command value I _d ^* and the actual d-axis current value I _d exceeds a preset d-axis current deviation threshold, or the q-axis current command value I _q ^* When the deviation between the current q-axis current value I _q exceeds a preset q-axis current deviation threshold, the current deviation judgment processing unit judges that the current deviation is abnormal, and decreases when the current deviation is judged abnormal. In the magnetic field determination processing unit 62, a change processing unit that changes to determine the demagnetization of the permanent magnet based on the actual d-axis current value _Id , the actual q-axis current value _Iq, and the q-axis voltage command value _Vq ^*. 66.

  These functions can be realized by executing software, and specifically, can be realized by executing a rotating electrical machine demagnetization determination program. Some of these functions may be realized by hardware in some cases.

The V _qc map described in FIG. 3 is stored in an appropriate storage unit. As described above, the V _qc map shows the V-axis voltage command value V _qc ^* when no demagnetization occurs under the conditions (I _d ^* , I _q ^* , ω). It is also possible to store in an expression format other than. For example, (I _d ^* , I _q ^* , ω) may be given and stored in a lookup table format from which V _qc ^* can be read. Further, it may be stored in the form of a calculation formula that inputs (I _d ^* , I _q ^* , ω) and outputs V _qc ^* so that it can be searched.

  The operation of the demagnetization determination block 60 will be described with reference to the flowchart of FIG. FIG. 5 is a flowchart showing a procedure for determining the demagnetization of the permanent magnet of the rotating electrical machine. Each of these procedures corresponds to each processing procedure in the rotating electrical machine demagnetization determination program.

First, the current command value and the actual current value under the operating conditions of the rotating electrical machine 30 are acquired (S10). The current command values I _d ^* and I _q ^* are obtained from the output of the current command generator 44 in FIG. The actual current values I _d and I _q are acquired from the output of the three-phase two-phase coordinate conversion unit 42. Then, the current deviation is compared with a predetermined deviation threshold value to determine whether the current deviation is normal or abnormal (S12). This determination is made for each of the d-axis current and the q-axis current. That is, when the deviation between the d-axis current command value I _d ^* and the actual d-axis current value I _d exceeds a preset d-axis current deviation threshold, or the q-axis current command value I _q ^* and the actual q-axis current value When the deviation from I _q exceeds a preset q-axis current deviation threshold, it is determined that the current deviation is not normal but abnormal.

When it is determined in S12 that the current deviation is normal, V _qc ^* is read from (I _d ^* , I _q ^* , ω) as _usual , and this V _qc ^* and q-axis voltage command value V are read. _A demagnetization determination is made by comparison with _q ^* (S14). As the q-axis voltage command value V _q ^* , the output value of the PI control unit 50 in FIG. 1 is used.

When it is determined in S12 that the current deviation is abnormally normal, I _d is used instead of I _d ^* , I _q is used instead of I _q ^*, and V _qc corresponding to this is _calculated from the map of FIG. ^* _Is read out, and demagnetization is determined by comparing this V _qc ^* with the q-axis voltage command value V _q ^* (S16). By doing in this way, the misjudgment about the demagnetization judgment when a current deviation is large can be avoided.

FIG. 6 is a diagram illustrating an example in which an erroneous determination occurs regarding the demagnetization determination. In FIG. 6, the horizontal axis represents time, and the vertical axis represents demagnetization detection signals, I _d , I _d ^* , I _q , I _q ^* , V _qc ^* , demagnetization thresholds V _qcth , V _q ^* , and system voltage V _H. The mode switching signal is sequentially taken. FIG. 6 shows that I _d ^* = I _q ^* = 0 when the system voltage V _H = about 240 V and the fixed control in the sine wave PWM mode is being performed, that is, when the rectangular wave mode control is prohibited due to some failure. The situation when trying is shown.

Here, ω is a certain value, and V _qc ^* = about 460 V under the condition of I _d ^* = I _q ^* = 0. On the other hand, the maximum voltage that can be output in the sinusoidal PWM mode with V _H = 240V is 240V × 0.707 = about 170V, which is the maximum value of V _q ^* . Therefore, V _q ^* is smaller than V _qc ^* , and erroneous determination is made in the demagnetization determination.

This corresponds to the case where RI _q ^* = RI _q = 0 and ωL _d I _d is not zero in FIG. 4C, and the non-zero I _d becomes d-axis current command value I _d ^* = 0. However, it means that it is flowing, and the current deviation is abnormal.

In such a case, if V _qc ^* is compared with V _q ^* not by I _d ^* but by V _qc ^* using I _d , FIG. 4 (a) and FIG. 4 (c) are compared. As can be seen, V _qc ^* also becomes smaller, V _q ^* becomes the same as V _qc ^*, and erroneous determination of demagnetization determination can be avoided.

  The rotating electrical machine control device according to the present invention can be used in a control device that performs demagnetization determination of a permanent magnet in a rotating electrical machine having a permanent magnet.

  8 rotating electrical machine control system, 10 power supply circuit, 12 power storage device, 14, 18 smoothing capacitor, 16 voltage converter, 20 inverter, 30 rotating electrical machine, 32 rotational position sensor, 40 rotating electrical machine control device, 42 3-phase 2-phase coordinate conversion Unit, 44 current command generation unit, 46, 48 subtractor, 50 PI control unit, 52 3-phase 2-phase coordinate conversion unit, 54 PWM generation unit, 60 demagnetization determination block, 62 demagnetization determination processing unit, 64 current deviation determination Processing unit, 66 Change processing unit.

Claims (2)

Demagnetizing determination means for determining demagnetization of a permanent magnet based on a d-axis current command value, a q-axis current command value, and a q-axis voltage command value in control using dq axis conversion of a rotating electrical machine having a permanent magnet When,
When the deviation between the d-axis current command value and the actual d-axis current value exceeds a preset d-axis current deviation threshold, or when the deviation between the q-axis current command value and the actual q-axis current value is set in advance A current deviation judging means for judging that the current deviation is abnormal when the current deviation threshold is exceeded;
Change to change to determining demagnetization of permanent magnet based on actual d-axis current value, actual q-axis current value, and q-axis voltage command value in demagnetization determining means when current deviation abnormality is determined Means,
A rotating electrical machine control device comprising: In the rotating electrical machine control device according to claim 1,
The demagnetization judgment means is
ω is the rotational angular velocity, φ is the flux linkage by the permanent magnet, L _d is the d-axis inductance, R is the armature resistance, I _d is the d-axis component of the armature current, and I _q is the q-axis component of the armature current, The q-axis voltage V _q is expressed by V _q = ωφ−ωL _d I _d + RI _q , and when demagnetization occurs, ωφ changes, and I _d and I _q are the same, and the change in V _q occurs. And determining the demagnetization of the permanent magnet.

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