JP2016181947A - Power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power converter capable of sustaining the driving of a dynamo-electric machine, even upon occurrence of such an abnormality that an inverter cannot be neutralized.SOLUTION: A first inverter 20 is connected with one ends of coils 11-13, and a second inverter 30 is connected with the other ends of the coils 11-13. A first power supply side switch 51 is provided between a first voltage source 40 and the first inverter 20. A second power supply side switch 52 is provided between a second voltage source 45 and the second inverter 30. A first connection line switch 54 is provided in a first connection line 53 connecting the high potential side of the first inverter 20 and the low potential side of the first inverter 20. A second connection line switch 56 is provided in a second connection line 55 connecting the high potential side of the second inverter 30 and the low potential side of the second inverter 30. Consequently, driving of a motor generator 10 can be sustained, even upon occurrence of such an abnormality that the first inverter 20 or second inverter 30 cannot be neutralized.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power conversion device.

  Conventionally, an inverter drive system that converts electric power of a motor by two inverters is known. For example, in Patent Document 1, the phase of the fundamental wave component of the pulse width modulation signal (hereinafter referred to as “PWM”) of the first inverter system and the second inverter system at a high voltage is 180 [°. By shifting, the two power supplies are electrically connected in series, and the motor is driven by the sum of the two power supply voltages. Further, in Patent Document 1, at the time of a low voltage, either one of the upper arm or the lower arm of the first inverter system or the second inverter system is simultaneously turned on for three phases, and the other is PWM driven.

JP 2006-238686 A

In the inverter drive system of Patent Document 1, for example, when an abnormality occurs on one inverter side, if the inverter on the side where the abnormality has occurred can be neutralized, the other inverter is used to continue driving the motor. Is possible. However, if an abnormality that cannot neutralize the inverter on the side where the abnormality has occurred, such as a short-circuit failure or an open failure of the upper and lower arms, or a failure of the driver circuit, the rotating electrical machine cannot be driven.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a power conversion device capable of continuing to drive a rotating electrical machine even when an abnormality that cannot neutralize an inverter occurs. There is.

The power converter of the present invention is a power converter for converting the power of a rotating electrical machine having a winding, and includes a first inverter, a second inverter, a first power supply side switch, and a second power supply side switch. And a first connection line, a first connection line switch, a second connection line, and a second connection line switch.
The first inverter has a first switching element having a return function, and is connected to one end of the winding and the first voltage source.
The second inverter has a second switching element having a return function, and is connected to the other end of the winding and the second voltage source.

The first power supply side switch is provided between the first voltage source and the first inverter.
The second power supply side switch is provided between the second voltage source and the second inverter.
The first connection line connects the high potential side of the first inverter and the low potential side of the first inverter closer to the first inverter than the first power supply side switch.
The first connection line switch is provided on the first connection line.
The second connection line connects the high potential side of the second inverter and the low potential side of the second inverter on the second inverter side of the second power supply side switch.
The second connection line switch is provided on the second connection line.

  The power converter of the present invention is provided with a first connection line and a first connection line switch. One end side of the coil regardless of the state of the first inverter by closing the first connection line switch with the first power supply side switch open and the first voltage source disconnected from the first inverter Can be neutralized.

Moreover, the power converter is provided with a second connection line and a second connection line switch. With the second power supply side switch open and the second voltage source disconnected from the second inverter, the second connection line switch is closed, so that the other end of the coil is independent of the state of the second inverter. The side can be neutralized.
Thereby, even if it is a case where abnormality which cannot neutralize a 1st inverter or a 2nd inverter arises, a drive of a rotary electric machine can be continued.

It is a schematic block diagram which shows the power converter device by one Embodiment of this invention. It is explanatory drawing explaining the one-side drive operation | movement by one Embodiment of this invention. It is explanatory drawing explaining the inversion drive operation | movement by one Embodiment of this invention. In one Embodiment of this invention, it is explanatory drawing explaining the control when the abnormality which cannot make a 1st inverter or a 2nd inverter neutralize occurs. It is a schematic block diagram which shows the power converter device by other embodiment of this invention. It is a schematic block diagram which shows the power converter device by a reference example.

Hereinafter, a power converter according to the present invention will be described with reference to the drawings.
(One embodiment)
A power converter according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the rotating electrical machine drive system 1 includes a motor generator 10 as a rotating electrical machine and a power conversion device 15.

  The motor generator 10 is a so-called “main motor” that is applied to an electric vehicle such as an electric vehicle or a hybrid vehicle and generates torque for driving drive wheels (not shown). The motor generator 10 has a function as an electric motor for driving the drive wheels, and a function as a generator that generates electric power by being driven by kinetic energy transmitted from an engine or drive wheels (not shown). In this embodiment, the case where the motor generator 10 functions as an electric motor will be mainly described.

  Motor generator 10 is a three-phase AC rotating machine, and includes U-phase coil 11, V-phase coil 12, and W-phase coil 13. The U-phase coil 11, the V-phase coil 12, and the W-phase coil 13 correspond to “windings”, and the U-phase coil 11, the V-phase coil 12, and the W-phase coil 13 are hereinafter appropriately referred to as “coils 11 to 13”.

  The power conversion device 15 converts the power of the motor generator 10, and includes a first inverter 20, a second inverter 30, a first power supply side switch 51, a second power supply side switch 52, and a first connection line 53. , A first connection line switch 54, a second connection line 55, a second connection line switch 56, driver circuits 61 to 64, a control unit 70, and the like.

  The first inverter 20 is a three-phase inverter that switches energization to the coils 11 to 13, and includes U1 upper arm element 21, V1 upper arm element 22, W1 upper arm element 23, and U1 lower arm element 24 that are six switching elements. , V1 lower arm element 25, and W1 lower arm element 26. Hereinafter, the U1 upper arm element 21, the V1 upper arm element 22, the W1 upper arm element 23, the U1 lower arm element 24, the V1 lower arm element 25, and the W1 lower arm element 26 are appropriately referred to as “(first) switching elements 21 to 21”. 26 ".

  The U1 upper arm element 21 is connected to the high potential side of the U1 lower arm element 24, the V1 upper arm element 22 is connected to the high potential side of the V1 lower arm element 25, and the W1 upper arm element 23 is connected to the W1 lower arm element 26. Connected to the high potential side. Hereinafter, the U1 upper arm element 21, the V1 upper arm element 22 and the W1 upper arm element 23 connected to the high potential side are referred to as “(first) upper arm elements 21 to 23” and the lower U1 connected to the low potential side. The arm element 24, the V1 lower arm element 25, and the W1 lower arm element 26 are referred to as “(first) lower arm elements 24-26”.

  The first inverter 20 is connected between one end 111, 121, 131 of the coils 11, 12, 13 and the first battery 41. Specifically, a connection point 27 between the paired U1 upper arm element 21 and U1 lower arm element 24 is connected to one end 111 of the U-phase coil 11, and connection between the V1 upper arm element 22 and the V1 lower arm element 25 is performed. Point 28 is connected to one end 121 of V-phase coil 12, and connection point 29 between W1 upper arm element 23 and W1 lower arm element 26 is connected to one end 131 of W-phase coil 13. The high potential side wiring 46 that connects the high potential side of the first upper arm elements 21 to 23 is connected to the positive electrode of the first battery 41, and the low potential that connects the low potential side of the first lower arm elements 24 to 26. The side wiring 47 is connected to the negative electrode of the first battery 41.

  The second inverter 30 is a three-phase inverter that switches energization to the coils 11 to 13, and is a U2 upper arm element 31, a V2 upper arm element 32, a W2 upper arm element 33, and a U2 lower arm element 34 that are six switching elements. , V2 lower arm element 35 and W2 lower arm element 36. The U2 upper arm element 31, the V2 upper arm element 32, the W2 upper arm element 33, the U2 lower arm element 34, the V2 lower arm element 35, and the W2 lower arm element 36 are appropriately referred to as “(second) switching elements 31 to 36”. That's it.

  The U2 upper arm element 31 is connected to the high potential side of the U2 lower arm element 34, the V2 upper arm element 32 is connected to the high potential side of the V2 lower arm element 35, and the W2 upper arm element 33 is connected to the W2 lower arm element 36. Connected to the high potential side. The U2 upper arm element 31, the V2 upper arm element 32, and the W2 upper arm element 33 connected to the high potential side are hereinafter referred to as “(second) upper arm elements 31 to 33”, and the lower U2 connected to the low potential side. The arm element 34, the V2 lower arm element 35, and the W2 lower arm element 36 are referred to as “(second) lower arm elements 34 to 36”.

The second inverter 30 is connected between the other ends 112, 122, 132 of the coils 11, 12, 13 and the second battery 42. Specifically, a connection point 37 between the paired U2 upper arm element 31 and U2 lower arm element 34 is connected to the other end 112 of the U-phase coil 11, and the V2 upper arm element 32 and the V2 lower arm element 35 are connected to each other. A connection point 38 is connected to the other end 122 of the V-phase coil 12, and a connection point 39 between the W2 upper arm element 33 and the W2 lower arm element 36 is connected to the other end 132 of the W-phase coil 13. Further, the high potential side wiring 48 that connects the high potential side of the second upper arm elements 31 to 33 is connected to the positive electrode of the second battery 42, and the low potential that connects the low potential side of the second lower arm elements 34 to 36. The side wiring 49 is connected to the negative electrode of the second battery 42.
Thus, in this embodiment, the 1st inverter 20 and the 2nd inverter 30 are connected to the both sides of the coils 11-13.

  In the present embodiment, the switching elements 21 to 26 and 31 to 36 are IGBTs (insulated gate bipolar transistors), and all have free-wheeling diodes. That is, when the switching elements 21 to 26 and 31 to 36 are turned on, a current flows from the high potential side to the low potential side, and when the switching elements 21 to 26 and 31 to 36 are turned off, the current from the high potential side to the low potential side is interrupted. Further, the switching elements 21 to 26 and 31 to 36 are allowed to be energized from the low potential side to the high potential side via the freewheeling diodes regardless of the on / off state. That is, it can be said that the switching elements 21 to 26 and 31 to 36 of the present embodiment have a reflux function that allows energization from the low potential side to the high potential side.

The first voltage source 40 includes a first battery 41 and a first capacitor 43.
The first battery 41 is a chargeable / dischargeable DC power source such as a lithium ion battery, and is connected to the first inverter 20 so as to be able to exchange power with the motor generator 10 via the first inverter 20.
The first capacitor 43 is connected to the high potential side wiring 46 and the low potential side wiring 47. The first capacitor 43 is a smoothing capacitor that smoothes the current from the first battery 41 to the first inverter 20 side or the current from the first inverter 20 to the first battery 41 side.

The second voltage source 45 includes a second battery 42 and a second capacitor 44.
The second battery 42 is a chargeable / dischargeable DC power source such as a lithium ion battery, and is connected to the second inverter 30 so as to be able to exchange power with the motor generator 10 via the second inverter 30.
The second capacitor 44 is connected to the high potential side wiring 48 and the low potential side wiring 49. The second capacitor 44 is a smoothing capacitor that smoothes the current from the second battery 42 to the second inverter 30 or the current from the second inverter 30 to the second battery 42.

  The first power supply side switch 51 is provided between the first battery 41 and the first inverter 20. In the present embodiment, the first power supply side switch 51 is provided in the first high-potential side wiring 46 on the first inverter 20 side than the location where the positive electrode of the first capacitor 43 is connected. When the first power supply side switch 51 is closed, energization between the first battery 41 and the first capacitor 43 and the first inverter 20 is allowed, and when the first power supply side switch 51 is open, the first battery The energization between the first and second capacitors 41 and 43 and the first inverter 20 is cut off.

  The second power supply side switch 52 is provided between the second battery 42 and the second inverter 30. In the present embodiment, the second power supply side switch 52 is provided in the second high potential side wiring 48 on the second inverter 30 side than the location where the negative electrode of the second capacitor 44 is connected. When the second power supply side switch 52 is closed, energization between the second battery 42 and the second capacitor 44 and the second inverter 30 is allowed, and when the second power supply side switch 52 is opened, the second battery The energization between 42 and the second capacitor 44 and the second inverter 30 is cut off.

The first connection line 53 connects the first high potential side wiring 46 and the first low potential side wiring 47 closer to the first inverter 20 than the first power supply side switch 51.
The first connection line switch 54 is provided in the first connection line 53. When the first connection line switch 54 is closed, energization of the first connection line 53 is allowed, and when the first connection line switch 54 is open, energization of the first connection line 53 is interrupted.

The second connection line 55 connects the second high potential side wiring 48 and the second low potential side wiring 49 closer to the second inverter 30 than the second power supply side switch 52.
The second connection line switch 56 is provided on the second connection line 55. When the second connection line switch 56 is closed, energization of the second connection line 55 is allowed, and when the second connection line switch 56 is open, energization of the second connection line 55 is cut off.

The first driver circuit 61 outputs a gate signal corresponding to the control signal output from the inverter control unit 71 to the gates of the first switching elements 21 to 26.
The second driver circuit 62 outputs a gate signal corresponding to the control signal output from the inverter control unit 71 to the gates of the second switching elements 31 to 36.
The third driver circuit 63 drives the first connection line switch 54 in response to a signal from the switch control unit 72.
The fourth driver circuit 64 drives the second connection line switch 56 in response to a signal from the switch control unit 72.

In the present embodiment, the first driver circuit 61, the second driver circuit 62, the third driver circuit 63, and the fourth driver circuit 64 are independent. For example, when an abnormality occurs in the first driver circuit 61, Even in this case, the first connection line switch 54 can be driven by the third driver circuit 63.
The first power supply side switch 51 and the second power supply side switch 52 are also provided with corresponding driver circuits, but the description is omitted in FIG.

  The control unit 70 is configured as a normal computer, and includes a CPU, a ROM, a RAM, an I / O, a bus line connecting these configurations, and the like. Each processing in the control unit 70 may be software processing by executing a program stored in advance by the CPU, or may be hardware processing by a dedicated electronic circuit.

The control unit 70 includes an inverter control unit 71, a switch control unit 72, an abnormality detection unit 73, and the like as functional blocks.
The inverter control unit 71 generates a control signal for controlling the on / off operation of the switching elements 21 to 26 and 31 to 36 based on a command value related to driving of the motor generator 10 such as a torque command value and a current command value. The generated control signal is output to the driver circuits 61 and 62. As a result, the inverter control unit 71 controls the first inverter 20 and the second inverter 30 via the driver circuits 61 and 62.

The switch control unit 72 controls the opening and closing of the first power supply side switch 51, the second power supply side switch 52, the first connection line switch 54, and the second connection line switch 56. The control lines to the first power supply side switch 51 and the second power supply side switch 52 are omitted in order to avoid complication.
The abnormality detection unit 73 detects an abnormality in the first inverter 20 and the second inverter 30.

  First, normal control when both the first inverter 20 and the second inverter 30 are normal will be described with reference to FIGS. 2 and 3. In FIGS. 2 and 3, elements that are turned on are indicated by solid lines, and elements that are turned off are indicated by broken lines. In addition, descriptions of some components and symbols such as the control unit 70 are omitted as appropriate. The same applies to FIG.

  When both the first inverter 20 and the second inverter 30 are normal, the switch control unit 72 closes the first power supply side switch 51 and the second power supply side switch 52, the first connection line switch 54 and The second connection line switch 56 is opened. In the one-side drive operation described later, when the second inverter 30 side is neutralized, the second power supply side switch 52 may be opened, and when the first inverter 20 side is neutralized, The power supply side switch 51 may be opened.

When driving the motor generator 10 with a relatively light load, the motor generator 10 is driven by the electric power of the first battery 41 or the second battery 42. The operation that is driven by the power of the first battery 41 or the second battery 42 is referred to as a one-side drive operation.
As shown in FIG. 2A, when the motor generator 10 is driven by the electric power of the first battery 41, all phases of the second upper arm elements 31 to 33 or all phases of the second lower arm elements 34 to 36 are used. One is turned on, the other is turned off, and the second inverter 30 is neutralized. Further, the first inverter 20 is controlled by PWM control or the like according to the drive request of the motor generator 10. The PWM control includes “sine wave PWM control” in which the amplitude of the fundamental wave corresponding to the command is equal to or less than the amplitude of the carrier wave such as a triangular wave, and “overmodulation PWM control in which the amplitude of the fundamental wave is larger than the amplitude of the carrier wave. Is included.

  In the example shown in FIG. 2A, all the phases of the second upper arm elements 31 to 33 are turned on, and all the phases of the second lower arm elements 34 to 36 are turned off, so that the second inverter 30 is neutral. It becomes. In the first inverter 20, when the U1 upper arm element 21, the V1 lower arm element 25, and the W1 lower arm element 26 are turned on, a current in a path indicated by a two-dot chain line arrow flows.

  As shown in FIG. 2B, when the motor generator 10 is driven by the power of the second battery 42, all phases of the first upper arm elements 21 to 23 or all phases of the first lower arm elements 24 to 26 are used. One is turned on, the other is turned off, and the first inverter 20 is neutralized. Further, the second inverter 30 is controlled by PWM control or the like according to the drive request of the motor generator 10.

  In the example shown in FIG. 2B, all phases of the first upper arm elements 21 to 23 are turned on, and all phases of the first lower arm elements 24 to 26 are turned off, so that the first inverter 20 is neutral. It becomes. In the second inverter 30, when the U2 upper arm element 31, the V2 lower arm element 35, and the W2 lower arm element 36 are turned on, a current in a path indicated by a two-dot chain line arrow flows.

When neutralizing the second inverter 30 side, the second upper arm elements 31 to 33 are turned on and the second lower arm elements 34 to 36 are turned on in accordance with the thermal deterioration of the switching elements 31 to 36. The state to be performed may be switched as appropriate. The same applies to the case where the first inverter 20 side is neutralized.
The inverter to be neutralized may be appropriately switched according to the thermal deterioration of the switching elements 21 to 26 and 31 to 36. Further, the inverter that is not neutralized is not limited to PWM control, and may be controlled in any manner such as rectangular wave control.

In the one-side drive operation, one inverter is neutralized. As a result, the switching loss is reduced as compared with an inversion driving operation described later that switches the switching elements 21 to 26 and 31 to 36 of the two inverters 20 and 30, and thus the efficiency at the time of low output can be increased. .
In addition, when the voltage of the first battery 41 and the voltage of the second battery 42 are different, when the drive request can be satisfied with the output with the lower voltage, the high voltage side is neutralized and driven on the low voltage side. , Switching loss can be further reduced.

When driving the motor generator 10 with a relatively high load that cannot satisfy the drive request with the power of the first battery 41 or the second battery 42, the first battery 41 and the second battery 42 are connected in series, Double-sided power drive using a double-sided power supply. In the present embodiment, the first inverter 20 and the second inverter 30 are driven in an inverted manner so as to be driven on both sides.
Here, the first inverter 20 is PWM-controlled by comparing the first fundamental wave F1 and the carrier wave, and the second inverter 30 is PWM-controlled by comparing the second fundamental wave F2 and the carrier wave. .

  In the inversion driving operation, the phases of the first fundamental wave F1 and the second fundamental wave F2 are inverted. In other words, the first fundamental wave F1 and the second fundamental wave F2 are out of phase by approximately 180 [°]. Thereby, it can be considered that the first battery 41 and the second battery 42 are connected in series, and a voltage corresponding to the sum of the voltage of the first battery 41 and the voltage of the second battery 42 is set to the motor generator 10. Can be applied.

The phase difference between the first fundamental wave F1 and the second fundamental wave F2 is 180 [°], but a voltage corresponding to the sum of the voltage of the first battery 41 and the voltage of the second battery 42 is set to the motor generator 10. It is assumed that a deviation that can be applied to is allowed.
Further, the amplitude of the first fundamental wave F1 and the amplitude of the second fundamental wave F2 may be equal or different.

  Further, the first fundamental wave F1 and the second fundamental wave F2 may be similar waveforms so as to be both sine waves, or one of the first inverter 20 or the second inverter 30 is subjected to sine wave PWM control, Different waveforms may be used as in the case of overmodulation PWM control of the other. Further, the rectangular wave control in which the amplitude is infinite and the on / off state is switched every half cycle of the fundamental waves F1 and F2 may be used. The rectangular wave control can be said to be 180-degree energization control. Moreover, it is good also as 120 degree electricity supply control based on fundamental wave F1 and F2 instead of rectangular wave control.

When the amplitude and the waveform of the first fundamental wave F1 and the second fundamental wave F2 are equal, the elements that are turned on in each phase are upside down in the first inverter 20 and the second inverter 30. In the example shown in FIG. 3, when the U1 upper arm element 21, the V1 lower arm element 25, the W1 lower arm element 26, the V2 upper arm element 32, the W2 upper arm element 33, and the U2 lower arm element 34 are turned on, A current in a path indicated by a two-dot chain line arrow flows.
In the inversion driving operation, when the amplitudes and waveforms of the fundamental waves F1 and F2 are different, the elements that are turned on in each phase are not necessarily upside down between the first inverter 20 and the second inverter 30.
As described above, when the first inverter 20 and the second inverter 30 are normal, the motor generator 10 is driven with high efficiency by switching between the one-side drive operation and the reverse drive operation according to the drive request of the motor generator 10. can do.

Next, control when abnormality occurs in the first inverter 20 or the second inverter 30 will be described. Here, the case where an abnormality occurs in the first inverter 20 and the second inverter 30 is normal will be mainly described.
When at least one of the first upper arm elements 21 to 23 is short-circuited, all the phases of the first upper arm elements 21 to 23 are turned on, and all the phases of the first lower arm elements 24 to 26 are turned off. Is neutralized, and the second inverter 30 is controlled according to the drive request of the motor generator 10, so that the drive of the motor generator 10 can be continued in the one-side drive operation.
When at least one of the first lower arm elements 24 to 26 is short-circuited, all the phases of the first lower arm elements 24 to 26 are turned on, and all the phases of the first upper arm elements 21 to 23 are turned off. By driving the neutral inverter and controlling the second inverter 30 according to the drive request of the motor generator 10, the drive of the motor generator 10 can be continued in the one-side drive operation.

Further, when at least one of the first upper arm elements 21 to 23 fails to open, the first inverter is turned on by turning on all phases of the first lower arm elements 24 to 26 and turning off all phases of the first upper arm elements 21 to 23. By driving the neutral inverter 20 and controlling the second inverter 30 according to the drive request of the motor generator 10, the drive of the motor generator 10 can be continued in the one-side drive operation.
When at least one of the first lower arm elements 24 to 26 has an open failure, the first inverter 20 is turned on with all phases of the first upper arm elements 21 to 23 turned on and all phases of the first lower arm elements 24 to 26 turned off. Is neutralized and the second inverter 30 is controlled according to the drive request of the motor generator 10, so that the drive of the motor generator 10 can be continued in the one-side drive operation.
That is, even if an abnormality occurs in the first inverter 20, if the first inverter 20 can be neutralized, the driving of the motor generator 10 can be continued by performing the one-side driving operation described in FIG. .

Here, in the power converter 19 without the first connection line 53, the first connection line switch 54, the second connection line 55, and the second connection line switch 56, as in the reference example shown in FIG. When an abnormality that prevents the first inverter 20 from being neutralized occurs, the motor generator 10 cannot be driven. Examples of the abnormality in which the first inverter 20 cannot be neutralized include a case where a short circuit failure or an open failure of the upper and lower arms, or a case where an abnormality occurs in the first driver circuit 61. Here, the abnormality of the first driver circuit 61 and the second driver circuit 62 is also included in the concept of “abnormality of the first inverter and the second inverter”.
In FIG. 6, the description of the control unit and the like is omitted.

  In the present embodiment, as shown in FIG. 4A, when an abnormality that cannot neutralize the first inverter 20 occurs, the switch control unit 72 includes the second power supply side switch 52 and the first connection line. The switch 54 is closed, and the first power supply side switch 51 and the second connection line switch 56 are opened. Further, the inverter control unit 71 controls the second inverter 30 in response to a drive request for the motor generator 10. For example, as shown in FIG. 4A, when the U2 upper arm element 31, the V2 lower arm element 35, and the W2 lower arm element 36 are turned on, a current in a path indicated by a two-dot chain line arrow flows.

  That is, in this embodiment, when an abnormality that cannot neutralize the first inverter 20 occurs, the first power supply side switch 51 is opened and the first voltage source 40 is electrically disconnected from the first inverter 20. Above, the 1st connection line switch 54 is closed, and the 1st inverter 20 side is neutralized using the free-wheeling diode of the 1st switching elements 21-26. In the example shown in FIG. 4A, current flows through the free wheel diode of the U1 upper arm element 23, the first connection line 53, the lower arm element 25 of the V1 and the free wheel diode of the W1 lower arm element 26. The side is neutralized.

  As a result, even if an abnormality that cannot neutralize the first inverter 20 occurs, the first inverter 20 side is placed in the middle using the free wheel diodes of the first switching elements 21 to 26 and the first connection line 53. Since it is possible to make a point, the driving of the motor generator 10 can be continued.

  In particular, in the present embodiment, a first driver circuit 61 related to the control of the first inverter 20 and a third driver circuit 63 related to the control of the first connection line switch 54 are separately provided. Therefore, even if an abnormality occurs in the first driver circuit 61 and the first switching elements 21 to 26 can no longer be turned on / off, the opening / closing of the first connection line switch 54 can be controlled. By making it closed, the first inverter 20 side can be neutralized.

  In addition, as shown in FIG. 4B, when an abnormality that cannot neutralize the second inverter 30 occurs, the switch control unit 72 includes the first power supply side switch 51 and the second connection line switch 56. Is closed, and the second power supply side switch 52 and the first connection line switch 54 are opened. Further, the inverter control unit 71 controls the first inverter 20 in response to a drive request for the motor generator 10. For example, as shown in FIG. 4B, when the U1 upper arm element 21, the U1 lower arm element 25, and the W1 lower arm element 26 are turned on, a current in a path indicated by a two-dot chain line arrow flows.

  That is, in this embodiment, when an abnormality that cannot neutralize the second inverter 30 occurs, the second power supply side switch 52 is opened and the second voltage source 45 is electrically disconnected from the second inverter 30. Above, the 2nd connection line switch 56 is closed, and the 2nd inverter 30 side is neutralized using the free-wheeling diode of the 2nd switching elements 31-36. In the example shown in FIG. 4B, a current flows through the free wheel diode of the U2 upper arm element 31, the second connection line 55, the V2 lower arm element 35, and the free diode of the W2 lower arm element 36. The side is neutralized.

  As a result, even if an abnormality that cannot neutralize the second inverter 30 occurs, the second inverter 30 side is set to the middle by using the free wheel diodes of the second switching elements 31 to 36 and the second connection line 55. Since it is possible to make a point, the driving of the motor generator 10 can be continued.

  In particular, in the present embodiment, a second driver circuit 62 related to the control of the second inverter 30 and a fourth driver circuit 64 related to the control of the second connection line switch 56 are separately provided. Therefore, even if an abnormality occurs in the second driver circuit 62 and the second switching elements 31 to 36 cannot be turned on / off, the opening / closing of the second connection line switch 56 can be controlled. By making it closed, the second inverter 30 side can be neutralized.

Note that the first inverter 20 can be neutralized by controlling the switching elements 21 to 26 of the first inverter 20 when, for example, the U1 upper arm element 21 has a short circuit failure or an open failure. Even in such a case, as described with reference to FIG. 4A, the first connection line 53 is used by opening the first power supply side switch 51 and closing the first connection line switch 54. Thus, the first inverter 20 side may be neutralized. Whether neutralization is performed by controlling the first inverter 20 or neutralization using the first connection line 53 can be appropriately selected in consideration of, for example, heat generation and efficiency.
The same applies to the case where the second inverter 30 side is neutralized.

As described above in detail, the power conversion device 15 of the present embodiment converts the power of the motor generator 10 having the coils 11 to 13, and includes the first inverter 20, the second inverter 30, and the first A power supply side switch 51, a second power supply side switch 52, a first connection line 53, a first connection line switch 54, a second connection line 55, and a second connection line switch 56 are provided. .
The first inverter 20 includes first switching elements 21 to 26 having a reflux function, and is connected to one end 111, 121, 131 of the coils 11, 12, 13 and the first voltage source 40.
The second inverter 30 includes second switching elements 31 to 36 having a reflux function, and is connected to the other ends 112, 122, 132 of the coils 11, 12, 13 and the second voltage source 45.

The first power supply side switch 51 is provided between the first voltage source 40 and the first inverter 20. The second power supply side switch 52 is provided between the second voltage source 45 and the second inverter 30.
The first connection line 53 connects the high potential side of the first inverter 20 and the low potential side of the first inverter 20 closer to the first inverter 20 than the first power supply side switch 51.
The first connection line switch 54 is provided in the first connection line 53.
The second connection line 55 connects the high potential side of the second inverter 30 and the low potential side of the second inverter 30 closer to the second inverter 30 than the second power supply side switch 52.
The second connection line switch 56 is provided on the second connection line 55.

  In the present embodiment, the power conversion device 15 is provided with a first connection line 53 and a first connection line switch 54. Regardless of the state of the first inverter 20 by closing the first connection line switch 54 in a state where the first power source side switch 51 is opened and the first voltage source 40 is disconnected from the first inverter 20. The one end 111, 121, 131 side of the coils 11, 12, 13 can be neutralized.

The power converter 15 is provided with a second connection line 55 and a second connection line switch 56. Depending on the state of the second inverter 30, the second connection line switch 56 is closed while the second power source switch 52 is opened and the second voltage source 45 and the second inverter 30 are disconnected. First, the other ends 112, 122, 132 of the coils 11, 12, 13 can be neutralized.
Thereby, even if the abnormality which cannot neutralize the 1st inverter 20 or the 2nd inverter 30 arises, the drive of the motor generator 10 can be continued.

The power conversion device 15 further includes a control unit 70. The control unit 70 includes an abnormality detection unit 73, an inverter control unit 71, and a switch control unit 72.
The abnormality detection unit 73 detects an abnormality in the first inverter 20 and the second inverter 30.
The inverter control unit 71 controls the first inverter 20 and the second inverter 30 according to the abnormal state of the first inverter 20 and the second inverter 30.
The switch control unit 72 includes a first power supply side switch 51, a second power supply side switch 52, a first connection line switch 54, and a second connection line according to the abnormal state of the first inverter 20 and the second inverter 30. The opening / closing of the switch 56 is controlled.
Thereby, according to the abnormal state of the 1st inverter 20 and the 2nd inverter 30, inverter 20,30 and switch 51,52,54,56 can be controlled appropriately.

When an abnormality that cannot neutralize the first inverter 20 occurs, the switch controller 72 closes the second power supply side switch 52 and the first connection line switch 54, and sets the first power supply side switch 51 and the first switch The two connection line switch 56 is opened. Moreover, the switch control part 72 is. When an abnormality that cannot neutralize the second inverter 30 occurs, the first power supply side switch 51 and the second connection line switch 56 are closed, and the second power supply side switch 52 and the first connection line switch 54 are connected. Open.
Thus, even when an abnormality that cannot neutralize the first inverter 20 occurs, the first inverter 20 side can be neutralized, so that the motor generator 10 can be continuously driven. Further, even when an abnormality that cannot neutralize the second inverter 30 occurs, the second inverter 30 side can be neutralized, so that the driving of the motor generator 10 can be continued.
In the present embodiment, the abnormality detection unit 73 corresponds to “abnormality detection unit”, the inverter control unit 71 corresponds to “inverter control unit”, and the switch control unit 72 corresponds to “switch control unit”.

(Other embodiments)
(A) Switching element In the said embodiment, a switching element is IGBT which has a free-wheeling diode. In other embodiments, the switching element may be a MOSFET (metal oxide semiconductor field effect transistor) having a parasitic diode or the like. Further, the switching element is not limited to a device having a built-in free wheel diode, and a free wheel diode may be externally attached.

(A) Switch In the above embodiment, all switches are illustrated as mechanical relays. In another embodiment, a semiconductor relay may be used instead of the mechanical relay. The first power supply side switch 81, the second power supply side switch 82, the first connection line switch 84, and the second connection line switch 86 shown in FIG. 5A are a combination of two IGBTs. The first power supply side switch 91, the second power supply side switch 92, the first connection line switch 94, and the second connection line switch 96 shown in FIG. 5B are a combination of one IGBT and four diodes. Is,

When a semiconductor relay is used as a switch, a device that can be energized bidirectionally when closed is used, as illustrated in FIG.
In other embodiments, different types of switches may be used.
In the said embodiment, a 1st power supply side switch is provided in the positive electrode side of a 1st voltage source. In another embodiment, the first power supply side switch may be provided on the negative electrode side of the first voltage source, or may be provided on the positive electrode side and the negative electrode side. The same applies to the second power supply side switch.

(C) First voltage source, second voltage source In the above embodiment, the first voltage source has a first battery and a first capacitor, and the second voltage source has a second battery and a second capacitor. In other embodiments, the first voltage source and the second voltage source may omit the capacitor.
In the said embodiment, the lithium ion battery etc. were illustrated as a 1st battery and a 2nd battery. In other embodiments, the first battery and the second battery may be lead storage batteries other than lithium ion batteries, fuel cells, and the like. Further, the first voltage source and the second voltage source may be of the same type and characteristics, or may be different types and characteristics. Moreover, it is good also as capacitors, such as an electric double layer capacitor and a lithium ion capacitor, replacing with one of a 1st battery or a 2nd battery. One of the first voltage source and the second voltage source may be a generator that is driven by a driving source such as an engine to generate electric power.

(D) Rotating electrical machine In the above embodiment, the rotating electrical machine is a motor generator. In another embodiment, the rotating electrical machine may be an electric motor that does not have a function of a generator, or may be a generator that does not have a function of an electric motor. Further, the rotating electrical machine of the above embodiment has three phases. In other embodiments, the rotating electrical machine may have four or more phases. In the above embodiment, the rotating electrical machine drive system is not connected to the ground. However, in other embodiments, the rotating electrical machine drive system may be connected to the ground.

In the above embodiment, the rotating electrical machine is a main motor of an electric vehicle. In another embodiment, the rotating electrical machine is not limited to the main motor, but may be a so-called ISG (Integrated Starter Generator) having both a starter function and an alternator function, or an auxiliary motor. Moreover, you may apply a power converter device to apparatuses other than a vehicle.
As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.
Good.
As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.

10 ... Motor generator (rotary electric machine)
11-13 ... Coil (winding)
DESCRIPTION OF SYMBOLS 15 ... Power converter 20 ... 1st inverter 30 ... 2nd inverter 51 ... 1st power supply side switch 52 ... 2nd power supply side switch 53 ... 1st connection line 54 ... first connection line switch 55 ... second connection line 56 ... second connection line switch 70 ... control unit

Claims (3)

A power converter for converting electric power of a rotating electrical machine (10) having windings (11-13),
A first inverter (20) having a first switching element (21-26) having a reflux function and connected to one end of the winding and a first voltage source (40);
A second inverter (30) having a second switching element (31-36) having a reflux function and connected to the other end of the winding and a second voltage source (45);
A first power supply side switch (51, 81, 91) provided between the first voltage source and the first inverter;
A second power supply side switch (52, 82, 92) provided between the second voltage source and the second inverter;
A first connection line (53) for connecting the high potential side of the first inverter and the low potential side of the first inverter on the first inverter side of the first power supply side switch;
A first connection line switch (54, 84, 94) provided in the first connection line;
A second connection line (55) for connecting the high potential side of the second inverter and the low potential side of the second inverter on the second inverter side of the second power supply side switch;
A second connection line switch (56, 86, 96) provided on the second connection line;
A power conversion device comprising:   An abnormality detection means (73) for detecting an abnormality of the first inverter and the second inverter, an inverter control for controlling the first inverter and the second inverter according to an abnormal state of the first inverter and the second inverter Means (71), and the first power supply side switch, the second power supply side switch, the first connection line switch, and the second connection according to abnormal states of the first inverter and the second inverter. The power converter according to claim 1, further comprising a controller (70) having a switch control means (72) for controlling opening and closing of the line switch. The switch control means includes
When an abnormality that cannot neutralize the first inverter occurs, the second power supply side switch and the first connection line switch are closed, and the first power supply side switch and the second connection line switch are closed. Open and
When an abnormality that cannot neutralize the second inverter occurs, the first power supply side switch and the second connection line switch are closed, and the second power supply side switch and the first connection line switch are closed. The power conversion device according to claim 2, wherein the power conversion device is open.

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