JPH07245969A - Power converter - Google Patents

Abstract

PURPOSE:To prevent failure, in which a large number of ripples are generated in a DC circuit, and to continue operation safely by forming chopper currents in an irregular waveform by controlling PWM carrier phase so that the relationship of phase difference among each group of resistance chopper devices consisting of a plurality of groups is brought to 360 deg./operation groups at all times. CONSTITUTION:Group start-stop signals are input in PWM carrier generating circuits, in which the failure of chopper converters is generated, and the phase correction signals of each group of each PWM carrier generating circuit are output by a carrier phase correction circuit 28. A signal, which advances at 60 deg. from a phase shifting data and phase of which is shifted, is output from the carrier phase correction circuit 28 in the PWM carrier generating circuit 23, and input to a bit counter 25 by a phase reference signal at 180 deg. and an arithmetic circuit 42 through a changeover switch 41. According to such operation, a power converter is operated by phase shifting relationship, in which carrier signals are shifted at 120 deg. respectively, from phase shifting relationship, in which the carrier signals are shifted at 90 deg. respectively, in the PWM carrier generating circuits.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion device which uses a forward conversion device and is provided with a multi-group resistance chopper device on the DC output side to supply electric power to a load such as a linear motor.

[0002]

2. Description of the Related Art FIG. 6 shows the configuration of a main circuit of a conventional power converter. A forward conversion device 3 that converts direct current power from the alternating current power system 1 through a forward converter transformer 2 is connected, and a DC reactor 4 that reduces ripples is connected in series to the output side of the forward conversion device 3 and a direct current is supplied. A chopper device 5 that consumes electric power is connected. The chopper device 5 includes a chopper conversion device 50 including a semiconductor switch and a resistor 6
0s are connected in series.

A power capacitor 7 for a voltage type inverter connected to a DC system and an inverter conversion device 8 capable of forward / reverse conversion operation are connected in parallel to the chopper device 5, respectively, and an inverter conversion is performed on the output side of the inverter conversion device 8. The load system 10 is connected via the transformer 9 for electric power, and electric power is supplied to the load system 10 by this.

FIG. 7 shows an example of the configuration of the chopper device 5. The direct current circuit of the forward conversion device 3 has a 4-group parallel configuration.
Resistors 61, 62, 63 and 64 are connected in series to the chopper converters 51, 52, 53 and 54.

In such a power converter, the PWM gate control circuit of the chopper device 5 is constructed as shown in FIG. The output signals of the oscillator 20 are converted into PWM carrier generation circuits (1) 21, (2) 22, (3) 23,
(4) Input to 24, output the phase reference value signal determined here, and this phase reference value signal generates carrier signals of the respective phase differences to generate comparison circuits (1) 29, (2) 30, (3 )
31 and (4) 32, the gate pulse signal is output by comparing with a control signal from a control circuit (not shown).

The gate pulse signal becomes an input signal to the AND (logical product) circuits (1) 33, (2) 34, (3) 35, and (4) 36, and the gate pulse O is used as another condition signal.
An N / OFF condition signal is used as an integrated signal such as a driving, stopping, or failure signal, and a "1" signal level is input to the driving group.

FIG. 9 is a block diagram showing an example of the PWM carrier generation circuit 21, which is a bit counter 25 for inputting an output signal from the oscillator 20 and a phase reference signal.
And a PWM signal generation circuit 26 that generates a PWM signal by the output of the bit counter 25.

The operation of such a PWM gate control circuit will be described. Main circuit configuration is 4 groups, so each PWM
The relationship between the phase differences of the carrier generation circuits 21 to 24 is 360
The phase reference signals in the PWM carrier generation circuits 21 to 24 are given so that ° / 4 = 90 °, and the waveforms are as shown in FIG. 2. The PWM1 output waveform in the figure is the output of the PWM carrier generation circuit 21. Correspondingly, the PWM2 output waveform corresponds to the output of the PWM carrier generation circuit 22, and PW
The M3 output waveform corresponds to the output of the PWM carrier generation circuit 23, and the PWM4 output waveform corresponds to the output of the PMW carrier generation circuit 24. Here, a gate pulse is generated at each timing by comparison with the control signal.

[0009]

With the above configuration, when the first group fails during the fourth group operation, the gate pulse of the target group is turned ON / O.
The signal level of the FF condition signal becomes "0", the gate pulse is not generated, and the remaining three group operation is performed.

At this time, in the conventional PWM gate control circuit in which the phase reference signal shown in FIG. 9 is fixed, if the carrier phase is not controlled, the chopper current becomes an irregular waveform and many ripples occur in the DC circuit. Occurs.

Although only the PWM carrier generation circuit 21 is shown in FIG. 2, the values of the phase reference signals are different from 0 °, 90 °, 180 °, and 270 °, respectively, and other circuits are omitted. ing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power conversion device which can be operated stably without the problem that the chopper current has an irregular waveform and many ripples occur in the DC circuit. .

[0013]

In order to achieve the above object, according to the invention corresponding to claim 1, a forward converter for converting AC power into DC power and a DC output side of the forward converter are provided. A power conversion device configured to include a plurality of groups of resistance chopper devices that consume direct current power through resistors connected through semiconductor switches and an inverter conversion device that is connected to a direct current system and is capable of forward-reverse conversion operation, and that supplies power to a load. At
The failure group of the resistance chopper device stops the gate block, the sound group of the resistance chopper device continues to operate, and in advance by the detection signal of the operation group of the resistance chopper device or the stop group of the resistance chopper device, Phase signal setting means for setting the set carrier phase signal, switching timing control means for constantly setting the phase difference of the carrier phase signals to 360 ° / operation group, and phase shift carrier phase signal of the switching timing control means And a gate pulse signal generating means for operating the resistance chopper device with a gate pulse signal obtained from the signal.

In order to achieve the above object, according to the invention corresponding to claim 2, in the power converter according to claim 1, when the number of operating groups of the resistance chopper device changes,
It is a power conversion device characterized in that, when a carrier phase signal in operation is changed to a phase shift carrier phase signal, the value is made the same as the phase difference value of the carrier phase signal before the temporary change.

In order to achieve the above object, according to the invention corresponding to claim 3, in the power converter according to claim 1, when the number of operation groups of the resistance chopper device changes,
It is an electric power conversion device characterized in that when a carrier phase signal in operation is changed to a phase shift carrier phase signal, it is performed by instantaneously shifting to the changed phase.

In order to achieve the above object, according to the invention corresponding to claim 4, in the power converter according to claim 1, the phase shift timing of the carrier phase signal is set to a change time point of the operation group of the resistance chopper device. Therefore, the value of the phase signal is shifted at the same time.

In order to achieve the above-mentioned object, according to the invention corresponding to claim 5, in the power converter according to claim 1, the phase shift timing of the carrier phase signal is set to the change time point of the operation group of the resistance chopper device. From the phase lead group, the value of the phase signal is phase-shifted.

[0018]

According to the inventions corresponding to claims 1 to 5,
Since the PWM carrier phase is controlled so that the phase difference between the groups of the resistance chopper device consisting of a plurality of groups is always 360 ° / operating group, the chopper current becomes an irregular waveform and ripples in the DC circuit. It is possible to provide a power conversion device that is capable of stable and continuous operation without causing many problems.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing only a PWM carrier generation circuit of a resistance chopper device according to a first embodiment of the present invention. What is different from the conventional example of FIG. 9 is that an arithmetic circuit 42 is provided for a phase reference signal, The calculation is performed via the changeover switch 41 that switches the output of the correction circuit 28.

The changeover switch 41 is turned on and off according to the output signal of the changeover timing selection circuit 27. The output of the oscillator 20 is input to the bit counter 25 via the changeover switch 40.

The changeover switch 40 is turned on and off according to the output signal of the changeover timing selection circuit 27. PW of the resistance chopper device configured as described above
Regarding the operation of the M control circuit, the operation when the first group is stopped from the fourth group operation will be described from the third group operation to the first group additional startup.

Regarding the operation of the PWM control circuit in the normal operation state, there is a phase shift relationship in which the carrier signal and the control signal from the control circuit (not shown) shown in FIG. Two
The output waveforms of 3, 24 are shown by PWM 1, 2, 3, 4 outputs in the figure.

The comparison circuit 2 uses the output waveform and the control signal.
Gate pulses 1 to 4 as outputs of 9, 30, 31, 32
Is obtained and input to the AND circuits 33, 34, 35 and 36.

In the AND circuits 33, 34, 35 and 36, a gate pulse is transmitted to the main body device (not shown) to control the regeneration of DC power according to the operation / stop failure stop signal condition.

Regarding the operation when stopping due to a failure of the chopper converter 52 shown in FIG. 7 during such operation,
The PWM carrier generation circuit and the operation time chart will be described with reference to FIG.

Further, FIG. 4 shows the phase shift data when the chopper converter 52 is out of order as an example of the relationship of the carrier phase, and each phase shift data at the time of group stop is input to the carrier phase correction circuit 28 and the phase correction amount. Is output.

Operation Time Chart At point P in FIG. 3, a failure of the chopper converter 52 occurs and the gate pulse 2 is blocked. At this time, the group start and stop signals are input to the PWM carrier generation circuit in FIG. 1, and the phase correction signals of the respective groups are output by the carrier phase correction circuit 28 in each PWM carrier generation circuit.

In the PWM carrier generation circuit 21,
As long as the chopper converter 51 does not break down, the carrier signal is used as the reference phase, and therefore the phase correction signal is not output. The PWM carrier generation circuit 22 does not output the phase correction signal because it is a failure group.

In the PWM carrier generation circuit 23,
A signal that leads the phase shift data by 60 ° and shifts the phase is output from the carrier phase correction circuit 28, and is input to the bit counter 25 by the phase reference signal of 180 ° via the changeover switch 41 and the arithmetic circuit 42.

On the other hand, in the changeover timing selection circuit 27, due to the lead phase shift failure group, the changeover switch 4
0 remains turned on, and the changeover switch 41 is
It is turned on at the same time as the stop group signal and the phase is corrected.

Similarly, in the PWM carrier generation circuit 24, a signal that leads the phase shift data by 60 ° and shifts the phase is output from the carrier phase correction circuit 28, and the phase reference signal of 270 ° and the arithmetic circuit via the changeover switch 41. 42 is input to the bit counter 25.

On the other hand, in the changeover timing selection circuit 27, due to the lead phase shift failure group, the changeover switch 4
0 remains turned on, and the changeover switch 41 is
It is turned on at the same time as the stop group signal to correct the phase.

By operating in this way, the PWM carrier generating circuit operates in a phase shift relationship in which the carrier signals are shifted by 90 ° from each other and shifted by 120 ° in each.

Next, the operation when the chopper converter 52 shown in FIG. 7 is additionally activated will be described with reference to the PWM carrier generation circuit and the operation time chart of FIG. At the point Q in FIG. 5, the chopper converter 52 starts up,
Gate pulse 2 is deblocking.

At this time, the group activation signal is input to the PWM carrier generation circuits 21 to 24 in FIG. 1, and the carrier phase correction circuit 28 causes the phase correction signals of the respective groups in the PWM carrier generation circuits 21 to 24. Is output.

In the PWM carrier generation circuit 21,
Since the reference phase of the chopper converter 51 is used, the phase correction signal is not output. The PWM carrier generation circuit 22 does not output the phase correction signal because the whole group operation is performed.

In the PWM carrier generation circuit 23,
A signal that is delayed by 60 ° from the phase shift data is output from the carrier phase correction circuit 28, and is input to the bit counter 25 by the phase reference signal of 180 ° via the changeover switch 41 and the arithmetic circuit 42.

On the other hand, in the changeover timing selection circuit 27, the changeover switch (SW
1) 40 is temporarily opened to stop the updating of the counter, the value of the previous value is held, the changeover switch 40 is turned on after the time of the phase shift data of 60 °, and the updating of the bit counter 25 is started.

The changeover switch (SW2) 41 is turned on at the same time as the group activation signal to correct the phase. Similarly, PW
In the M carrier generation circuit 24, 6 is obtained from the phase shift data.
A signal phase-shifted by a delay of 0 ° is output from the carrier phase correction circuit 28, and the phase reference signal of 270 ° via the changeover switch 41 and the bit counter 25 by the arithmetic circuit 42.
Are typing in.

On the other hand, in the switching timing selection circuit 27, because of the delayed phase shift group, the changeover switch 40 is temporarily opened to stop the updating of the counter, and the previous value is held, and the phase shift data is timed by 60 °. After that, the changeover switch 40 is turned on to start updating the counter.

The changeover switch 41 is turned on at the same time as the group start signal to correct the phase. By operating in this manner, the PWM carrier generation circuits 21 to 24 are operated in a phase shift relationship in which the carrier signals are shifted by 120 ° from a phase shift relationship in which the carrier signals are shifted by 90 °.

According to the above-described embodiment, the operation can be performed so that the carry chopper current does not have an irregular waveform even when the chopper device is stopped and started. That is, when one of the four groups of the resistance chopper device is stopped due to a failure, a phase signal setting means for setting a carrier phase signal set in advance by a group start / stop signal and a failure group of the resistance chopper device. The switching timing selection circuit 27 that switches the carrier phase signal by the switching timing selection circuit 27 gates the failure group and continues the operation of the healthy group, and the group addition start signal when the first group is additionally activated during the third group operation. Thus, the additional group is configured to be gate-deblocked by means for setting the carrier phase signal set in advance and means for switching the carrier phase signal by the switching timing selection circuit 27 by the additional starting group.

The resistance chopper device of the present invention described above is
Even when the group is stopped or started, the carrier phase signal switching circuit and the means for switching the carrier phase signal by the timing selection circuit can operate so that the chopper current does not have an irregular waveform.

In this embodiment, the phase shift timing is changed at the same time. However, the phase shift timing may be changed from the group with the advanced phase of the chopper converter group, and the phase shift timing is processed as data. It can also be achieved with easy maximum, minimum, and intermediate timings.

[0045]

According to the present invention, when the carrier phase signal is switched at the time of stopping and starting the group, the chopper current is always operated at a phase difference of 360 ° / operating group depending on the number of operating groups. A converter can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a PWM carrier generation circuit of a first embodiment of a resistance chopper device according to the present invention.

FIG. 2 is a diagram for explaining an operating state of a PWM gate pulse during all-group operation.

FIG. 3 is a diagram for explaining an operation state of a PWM gate pulse operation from a fourth group operation to a third group operation.

FIG. 4 is a diagram showing a vector relationship of carrier phases.

FIG. 5 is a diagram for explaining an operation state of a PWM gate pulse operation from a third group operation to a fourth group operation.

FIG. 6 is a circuit diagram showing an example of a conventional power conversion device.

7 is a diagram showing a configuration of the resistance chopper device of FIG.

8 is a block diagram showing the PWM gate pulse generation circuit of FIG.

9 is a block diagram showing the PWM carrier generation circuit of FIG. 8. FIG.

[Explanation of symbols]

1 ... AC power system, 2 ... Transformer for forward converter, 3 ... Forward converter, 4 ... DC reactor, 5 ... Chopper device, 50,
51, 52, 53, 54 ... Chopper conversion device, 60, 6
1, 62, 63, 64 ... Resistors, 7 ... Power capacitors,
8 ... Inverter conversion device, 9 ... Inverter transformer, 10 ... Load system, 20 ... Oscillator, 21 ... PWM carrier generation circuit 1, 22 ... PWM carrier generation circuit 2, 2
3 ... PWM carrier generation circuit 3, 24 ... PWM carrier generation circuit 4, 25 ... Bit counter, 26 ... PWM signal generation circuit, 27 ... Switching timing selection circuit, 28
... Carrier phase correction circuit, 29, 30, 31, 32 ... Comparison circuits (1) to (4), 33, 34, 35, 36 ... AN
D circuits (1) to (4), 40, 41 ... Changeover switch, 42 ... Operation circuit.

Claims (5)

[Claims] 1. A forward converter for converting alternating current power to direct current power, and a plurality of groups of resistance chopper devices for consuming direct current power on a direct current output side of the forward converter by a resistor connected via a semiconductor switch, In a power conversion device that is configured by an inverter conversion device that is capable of forward / reverse conversion operation connected to a DC system and that supplies power to a load, a failure group of the resistance chopper devices stops a gate block, and the resistance chopper device The sound group continues to operate, and a phase signal setting means for setting a carrier phase signal set in advance by the detection signal of the operation group of the resistance chopper device or the stop group of the resistance chopper device, and the phase difference of the carrier phase signal. , 360 ° / operation group, switching timing control means, a phase shift carrier phase signal of the switching timing control means, and a control signal. Power conversion device having a gate pulse signal generating means adapted to operate the resistor chopper device at the gate pulse signals obtained by. 2. The power conversion device according to claim 1,
When the number of operation groups of the resistance chopper device changes, when changing from a carrier phase signal in operation to a phase shift carrier phase signal, it is set to the same value as the phase difference value of the carrier phase signal before the temporary change. Power conversion device. 3. The power conversion device according to claim 1,
When the number of operation groups of the resistance chopper device changes, when the carrier phase signal in operation is changed to a phase shift carrier phase signal, it is performed by instantaneously shifting to the changed phase. 4. The power conversion device according to claim 1,
A power conversion device characterized in that the value of the phase signal is shifted at the same time from the time when the operation group of the resistance chopper device changes in phase shifting timing of the carrier phase signal. 5. The power conversion device according to claim 1, wherein
A power conversion device characterized in that the value of the phase signal is shifted from the phase advance group from the time when the operation group of the resistance chopper device changes in the phase shift timing of the carrier phase signal.