JP2021175247A - Power conversion device - Google Patents

Abstract

To solve the problem that problems such as wiring complication, enlargement, power loss caused by increase of switching loss, heating, etc., may be incurred by complicated and long wiring in a device in which, in a case where a failure occurs in an arm, an auxiliary redundant arm supports this arm and continues a power converting operation, relating to a power conversion device to which power is supplied from a DC power source.SOLUTION: Arms are provided as many as a number resulting from adding 1 to the number of phases of a coil, and the plurality of arms also function as a redundant arm with respect to a specific phase. An arm in which abnormality is detected is separated, and a power converting operation is continued by switching a relay, such that it is not necessary to provide a redundant arm which requires specific complicated and long wiring.SELECTED DRAWING: Figure 1

Description

The present application relates to a power converter.

A power conversion device that converts a direct current into an alternating current and conversely converts the alternating current into a direct current by using a switching element is used. This power conversion device is also called an inverter, and the positive electrode side switching circuit that supplies current from the positive electrode side of the DC power supply to the load is the upper arm, and the negative electrode side switching circuit that draws the current from the load to the negative electrode side of the DC power supply is the lower arm. Refer to. Further, an arm in which an upper arm and a lower arm are connected in series is called an arm.

Applications of the power converter include, for example, control of a multi-phase AC motor. In order to continue the control of the polyphase AC motor when an abnormality occurs in each of the above arms, there is a method of preparing a spare redundant arm to maintain the function of the power conversion device.

A redundant arm corresponding to each phase arm of the multi-phase inverter is provided, and when a failure occurs in the arm of the multi-phase inverter, the redundant arm is used instead. Patent Document 1 discloses a motor control device that continues to control the drive of a motor without changing the command value of the multi-phase inverter from the normal state.

However, in the technique disclosed in Patent Document 1, since one redundant arm corresponds to all the phase arms, the wiring from the coil winding terminal of the motor to the redundant arm intersects and becomes complicated. At the same time, there is a possibility that the redundant arm may be connected to the arm of the non-failed phase due to the wrong connection destination of the redundant arm to each phase arm.

Further, when the power supply has a high voltage, it is necessary to secure an insulation distance, so that the space required for wiring from the coil winding terminal of the motor to the redundant arm becomes large, and it becomes difficult to miniaturize the motor control device. Further, the wiring impedance from the redundant arm to each coil winding of the motor becomes large, and there are concerns about heat generation of the motor control device, increase in radiation noise, and interference of current between the coil windings of the motor.

In particular, for the gate drive circuit that drives the upper arm and the lower arm, the gate drive signal must be switched from the abnormal arm to the redundant arm. To achieve this, it is necessary to route the gate drive signal wiring of all phases of the arm to the redundant arm. Therefore, the wiring becomes complicated, and the length of each wiring is also different. Since the length of the gate drive wiring to the normal arm of each phase and the gate drive wiring to the redundant arm are different, the gate rise time and fall time of the redundant arm become large, and the loss due to the switching of the redundant arm increases. Problems such as inefficiency and increased heat generation occur.

Japanese Patent No. 5569626

The present application relates to a power conversion device that receives power from a DC power supply, and in a device in which a spare redundant arm supplements the power conversion operation when the arm fails and the power conversion operation is continued, the wiring of the power conversion device is performed by complicated and long wiring. The purpose is to suppress the occurrence of problems such as complication, upsizing, power loss due to increase in switching loss, and heat generation.

The power conversion device according to the present application is
Multi-phase windings of rotary electric machines with connection terminals for each phase,
A positive electrode side switching element connected to the positive electrode side of the DC power supply, a negative electrode side switching element connected to the negative electrode side of the DC power supply, and a positive electrode side switching element and a negative electrode side switching element are connected in series to form an external connection point. N + 1 arms with 1 added to the number of phases N of the winding, which has the first wiring provided, and
When N + 1 arms are numbered in order, 2N relays are provided between the external connection points of the two arms with adjacent numbers, and 2N relays are provided.
A second wire that connects two relays in series between the external connection points of two arms with adjacent numbers, and
The third wiring that connects the output point provided between the two relays connected in series and the connection terminal of each phase of the second wiring,
It is provided with a relay control unit that turns on and off 2N relays so that an external connection point of one arm is connected to each connection terminal of each phase.

In the power conversion device according to the present application, a plurality of arms have the function of a redundant arm for a specific phase, the arm in which an abnormality is detected is disconnected, and the relay is switched to continue the power conversion operation. It is not necessary to provide a redundant arm that requires complicated and long wiring, simplification and miniaturization of wiring of the power conversion device can be realized, and problems such as power loss and heat generation due to an increase in switching loss can be suppressed. ..

It is a block diagram which shows the structure of the power conversion apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the 1st example of the contact part of the relay of the power conversion apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the 2nd example of the contact part of the relay of the power conversion apparatus which concerns on Embodiment 1. FIG. It is a hardware block diagram of the control device of the power conversion device which concerns on Embodiment 1. FIG. It is a flowchart explaining the relay switching operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 1. FIG. It is a time chart explaining operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the register in the storage device for the current control part of the power conversion device which concerns on Embodiment 1. FIG. It is a flowchart explaining the operation of the control device at the time of failure detection of the switching element of the power conversion device which concerns on Embodiment 2. It is a flowchart explaining the relay switching operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 2. It is a time chart explaining operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 2. FIG. It is a block diagram which shows the structure of the power conversion apparatus which concerns on Embodiment 3. It is a 1st block diagram which shows the structure of the power conversion apparatus which concerns on Embodiment 4. FIG. It is a second block diagram which shows the structure of the power conversion apparatus which concerns on Embodiment 4. FIG. It is a flowchart explaining the 1st relay switching operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 4. FIG. It is a flowchart explaining the 2nd relay switching operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 4. FIG. It is a schematic block diagram which shows the structure of the arm drive signal switching part of the power conversion apparatus which concerns on embodiment 5. It is a block diagram which shows the structure of the arm drive signal switching part of the power conversion apparatus which concerns on Embodiment 5. It is a time chart explaining operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 5. FIG. It is a block diagram which shows the structure of the arm drive signal switching part of the power conversion apparatus which concerns on Embodiment 6. It is a time chart explaining operation at the time of failure detection of the switching element of the power conversion apparatus which concerns on Embodiment 6.

Embodiments Hereinafter, embodiments of the power conversion device according to the present application will be described with reference to the drawings. Examples of control of a three-phase AC motor and a two-phase AC motor will be described in Embodiments 1 to 6 as applications of the power conversion device. The power conversion device according to the present application can be applied not only to a DC-AC conversion device but also to an arm of a power conversion device in various fields such as a DC-AC-DC power conversion device and an AC-DC conversion device.

1. 1. Embodiment 1
FIG. 1 is a block diagram showing a configuration of the power conversion device 1 according to the first embodiment. FIG. 2 is a diagram showing a first example of a contact portion of a relay of the power conversion device 1 according to the first embodiment. FIG. 3 is a diagram showing a second example of the contact portion of the relay of the power conversion device 1 according to the first embodiment. FIG. 4 is a hardware configuration diagram of the control device 100 of the power conversion device 1 according to the first embodiment. FIG. 5 is a flowchart illustrating a relay switching operation at the time of failure detection of the switching element of the power conversion device 1 according to the first embodiment. FIG. 6 is a time chart illustrating an operation at the time of failure detection of the switching element of the power conversion device 1 according to the first embodiment. FIG. 7 is a diagram showing a register 51 in the storage device 91 for the current control unit 10 of the power conversion device 1 according to the first embodiment.

<Configuration of power converter>
Hereinafter, the components and functions of the power conversion device 1 of the first embodiment will be described. The power conversion device 1 of FIG. 1 is connected to the DC power supply 2 and the rotary electric machine 3, and has a function of converting the DC power obtained from the DC power supply 2 into AC power and controlling the rotation and torque of the rotary electric machine 3.

The power conversion device 1 includes a first relay 5, a second relay 6, a third relay 15, a fourth relay 16, a fifth relay 17, a sixth relay 18, and a switching element. 4, a relay control unit 8, a failure detection unit 9, and a current control unit 10 are provided.

The power conversion device 1 has a first arm 80 to a fourth arm 83 in which two switching elements 4 are connected in series. The number of arms is the number (N + 1) obtained by adding 1 to the number of phases N (N = 3 in FIG. 1) of the winding of the rotary electric machine 3. The switching element 4 on the positive electrode side is connected to the positive electrode side of the DC power supply 2, and the switching element 4 on the negative electrode side is connected to the negative electrode side of the DC power supply 2. The switching element 4 on the positive electrode side and the switching element 4 on the negative electrode side are connected in series by the first wiring 41. The first wiring 41 is provided with an external connection point 44, and transmits the output of the switching element 4 on the positive electrode side and the switching element 4 on the negative electrode side to the outside. The switching element 4 on the positive electrode side may be referred to as an upper arm, and the switching element 4 on the negative electrode side may be referred to as a lower arm. An arm is composed of a switching element 4 on the positive electrode side, a switching element 4 on the negative electrode side, and a first wiring 41. Two relays are provided between the external connection points 44 of the adjacent arms of the first arm 80 to the fourth arm 83 arranged in parallel, for a total of six (2N) relays. A relay is provided. The external connection points 44 of the adjacent arms are connected by a second wiring 42 that connects two relays in series. The output point 45 provided in the portion between the two relays connected in series of the second wiring 42 and the third wiring 43 to which the three connection terminals 46 of the windings of the rotary electric machine 3 are connected respectively. exist. Specifically, the output point 45 between the first relay 5 and the second relay 6, the third relay 15, the output point 45 between the fourth relay 16, the fifth relay 17, and the sixth relay. The output point 45 between the relays 18 is connected to the connection terminal 46 of the winding of the rotary electric machine 3.

Here, in FIG. 1, the first arm 80, the second arm 81, the first relay 5, the second relay 6, and the third relay 15 form a module 7, and the third arm 82 and the third arm 82. The fourth arm 83, the fourth relay 16, the fifth relay 17, and the sixth relay 18 also form the module 7. By handling the switching element 4, the relay, and the wiring thereof as a block, the standardization of the electronic circuit can be promoted, so that the design and manufacturing efficiency of the power conversion device 1 can be improved.

As the switching element 4, for example, a MOS-FET (metal oxide film semiconductor field effect transistor) and an IGBT (insulated gate bipolar transistor) can be considered. Further, as the first relay 5 to the sixth relay 18, for example, as shown in FIG. 2, a mechanical relay that opens and closes the mechanical contact portion 11 by passing a current from the control terminal 12 to the coil winding. Can be done. Alternatively, as shown in FIG. 3, a configuration as an electronic relay using two MOS-FETs 40 in which parasitic diodes are connected in series so as to be opposite to each other as a semiconductor switch can be considered.

If a wide bandgap semiconductor using silicon carbide or gallium nitride-based material as the MOS-FET is used for the switching element 4 or electronic relay, it can be applied to products that use a high voltage for the DC power supply 2. It will be possible. Further, the cooling structure of the MOS-FET 40 can be simplified by utilizing the characteristic that it can be used up to a high temperature, and the product can be miniaturized.

The failure detection unit 9 has a function of detecting a short-circuit failure or a disconnection failure of the switching element 4 constituting the arm and notifying the failure of the arm. Various specific configurations and methods for failure detection have been proposed, and these techniques can be applied. The hardware configuration will be described later.

The current control unit 10 has a function of outputting an alternation signal to a switching element 4 constituting an arm according to the rotation speed and rotation torque of the rotary electric machine 3. Further, as will be described later, it has a function of switching the drive signal of the arm according to the coil winding terminal of the rotary electric machine 3. The relay control unit 8 has a function of controlling the electrical opening and closing of the first to sixth relays that electrically connect the arm and the coil winding of the rotary electric machine 3.

<Control device>
The relay control unit 8, the failure detection unit 9, and the current control unit 10 are functional blocks of the control device 100. FIG. 4 is a hardware configuration diagram of the control device 100 of the power conversion device 1 according to the first embodiment. In the present embodiment, each function of the control device 100 is realized by a processing circuit provided in the control device 100. Specifically, as shown in FIG. 4, the control device 100 is a storage device 91 that exchanges data with an arithmetic processing unit 90 (computer) such as a CPU (Central Processing Unit) and an arithmetic processing unit 90 as a processing circuit. An input circuit 92 for inputting an external signal to the arithmetic processing unit 90, an output circuit 93 for outputting a signal from the arithmetic processing unit 90 to the outside, and the like are provided.

The arithmetic processing device 90 is provided with an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, various signal processing circuits, and the like. You may. Further, a plurality of arithmetic processing units 90 of the same type or different types may be provided, and each processing may be shared and executed. As the storage device 91, a RAM (Random Access Memory) configured to be able to read and write data from the arithmetic processing device 90, a ROM (Read Only Memory) configured to be able to read data from the arithmetic processing device 90, and a flash memory. Etc. are provided. The input circuit 92 includes an A / D converter or the like to which various sensors and switches are connected and the output signals of these sensors and switches are input to the arithmetic processing device 90. The output circuit 93 includes a drive circuit or the like to which an electric load is connected and the control signal from the arithmetic processing device 90 is converted and output to the electric load.

For each function included in the control device 100, the arithmetic processing unit 90 executes software (program) stored in the storage device 91 such as a ROM, and the control device 100 such as the storage device 91, the input circuit 92, and the output circuit 93. This is achieved by working with other hardware. Setting data such as threshold values and determination values used by the control device 100 are stored in a storage device 91 such as a ROM as a part of software (program).

The functions of the components of the control device 100 of FIG. 1 will be described. Each function shown in the relay control unit 8, the failure detection unit 9, and the current control unit 10 described inside the control device 100 of FIG. 1 may be composed of software modules, respectively. It may be composed of a combination of software and hardware.

Here, the relay control unit 8, the failure detection unit 9, and the current control unit 10 have been described as functional blocks executed in the control device 100, but each of them may be independently provided as a dedicated control device. ..

<Processing flowchart>
FIG. 5 is a flowchart showing a relay switching operation by the relay control unit 8 of the power conversion device 1 according to the first embodiment. Hereinafter, the relay switching operation by the relay control unit 8 of the power conversion device 1 will be specifically described with reference to the flowchart shown in FIG.

The relay control unit 8 turns on the first relay 5, the third relay 15, and the fifth relay 17, and the first arm 80 to the third arm 82 are electrically connected to the rotary electric machine 3. It is assumed that the failure detection unit 9 determines the failure of any of the first arm 80 to the third arm 82 in this state. Starting from step S99, in step S100, the failure detection unit 9 determines which of the first arm 80 to the third arm 82 has detected a failure. Since the fourth arm 83 is not used, the case of failure of the fourth arm 83 is not included. The second relay 6, the fourth relay 16, and the sixth relay 18 are in the off state.

If the failure detection unit 9 has detected a failure of the third arm 82, the process proceeds to step S101. If a failure of the second arm 81 is detected, the process proceeds to step S103. If a failure of the first arm 80 has been detected, the process proceeds to step S105.

If the third arm 82 has failed, in step S101, the fifth relay 17 connected to the external connection point 44 of the failed third arm 82 is turned off and electrically disconnected from the coil winding. , Step S102. In step S102, the sixth relay 18 connected to the external connection point 44 of the fourth arm 83 is turned on, the process proceeds to step S109, and the relay switching process is completed.

If the second arm 81 has failed, in step S103, the third relay 15 connected to the external connection point 44 of the failed second arm 81 is turned off and electrically disconnected from the coil winding. , Step S104. In step S104, the fourth relay 16 to the sixth relay 18 connected to the external connection point 44 of the arm that has not failed are switched on and off (the output is inverted), and the process proceeds to step S109 to switch the relays. End the process.

If the first arm 80 is out of order, in step S105, the first relay 5 is turned off, electrically disconnected from the coil winding, and the process proceeds to step S106. In step S106, the second relay 6 to the sixth relay 18 are switched on and off (the output is inverted), the process proceeds to step S109, and the relay switching process is completed.

<Time chart>
FIG. 6 is a time chart showing an example of the switching timing of the drive signal of the arm by the current control unit 10 together with the relay switching of the relay control unit 8 shown in FIG. Hereinafter, the relay switching operation of the power conversion device 1 will be specifically described with reference to the time chart shown in FIG.

At the time t1 of FIG. 6, the failure detection unit 9 detects the failure of the first arm 80 and notifies the detected failure content to the outside of the failure detection unit 9. Then, the relay control unit 8 receives the failure content detected and notified by the failure detection unit 9, and performs a relay switching operation according to the failure content. Since the failure content at time t1 is the failure of the first arm 80, the relay control unit 8 switches the first relay 5 from on to off at time t2 according to the processing of the flowchart shown in FIG.

After that, the relay control unit 8 waits for the elapse of a predetermined time, reverses the on and off of the second relay 6 to the sixth relay 18 at the time t3, and ends the relay switching operation. Here, at the time t3, in switching the relay on and off (inverting the output), the off is preceded and the on is executed after a predetermined delay time. As the delay time, for example, a method is conceivable in which a transient time during which the relay actually switches off after receiving the off command is calculated or measured in advance, and that time is set as the delay time. The first relay 5 and the second relay 6, the third relay 15 and the fourth relay 16, the fifth relay 17 and the sixth relay 18 are connected to the same coil terminal by providing a delay time, respectively. While avoiding the opportunity to turn on at the same time, the power is generated when the second relay 6 and the third relay 15, the fourth relay 16 and the fifth relay 17 are turned on at the same time, that is, the terminals of the coil winding are short-circuited. It is possible to reliably prevent an erroneous short circuit of the arm due to the conversion operation.

After the relay switching operation of the relay control unit 8 is completed, the current control unit 10 sets the drive signal of each arm at time t4 based on the on / off states of the first to sixth relays by the relay control unit 8. The power conversion device 1 can perform the power conversion operation again. As a method of switching the drive signal of each arm by the current control unit 10, for example, as shown in FIG. 7, the register 51 of the storage device 91 in the control device 100 is set in advance according to the coil winding terminal of the rotary electric machine. A method of changing the arrangement of the registers 51 according to the switching of the relay can be considered. Here, using a one-chip microcomputer in which the arithmetic processing unit (CPU) 90, the storage device 91, the input circuit 92, and the output circuit 93 of FIG. 4 are integrated, the register 51 of the storage device 91 in the microcomputer is used. You may.

In the first embodiment, the first wiring 41 in which the positive electrode side switching element 4 connected to the positive electrode side of the DC power supply 2 and the switching element 4 connected to the negative electrode side are connected in series and an external connection point 44 is provided. An arm composed of N + 1 is provided by adding 1 to the number of phases N of the winding of the rotary electric machine 3. Numbering is performed in the order of N + 1 arms, and two relays are provided between the external connection points 44 of the two arms having adjacent numbers, so that a total of 2N relays are provided. A second wiring 42 for connecting two relays in series is provided between the external connection points 44 of the two arms having adjacent numbers. An output point 45 is provided in a portion of the second wiring 42 between relays connected in series, and a third wiring connecting each output point 45 and each connection terminal 46 of the winding of the rotary electric machine 3 is provided. This is a power conversion device 1. Since power can be supplied to any of the connection terminals 46 of the coil of the specific one or two systems via two relays, the normally used arm also has the function of a redundant arm. The arm in which the abnormality is detected can be disconnected, and the relay can be switched to connect the standby arm as a spare redundant arm to continue the power conversion operation.

Since the connection of each arm is switched only with the connection terminal 46 of a specific coil winding and the drive signal of the arm is switched according to the switching state of the relay, it is possible to avoid an error in the switching destination.

Since the arm composed of the switching element 4 also has the function of a redundant arm and can supply power to the connection terminal 46 of either one or two windings of the rotary electric machine 3 via a relay. Each phase arm including the relay and the redundant arm can be standardized and modularized, and the cost required for the additional configuration of the redundant arm can be reduced.

Since the arm has the function of a redundant arm and can be modularized, the wiring between the arm of the module and the coil winding terminal of the rotary electric machine 3 can be simplified without crossing, and the power conversion device 1 can be miniaturized. Become.

Further, it is possible to arrange so that the wiring distances from each arm to the connection terminal 46 of the winding of the rotary electric machine 3 are equal, the wiring impedance is also the same, and power conversion occurs even after an arm failure occurs. The level of heat generation and radiation noise of the device does not change. In addition, current interference between coil windings does not occur, the wiring of the switched arm becomes long, and the power conversion operation can be continued without leading to delays in turning on and off the switching element in current control. ..

In FIG. 5, a failure occurs when the relay control unit 8 is electrically connected to the rotary electric machine 3 with the first relay 5, the third relay 15, and the fifth relay 17 turned on. The relay switching operation in the case of this is explained. However, the present embodiment is not limited to this, and a failure occurs in a state where the second relay 6, the fourth relay 16, and the sixth relay 18 are turned on and electrically connected to the rotary electric machine 3. Even if this happens, the power conversion operation can be continued by the relay switching operation. That is, the third arm 82 in the flowchart of FIG. 5 is replaced with the second arm 81, the second arm 81 is replaced with the third arm 82, the first arm 80 is replaced with the fourth arm 83, and the step. The process of S101 is replaced with the second relay 6, the process of step S102 is replaced with the first relay 5, the process of step S103 is replaced with the second relay 6, and the process of step S104 is replaced with the first relay 5. Is replaced with the third relay 15, the process of step S105 is replaced with the sixth relay 18, and the process of step S106 is replaced with the first relay 5 to the fifth relay 17.

2. Embodiment 2
FIG. 8 is a flowchart illustrating the operation of the control device at the time of failure detection of the switching element of the power conversion device 1 according to the second embodiment. FIG. 9 is a flowchart illustrating a relay switching operation at the time of failure detection of the switching element of the power conversion device according to the second embodiment. FIG. 10 is a time chart illustrating the operation at the time of failure detection of the switching element of the power conversion device according to the second embodiment.

In the first embodiment, the case where there is no induced current in the coil winding of the rotary electric machine 3 has been described. In the second embodiment, the present invention is not limited to this, and an induced current may be present in the coil winding, and the same effect can be obtained by devising a relay switching method. For example, FIG. 8 shows a relay switching operation when an induced current is flowing in the coil winding of the rotary electric machine 3 as the power conversion device 1 according to the second embodiment. The configuration of the power conversion device 1 is the same as that in FIG. The operation will be described below.

The process is started from step S199, and in step S200, the failure detection unit 9 determines whether or not a failure has occurred in the arm, and if a failure has occurred, the process proceeds to step S201, and the failure has not occurred. For example, the process proceeds to step S209 and the process is completed without performing the relay switching operation. In step S201, the current control unit 10 stops driving all the arms in order to stop the current control, and proceeds to step S202. In step S202, the relay control unit 8 performs a relay switching operation according to the content of the failure, and proceeds to step S203. The relay switching operation in step S202 is performed according to the flowchart shown in FIG. 9 described later.

In step S203, the current control unit 10 changes the correspondence between the coil terminal and the arm for current control based on the on / off state of the first relay 5 to the sixth relay 18 by the relay control unit 8. The arm drive signal is switched, and the process proceeds to step S204. In step S204, the current control unit 10 restarts the drive of the arm in order to restart the current control, proceeds to step S209, and ends the relay switching process due to the failure of the arm.

As a method for detecting that an induced current is flowing in the coil winding, for example, a method using a coil current detection unit (not shown) that detects the coil current for the purpose of controlling the rotation and torque of the rotary electric machine 3. Can be considered. Various specific configurations and methods for current detection have been proposed, and since these techniques can be applied, the description thereof will be omitted here. In addition, as a method of detecting that an induced current is flowing in the coil winding of the rotary electric machine 3, the voltage of the coil winding terminal of the rotary electric machine 3 is measured, and the induced voltage of the coil winding terminal generated by the induced current is measured. Is conceivable. Therefore, an induced voltage detection unit that detects the induced voltage by measuring the coil winding voltage is provided, and when the induced voltage is detected, the relay control unit 8 performs on control when inverting the on and off of the relay. The off control may be performed after the off delay time has elapsed. Various specific configurations and methods for voltage detection have been proposed, and since these techniques can be applied, the description thereof will be omitted here.

Alternatively, it can be determined that the induced current is generated when the rotary electric machine 3 is rotating at high speed. The rotation speed of the rotary electric machine 3 is obtained by a rotation speed detector, and when the rotation speed is equal to or higher than a predetermined determination rotation speed, the relay switching operation by the relay control unit 8 is turned on and off when the arm failure is detected. The on-control may be preceded when the on-control is inverted, and the off-control may be performed after the off-delay time elapses. The optimum value of the determination rotation speed may be obtained by an experiment.

FIG. 9 is a flowchart showing a relay switching operation by the relay control unit 8 of the power conversion device 1 according to the second embodiment. Hereinafter, the relay switching operation by the relay control unit 8 of the power conversion device 1 will be specifically described with reference to the flowchart shown in FIG.

In the relay control unit 8, the failure detection unit 9 is the first arm in a state where the first relay 5, the third relay 15, and the fifth relay 17 are turned on and electrically connected to the rotary electric machine 3. It is assumed that a failure of any of the arms 80 to the third arm 82 is determined. The process is started from step S209, and in step S210, it is determined which failure of the first arm 80 to the third arm 82 is detected by the failure detection unit 9. Since the fourth arm 83 is not used, it is excluded from the failure target.

If the failure detection unit 9 has detected a failure of the third arm 82, the process proceeds to step S211. If a failure of the second arm 81 is detected, the process proceeds to step S213. If a failure of the first arm 80 has been detected, the process proceeds to step S215.

If the third arm 82 is out of order, in step S211 the sixth relay 18 is turned on and the process proceeds to step S212. In step S212, the fifth relay 17 connected to the external connection point 44 of the failed arm is turned off, electrically disconnected from the coil winding, and the process proceeds to step S219 to end the relay switching process.

If the second arm 81 has failed, in step S213, the fourth relay 16 to the sixth relay 18 connected to the external connection point 44 of the other non-failed arm are switched on and off ( Invert the output) and proceed to step S214. In step S214, the third relay 15 connected to the external connection point 44 of the failed arm is turned off, electrically disconnected from the coil winding, and the process proceeds to step S219 to end the relay switching process.

If the first arm 80 is out of order, in step S215, the second relay 6 to the sixth relay 18 are switched on and off (the output is inverted), and the process proceeds to step S216. In step S216, the first relay 5 is turned off, electrically disconnected from the coil winding, and the process proceeds to step S219 to end the relay switching process.

FIG. 10 is a time chart showing an example of the switching timing of the arm drive signal by the current control unit 10 together with the relay switching of the relay control unit 8 shown in FIG. Hereinafter, the relay switching operation of the power conversion device 1 will be specifically described with reference to the time chart shown in FIG.

At the time t10 of FIG. 10, the failure detection unit 9 detects the failure of the first arm and notifies the detected failure content to the outside of the failure detection unit 9. Then, the relay control unit 8 receives the failure content detected and notified by the failure detection unit 9, and performs a relay switching operation according to the failure content. Since the failure content at the time t10 is the failure of the first arm, the relay control unit 8 switches the second to sixth relays on and off at the time t11 according to the processing of the flowchart shown in FIG.

At time t12, the relay control unit 8 switches the first relay 5 from on to off, and ends the relay switching operation. It should be noted that from t11 to t12, the coil winding terminals are in a short-circuited state, and the regenerative brake is generated in the rotary electric machine 3. Therefore, after the corresponding relay is turned on first in t11, it is quickly turned on and off. By turning off the switching relay and minimizing the occurrence of the regenerative brake, the rotation fluctuation of the rotary electric machine 3 can be minimized.

After the relay switching operation of the relay control unit 8 is completed, the current control unit 10 sets each of the relay control units 8 at time t13 based on the on / off states of the first relay 5 to the sixth relay 18 by the relay control unit 8. Update the assignment to the coil terminal of the arm and switch the drive signal. In the power conversion device 1, the current control unit 10 resumes current control from time t14. That is, the power conversion operation of the power conversion device 1 becomes possible again.

As described above, in the second embodiment, as in the first embodiment, N + 1 arms connected to the DC power supply 2 and composed of the switching element 4 are added by 1 to the number of phases N of the windings of the rotary electric machine 3. It is provided. The positive electrode side switching element 4 connected to the positive electrode side of the DC power supply 2 and the negative electrode side switching element 4 connected to the negative electrode side of the DC power supply 2 are connected in series by the first wiring 41. An external connection point 44 is provided on one wiring 41. For N + 1 arms arranged in parallel, the external connection points 44 of adjacent arms are connected in series by a second wire 42 via two relays. The power conversion device 1 in which each output point 45 provided in the portion between the two relays of the second wiring 42 is connected to the connection terminal 46 of the winding of the rotary electric machine 3 by the third wiring 43, respectively. Is. Since each arm can supply power to either a specific one-system or two-system winding connection terminal 46 via a relay, each arm also functions as a redundant arm and disconnects the arm in which an abnormality is detected. At the same time, the relay can be switched to continue the power conversion operation.

Since the arm is switched so that it can be connected only to the connection terminal 46 of a specific coil winding, and the drive signal of the arm is switched according to the switching state of the relay, it is possible to avoid an error in the switching destination.

Since the arm composed of the switching element 4 also has the function of a redundant arm, and can selectively supply power to the connection terminals 46 of the windings of two different systems of the rotary electric machine 3 via two relays. , Each phase arm including the relay and the redundant arm can be standardized and modularized, and the cost for the additional configuration of the redundant arm can be reduced.

Since the normal arm also has the function of a redundant arm, the wiring between the arm of the module 7 and the connection terminal 46 of the winding of the rotary electric machine 3 can be simplified without crossing, and the power conversion device 1 can be miniaturized. It becomes.

Further, it is possible to arrange the wires so that the wiring distances from each arm to the connection terminal 46 of the winding of the rotary electric machine 3 are equal, and if the wiring impedances are matched, the power conversion device can be used even after the arm has failed. The power conversion operation can be continued without changing the heat generation and radiation noise of the coil and without causing current interference between the coil windings.

In FIG. 9, the relay control unit 8 fails when the first relay 5, the third relay 15, and the fifth relay 17 are turned on and electrically connected to the rotary electric machine 3. The relay switching operation in the case of the above is described, but the present embodiment is not limited to this, and the second relay 6, the fourth relay 16, and the sixth relay 18 are turned on and electrically connected to the rotary electric machine 3. In this state, even if a failure occurs, the power conversion operation can be continued by the relay switching operation. That is, the third arm 82 in the flowchart of FIG. 9 is replaced with the second arm 81, the second arm 81 is replaced with the third arm 82, the first arm 80 is replaced with the fourth arm 83, and the step. The process of S211 is replaced with the first relay 5, the process of step S212 is replaced with the second relay 6, the process of step S213 is replaced with the first relay 5 to the third relay 15, and the process of step S214. Is replaced with the second relay 6, the process of step S215 is replaced with the first relay 5 to the fifth relay 17, and the process of step S216 is replaced with the sixth relay 18.

When the induced current is flowing in the coil winding of the rotary electric machine 3, the relay control unit 8 executes the relay switching operation after the relay is turned on, so that the induced voltage does not jump due to the interruption of the current path. It is possible to minimize the influence of relay switching on the rotation fluctuation of the rotary electric machine 3. An induced voltage detection unit that detects the induced voltage by measuring the coil winding voltage is provided, and when the induced voltage is detected, the relay control unit 8 precedes the on control when inverting the on and off of the relay. , The off control may be performed after the off delay time has elapsed. Further, since it can be determined that the induced current is generated when the rotary electric machine 3 is rotating at high speed, the rotation speed of the rotary electric machine 3 is obtained by the rotation speed detector, and the rotation speed is equal to or higher than the determined rotation speed. In the case of, the relay switching operation by the relay control unit 8 when the failure of the arm is detected may be preceded by the on control when inverting the on and off of the relay, and the off control may be performed after the off delay time elapses. .. Similarly, since the relay is turned on first, it is possible to avoid the jumping of the induced voltage due to the interruption of the current path, and it is possible to minimize the influence of the relay switching on the rotation fluctuation of the rotary electric machine 3.

When the power conversion device 1 detects a failure of the switching element 4 while supplying power to the rotary electric machine 3, it stops driving the arm prior to the relay switching operation, so that an erroneous short circuit of the arm due to relay switching is avoided. can. In particular, when the relay control unit 8 connects a plurality of arms to the same winding terminal, stopping the current control by the current control unit 10 is significant in preventing a new failure of the arm. big. Further, in many cases, the power conversion device 1 as a drive device of the rotary electric machine 3 is provided with a current detection unit in the winding to detect the winding current and perform current feedback control. Even if the failure detection unit 9 detects a failure while the current is being detected by the current detector, the current control unit 10 stops the current control, that is, the drive of the arm, and then the relay control unit 8 turns on the relay. , Switch off. By doing so, it is of great significance in preventing a new failure of the arm.

3. 3. Embodiment 3
FIG. 11 is a block diagram showing the configuration of the power conversion device 1 according to the third embodiment. The power conversion device 1 of the third embodiment includes a first relay 5, a second relay 6, a third relay 15, a fourth relay 16, a fifth relay 17, and a sixth relay. It includes 18, a switching element 4, a relay control unit 8, a failure detection unit 9, and a current control unit 10.

Compared with FIG. 1 showing the configuration of the first embodiment, the modularization range is different. That is, in the module 70 shown in FIG. 11, an arm in which two switching elements 4 are connected in series is connected to a DC power supply 2, and an external connection point 44 of the two switching elements 4 constituting the arm has two relays. It is connected to the connection terminals 46 of two different winding systems of the rotary electric machine 3 via the relay. In FIG. 11, the second arm 81, the second relay 6, the third relay 15, and the third arm 82, the fourth relay 16, and the fifth relay 17 form the module 70, respectively.

Further, another module 71 is provided with two arms in parallel, and the external connection points 44 of the two switching elements 4 constituting the arms are independent of each other, and the rotary electric machine 3 is different via a relay. It is connected to the connection terminal 46 of the two windings. In FIG. 11, the first arm 80, the fourth arm 83, the first relay 5, and the sixth relay 18 form the module 71.

Since the relay control unit 8, the failure detection unit 9, and the current control unit 10 are the same as those in FIG. 1, the description thereof will be omitted.

The power conversion device 1 shown in FIG. 11 basically has a module 70 whose required number increases or decreases according to the number of connection terminals of the winding of the rotary electric machine 3, and another module 71. Since the module 70 may be increased or decreased in response to an increase or decrease in the connection terminals of the windings of the rotary electric machine, efficiency in design and manufacturing can be achieved, and cost reduction can be contributed.

4. Embodiment 4
FIG. 12 is a first block diagram showing the configuration of the power conversion device 31 according to the fourth embodiment. FIG. 13 is a second block diagram showing the configuration of the power conversion device 31 according to the fourth embodiment. FIG. 14 is a flowchart illustrating the first relay switching operation at the time of failure detection of the switching element of the power conversion device 31 according to the fourth embodiment. FIG. 15 is a flowchart illustrating a second relay switching operation at the time of failure detection of the switching element of the power conversion device 31 according to the fourth embodiment.

FIG. 12 shows a block diagram illustrating the configuration of the power conversion device 31 when the rotary electric machine 33 is a bipolar rotary electric machine. Even in the case of the two-pole rotary electric machine 33, as in the case of the three poles, N + 1 is added to the number of phases N of the windings of the rotary electric machine 33 (N = 2 in FIG. 12) (3 in FIG. 12). ) Arm is provided. The positive electrode side switching element 4 connected to the positive electrode side of the DC power supply 2 and the negative electrode side switching element 4 connected to the negative electrode side of the DC power supply 2 are connected in series by the first wiring 41. An external connection point 44 is provided on one wiring 41. For N + 1 arms arranged in parallel, the external connection points 44 of adjacent arms are connected in series by a second wire 42 via two relays. Each output point 45 provided in the portion between the two relays of the second wiring 42 is connected to the connection terminal 46 of the winding of the rotary electric machine 3 by the third wiring 43, respectively. Is. Since each arm can supply power to either a specific one-system or two-system winding connection terminal 46 via a relay, each arm also functions as a redundant arm and disconnects the arm in which an abnormality is detected. At the same time, the relay can be switched to continue the power conversion operation.

The relay control unit 38, the failure detection unit 39, and the current control unit 30 are described as functions of the control device 101. The control device 101 has the same hardware configuration as the control device 100 shown in FIGS. 1, 3 and 11 according to the first to third embodiments. When the first relay 5 to the fourth relay 16 are turned on and off by the relay control unit 38, the first arm 80 to the third arm 82 are assigned to the winding terminals of the rotary electric machine 33.

FIG. 13 shows a second block diagram showing another configuration of the power converter 31. Although FIGS. 13 and 12 are equivalent in terms of electrical circuits, the arrangement of the first arm 80 to the third arm 82 is different. By arranging as shown in FIG. 13, the same functions and effects as those of the first and second embodiments can be realized by using the module 70 and another module 71. These modules 70 and 71 are the same components as the modules shown in FIG. 11 according to the third embodiment. Therefore, by modularizing the electric circuit parts, the same module can be used regardless of whether the terminals of the rotary electric machine 33 are two terminals or three terminals, and standardization can contribute to cost reduction in both design and manufacturing.

In FIG. 13, the second arm 81, the second relay 6, and the third relay 15 form a module 70, and the first arm 80, the third arm 82, the first relay 5, and the fourth relay 16 forms another module 71.

FIG. 14 is a flowchart showing a relay switching operation by the relay control unit 38 for the configuration shown in FIG. 12 in which the two-pole rotary electric machine 33 is connected to the power conversion device 31 according to the fourth embodiment. Hereinafter, the relay switching operation by the relay control unit 38 of the power conversion device 31 will be specifically described with reference to the flowchart shown in FIG.

The relay control unit 8 is premised on a state in which the failure detection unit 39 detects a failure while the first relay 5 and the third relay 15 are turned on and electrically connected to the rotary electric machine 33. do. Starting from step S299, in step S300, it is determined whether the failure detection unit 39 has detected the failure of the first arm 80 or the second arm 81. The second relay 6 and the fourth relay 16 are in the off state.

If the failure detection unit 9 has detected a failure of the second arm 81, the process proceeds to step S301. If a failure of the first arm 80 is detected, the process proceeds to step S303.

When the failure of the second arm 81 is detected, in step S301, the third relay 15 connected to the external connection point 44 of the failed second arm 81 is turned off, and the coil winding is electrically connected. The disconnection is performed, and the process proceeds to step S302. In step S302, the first relay 5 and the fourth relay 16 connected to the external connection point 44 of the other non-failed arm are switched on and off, the process proceeds to step S309, and the relay switching process is completed. do.

When the failure of the first arm 80 is detected, in step S303, the first relay 5 is turned off, electrically disconnected from the coil winding, and the process proceeds to step S304. In step S304, the second relay 6 to the fourth relay 16 are switched on and off, the process proceeds to step S309, and the relay switching process is completed.

Further, the time chart showing an example of the switching timing of the drive signal of the arm by the current control unit 30 together with the relay switching of the relay control unit 38 shown in FIG. 14 is the same as that of FIG. 6, so the description thereof will be omitted.

Further, the coil winding may have an induced current, and the relay switching operation when the induced current is flowing in the coil winding of the rotary electric machine 33 shown in FIG. 8 described above is applied, and the flowchart shown in FIG. 15 is shown. The same effect can be obtained by switching the relay of the relay control unit 38.

FIG. 15 is intended for the configuration shown in FIG. 13 in which the two-pole rotary electric machine 33 is connected in the power conversion device 31 according to the fourth embodiment, and an induced current is flowing in the coil winding of the rotary electric machine 33. It is a flowchart which shows the relay switching operation by the relay control unit 8 in the case. Hereinafter, the relay switching operation by the relay control unit 38 of the power conversion device 31 will be specifically described with reference to the flowchart shown in FIG.

In the relay control unit 8, when the first relay 5 and the third relay 15 are turned on and electrically connected to the rotary electric machine 3, the failure detection unit 39 is the first arm 80 or the second arm 80 or the second. It is assumed that the failure of the arm 81 is determined. Starting from step S399, in step S400, it is determined whether the failure detection unit 9 has detected the failure of the first arm 80 or the second arm 81. Since the third arm 82 is not used, it is excluded from the target. If it is the second arm 81 that the failure detection unit 39 has detected the failure, the process proceeds to step S401. If it is the first arm 80 that has detected the failure, the process proceeds to step S403.

If the second arm 81 has failed, in step S401, the first relay 5 and the fourth relay 16 connected to the external connection point 44 of the other non-failed arm are turned on and off. The reverse switching is performed, and the process proceeds to step S402. In step S402, the third relay 15 connected to the external connection point 44 of the failed second arm 81 is turned off, electrically disconnected from the coil winding, the process proceeds to step S409, and the relay switching process is completed. do. If the first arm 80 has failed, in step S403, the second relay 6 to the fourth relay 16 are switched on and off in reverse, and the process proceeds to step S404. In step S404, the first relay 5 is turned off, electrically disconnected from the coil winding, and the process proceeds to step S409 to end the relay switching process.

Further, the time chart showing an example of the switching timing of the drive signal of the arm by the current control unit 30 together with the relay switching of the relay control unit 38 shown in FIG. 15 is the same as that in FIG. 10, so the description thereof will be omitted.

As described above, in the fourth embodiment, since power can be supplied to any of the connection terminals 46 of the specific one or two coils via the two relays, the normally used arm also has the function of the redundant arm. It will be. The arm in which the abnormality is detected can be disconnected, and the relay can be switched to connect the standby arm as a spare redundant arm to continue the power conversion operation.

Since the arm switches only to a specific coil winding terminal and switches the drive signal of the arm according to the switching state of the relay, it is possible to avoid an error in the switching destination.

Since the arm composed of the switching element 4 also has the function of a redundant arm and supplies power to the coil winding terminals of two different systems of the rotary electric machine 3 via two relays, the relay and the redundant arm can be used. Each phase arm including the one can be standardized and modularized, and the cost required for the additional configuration of the redundant arm can be reduced. In particular, since the arm of the present embodiment can be applied even if the rotary electric machine 33 has two poles, each phase arm can be standardized and modularized regardless of the configuration of the rotary electric machine 33, and the cost required for the additional configuration of the redundant arm. Can be further reduced.

Since the arm also has the function of a redundant arm, the wiring between the arm of the module and the coil winding terminal of the rotary electric machine 33 can be simplified without crossing, and the power conversion device 31 can be miniaturized.

Further, it is possible to arrange the wires so that the wiring distances from each arm to the coil winding terminal of the rotary electric machine 33 are equal, and if the wiring impedances are matched, the power conversion device generates heat even after the arm fails. , Radiation noise does not change, current interference between coil windings does not occur, and power conversion operation can be continued.

In addition, in FIGS. 14 and 15, the relay control unit 8 is in a state where the first relay 5 and the third relay 15 are turned on and electrically connected to the rotary electric machine 33, and a failure occurs. The relay switching operation has been described, but the present embodiment is not limited to this, and a failure occurs in a state where the second relay 6 and the fourth relay 16 are electrically connected to the rotating electric machine 33 turned on. Even if this happens, the power conversion operation can be continued by the relay switching operation. That is, the first arm 80 in the flowchart of FIG. 14 is replaced with the third arm 82, the process of step S301 is replaced with the second relay 6, and the process of step S303 is replaced with the fourth relay 16. It is possible.

Further, the first arm 80 in the flowchart of FIG. 15 is replaced with the third arm 82, the process of step S402 is replaced with the second relay 6, and the process of step S404 is replaced with the fourth relay 16. It is possible.

When the induced current is flowing in the coil winding of the rotary electric machine 33, the relay control unit 38 executes the relay switching operation after the relay is turned on, so that the induced voltage does not jump due to the interruption of the current path. It is possible to minimize the influence of relay switching on the rotation fluctuation of the rotary electric machine 33.

When the power conversion device 31 detects a failure of the switching element 4 while supplying power to the rotary electric machine 33, the power conversion device 31 stops driving the arm prior to the relay switching operation, so that an erroneous short circuit of the arm due to relay switching is avoided. can.

5. Embodiment 5
FIG. 16 is a schematic block diagram showing a configuration of an arm drive signal switching unit of the power conversion device 1 according to the fifth embodiment. FIG. 17 is a block diagram showing a configuration of an arm drive signal switching unit of the power conversion device 1 according to the fifth embodiment. FIG. 18 is a time chart illustrating the operation at the time of failure detection of the switching element of the power conversion device according to the fifth embodiment.

In the above-described first to fourth embodiments, the current control unit 10 also switches the drive signal of the arm in the switching of the relay due to the failure of the arm, but the present embodiment is not limited to this. The drive signal of the arm can be switched at a position closer to the module 7. In the configuration of the power conversion device 1 in the fifth embodiment, in addition to the configuration of FIG. 1 described above, as shown in FIG. 16, an arm drive signal switching unit 20 is provided between the current control unit 10 and the module 7.

The arm drive signal switching unit 20 has a function of transmitting an arm drive signal output by the current control unit 10 to the module 7 to drive the gate of the switching element 4 constituting the arm of the module 7. Further, the arm drive signal switching unit 20 plays a role of changing the transmission destination of the arm drive signal according to the relay switching operation of the relay control unit 8. As the arm drive signal switching unit 20, for example, the configuration shown in FIG. 17 can be considered. In FIG. 17, the arm drive signal switching unit 20 includes a gate drive circuit 21, a level shifter 22, and a selector 23.

The gate drive circuit 21 is a circuit that drives the gate of the switching element 4, and various specific configurations and methods have been proposed. Since these techniques can be applied, the description thereof will be omitted here. The level shifter 22 has a function of converting the voltage level of the drive signal of the arm and transmitting it to the gate drive circuit 21, and various specific configurations and methods have been proposed, and these techniques can be applied. Therefore, the description thereof is omitted here.

The selector 23 receives the drive signal of the arm for two different coil windings as an input, and transmits the drive signal of the arm for one of the coil windings to the arm of the module 7 according to the relay switching operation of the relay control unit 8. Has the function of In FIG. 17, since the first arm 80 and the fourth arm 83 supply power to only one coil winding, no selector is required, but the first arm 80 and the fourth arm 83 are also supplied. By providing the selector 23 and turning off one of the input signals of the selector 23, the drive of the arm can be turned off by the switching control signal of the selector 23. It is also possible to provide the selector 23 with a three-state function, set the output of the selector 23 to high impedance in response to a failure of the arm, and cut off the drive signal of the arm.

The switching control signal of the selector 23 may be controlled by, for example, a method input from the current control unit 10 and the relay control unit 8, a microcomputer and an ASIC provided in the arm drive signal switching unit 20, and the selector 23 being controlled.

FIG. 18 is a time chart showing an example of the switching timing of the arm drive signal by the arm drive signal switching unit 20 together with the relay switching of the relay control unit 8 shown in FIG. Hereinafter, the relay switching operation of the power conversion device 1 will be specifically described with reference to the time chart shown in FIG.

At time t20 in FIG. 18, the failure detection unit 9 detects a failure of the arm having only the first relay 5, and notifies the detected failure content to the outside of the failure detection unit 9. Then, the relay control unit 8 receives the failure content detected and notified by the failure detection unit 9, and performs a relay switching operation according to the failure content.

Since the failure content at time t20 is the failure of the first arm, the relay control unit 8 turns on the second relay 6 to the sixth relay 18 at time t21 according to the processing of the flowchart shown in FIG. Invert off. At time t22, the relay control unit 8 switches the first relay 5 from on to off, and ends the relay switching operation. It should be noted that from time t21 to time t22, the coil winding terminals are in a short-circuited state, and regenerative braking is generated in the rotary electric machine 3. Therefore, after the corresponding relay is turned on first at time t21, it is immediately turned on. By turning off the relay that switches from to off to minimize the occurrence of regenerative braking, it is possible to minimize the rotational fluctuation of the rotary electric machine 3.

After the relay switching operation of the relay control unit 8 is completed, the arm drive signal switching unit 20 is at time t23 based on the on / off states of the first relay 5 to the sixth relay 18 by the relay control unit 8. , The drive signal of each arm is switched by the selector 23. In FIG. 18, the selector 23 turns off the drive signal of the first arm, and the drive signal of the second arm is switched from the V-phase coil of the rotary electric machine 3 to the drive signal of the arm with respect to the U-phase coil. The drive signal of the arm is switched from the W-phase coil of the rotary electric machine 3 to the drive signal of the arm for the V-phase coil, and the drive signal of the fourth arm is turned off to the drive signal of the arm for the W-phase coil of the rotary electric machine 3. An example of switching to is shown. Then, the power conversion device 1 can perform the power conversion operation again from the time t24.

As described above, in the fifth embodiment, the number of arms connected to the DC power supply and composed of switching elements is provided by adding one to the number of coil winding terminals of the rotary electric machine, and the outside of the arms arranged in parallel. Of the connection points 44, adjacent external connection points 44 are connected by providing two relays in series, and the output point between the two relays is connected to the coil winding terminal. Since power is supplied using two of the three arms, each arm also has the function of a redundant arm, the arm in which an abnormality is detected can be disconnected, and the relay can be switched to continue the power conversion operation. ..

Since the arm switches only to a specific coil winding terminal and switches the drive signal of the arm according to the switching state of the relay, it is possible to avoid an error in the switching destination.

Since the arm composed of the switching element 4 also has the function of a redundant arm and supplies power to the coil winding terminals of two different systems via two relays, each of the relays and the redundant arm is included. The phase arm can be standardized and modularized, and the cost for additional configuration of the redundant arm can be reduced.

Since the arm also has the function of a redundant arm, the wiring between the arm of the module 7 and the coil winding terminal of the rotary electric machine 3 can be simplified without crossing, and the power conversion device 1 can be miniaturized.

Further, it is possible to arrange the wires so that the wiring distances from each arm to the coil winding terminal of the rotary electric machine 3 are equal, and if the wiring impedances are matched, the power conversion device generates heat even after the arm fails. , Radiation noise does not change, current interference between coil windings does not occur, and power conversion operation can be continued.

When the induced current is flowing in the coil winding of the rotary electric machine 3, the relay control unit 8 executes the relay switching operation after the relay is turned on, so that the induced voltage does not jump due to the interruption of the current path. It is possible to minimize the influence of relay switching on the rotation fluctuation of the rotary electric machine 3.

When the power conversion device 1 detects a failure of the switching element 4 while supplying power to the rotary electric machine 3, it stops driving the arm prior to the relay switching operation, so that an erroneous short circuit of the arm due to relay switching is avoided. can.

6. Embodiment 6
FIG. 19 is a block diagram showing a configuration of an arm drive signal switching unit 20 of the power conversion device 1 according to the sixth embodiment. FIG. 20 is a time chart illustrating an operation at the time of failure detection of the switching element of the power conversion device 1 according to the sixth embodiment.

In the fifth embodiment, a method of switching the drive signal of the arm before the input of the level shifter 22 of the arm drive signal switching unit 20 has been described in the switching of the relay due to the failure of the arm. Not limited to this, switching may be performed between the gate drive circuit 21 and the module 7.

In the configuration of the power conversion device 1 in the sixth embodiment, in addition to the configuration of FIG. 1 described above, as shown in FIG. 16, an arm drive signal switching unit 20 is provided between the current control unit 10 and the module 7. The arm drive signal switching unit 20 has a function of transmitting an arm drive signal output by the current control unit 10 to the module 7 to drive the gate of the switching element 4 constituting the arm of the module 7.

Further, the arm drive signal switching unit 20 plays a role of changing the transmission destination of the arm drive signal according to the relay switching operation of the relay control unit 8. As the arm drive signal switching unit 20, for example, the configuration shown in FIG. 19 can be considered.

In FIG. 19, the arm drive signal switching unit 20 includes a gate drive circuit 21, a level shifter 22, and a gate signal cutoff switching unit 24. The gate drive circuit 21 is a circuit that drives the gate of the switching element 4, and various specific configurations and methods have been proposed. Since these techniques can be applied, the description thereof will be omitted here.

The level shifter 22 has a function of converting the voltage level of the drive signal of the arm and transmitting it to the gate drive circuit 21, and various specific configurations and methods have been proposed, and these techniques can be applied. Therefore, the description thereof is omitted here. The gate signal cutoff switching unit 24 has a function of cutting off the gate signal for the purpose of taking measures according to an abnormality of the power conversion device 1, and is a gate that cuts off the gate drive signal of the switching element 4 constituting the arm of the module 7. A blocking unit 25 is provided.

As the gate blocking unit 25, for example, as shown in FIG. 2 described above, a mechanical relay and a semiconductor relay using a MOS-FET can be considered. In the continuity cutoff control of the gate cutoff unit 25, the power conversion operation of the power conversion device 1 is monitored by the host controller outside the power conversion device 1 or the sub-microcomputer or ASIC provided inside the power conversion device 1. If an abnormality in operation is detected, the gate blocking unit 25 blocks the gate signal.

Further, the gate signal cutoff switching unit 24 receives the gate drive signal of the arm switching element 4 for two different coil windings of the rotary electric machine 3 as an input, and one of them is used according to the relay switching operation of the relay control unit 8. It has a function of transmitting the gate drive signal of the switching element 4 of the arm with respect to the coil winding to the arm of the module 7. The switching control signal of the gate signal cutoff switching unit 24 is, for example, a method input from the current control unit 10 and the relay control unit 8, a submicrocomputer and an ASIC provided in the arm drive signal switching unit 20, and the gate signal cutoff switching unit 24. May be controlled.

FIG. 20 is a time chart showing an example of the switching timing of the gate drive signal of the arm switching element 4 by the arm drive signal switching unit 20 together with the relay switching of the relay control unit 8 shown in FIG. Hereinafter, the relay switching operation of the power conversion device 1 will be specifically described with reference to the time chart shown in FIG.

At the time t30 of FIG. 20, the failure detection unit 9 detects the failure of the first arm, and the failure detection unit 9 notifies the outside of the detected failure content. Then, the relay control unit 8 receives the failure content detected and notified by the failure detection unit 9, and performs a relay switching operation according to the failure content. Since the failure content at time t30 is the failure of the first arm, the relay control unit 8 turns on and off the second to sixth relay control units at time t31 according to the processing of the flowchart shown in FIG. Switch.

At time t32, the relay control unit 8 switches the first relay 5 from on to off, and ends the relay switching operation. It should be noted that from time t31 to time t32, the coil winding terminals are short-circuited and the regenerative brake is generated in the rotary electric machine 3. Therefore, after the corresponding relay is turned on first at time t31, it is immediately turned on. By turning off the relay that switches from to off to minimize the occurrence of regenerative braking, the rotation fluctuation of the rotary electric machine 3 can be minimized.

After the relay switching operation of the relay control unit 8 is completed, the arm drive signal switching unit 20 is at time t33 based on the on / off states of the first relay 5 to the sixth relay 18 by the relay control unit 8. , The gate drive signal of the switching element 4 of each arm is switched by the gate signal cutoff switching unit 24.

In FIG. 20, the gate signal cutoff switching unit 24 cuts off the gate drive signal of the first arm, and the gate drive signal of the second arm is the gate of the arm from the V-phase coil of the rotary electric machine 3 to the U-phase coil. The gate drive signal of the third arm is switched from the W-phase coil of the rotary electric machine 3 to the gate drive signal of the arm with respect to the V-phase coil, and the gate drive signal of the fourth arm is switched from the cutoff state to the rotary electric machine. An example of switching to the gate drive signal of the arm for the W-phase coil of No. 3 is shown. Then, the power conversion device 1 can perform the power conversion operation again from the time t24. Further, if the gate signal cutoff switching unit 24 is arranged near the module 7, the change in the wiring length of the gate drive signal of the arm can be minimized, and the fluctuation of the gate rise time and the fall time due to the switching of the gate wiring can be minimized. Can be minimized.

As described above, in the sixth embodiment, the arm connected to the DC power supply and the external connection point 44 of the arm composed of the switching element is connected to the coil winding terminal of the rotary electric machine via the relay is connected to the rotary electric machine. It is a power converter with one less number than the number of winding terminals, and since power is supplied to the coil winding terminals of two different systems via two relays, each arm also has the function of a redundant arm, which is abnormal. The arm in which is detected can be disconnected, and the relay can be switched to continue the power conversion operation.

Since the arm switches only to a specific coil winding terminal and switches the drive signal of the arm according to the switching state of the relay, it is possible to avoid an error in the switching destination.

Since the arm composed of the switching element 4 also has the function of a redundant arm, power is supplied to the coil winding terminals of two different systems via the first relay 5 and the second relay 6. , Each phase arm including the relay and the redundant arm can be standardized and modularized, and the cost for the additional configuration of the redundant arm can be reduced. Since the arm also has the function of a redundant arm, the wiring between the arm of the module 7 and the coil winding terminal of the rotary electric machine 3 can be simplified without crossing, and the power conversion device 1 can be miniaturized.

Further, it is possible to arrange the wires so that the wiring distances from each arm to the coil winding terminal of the rotary electric machine 3 are equal, and if the wiring impedances are matched, the power conversion device generates heat even after the arm fails. , Radiation noise does not change, current interference between coil windings does not occur, and power conversion operation can be continued.

When the induced current is flowing in the coil winding of the rotary electric machine 3, the relay control unit 8 executes the relay switching operation after the relay is turned on, so that the induced voltage does not jump due to the interruption of the current path. It is possible to minimize the influence of relay switching on the rotation fluctuation of the rotary electric machine 3. When the power conversion device 1 detects a failure of the switching element 4 while supplying power to the rotary electric machine 3, it stops driving the arm prior to the relay switching operation, so that an erroneous short circuit of the arm due to relay switching is avoided. can.

The power conversion device 1 described above may have a configuration in which a fuse is inserted between each arm and the DC power supply 2. Even if the arm has a short-circuit failure, the fuse cuts off only the short-circuit current path of the failed arm, so that the power conversion operation can be continued with the remaining arm after the short-circuit current is cut off.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Power converter, 2 DC power supply, 3, 33 rotary electric machine, 4 switching element, 5 1st relay, 6 2nd relay, 7, 70, 71 module, 8 relay control unit, 9 failure detection unit, 10 current Control unit, 11 mechanical contact part, 12 control terminal, 15 third relay, 16 fourth relay, 17 fifth relay, 18 sixth relay, 20 arm drive signal switching unit, 21 gate drive circuit, 22 level shifter , 23 selector, 24 gate signal cutoff switching part, 25 gate cutoff part, 40 MOS-FET, 41 first wiring, 42 second wiring, 43 third wiring, 44 external connection point, 45 output point, 46 connection Terminal, 80 1st arm, 81 2nd arm, 82 3rd arm, 83 4th arm, 100, 101 Control device

Claims (29)

Multi-phase windings of rotary electric machines with connection terminals for each phase,
The positive electrode side switching element connected to the positive electrode side of the DC power supply, the negative electrode side switching element connected to the negative electrode side of the DC power supply, and the positive electrode side switching element and the negative electrode side switching element are connected in series to the outside. An N + 1 arm having a first wiring provided with a connection point, which is obtained by adding 1 to the number of phases N of the winding.
When the N + 1 arms are numbered in order, two 2N relays are provided between the external connection points of the two adjacently numbered arms, and two relays are provided.
A second wire that connects the two relays in series between the external connection points of the two arms of the adjacent numbers, and
A third wiring for connecting an output point provided in a portion of the second wiring between two relays connected in series and a connection terminal for each phase.
A power conversion device including a relay control unit that turns on and off the 2N relays so that the external connection point of one arm is connected to each connection terminal of each phase. The power conversion device according to claim 1, wherein the external connection point of the arm can be connected to any of the specific 1 or 2 connection terminals of the winding as a power supply destination. A failure detection unit for detecting a failure of the arm is provided.
The relay control unit turns off the relay directly connected to the external connection point of the arm for which the failure detection unit has detected a failure, and connects the external connection point of the normal arm to the connection terminal of the winding. The power conversion device according to claim 1 or 2, wherein the relay is turned on or off. With four said arms and six said relays,
The external connection point of the first arm and the external connection point of the second arm are connected in series via a first relay and a second relay.
The external connection point of the second arm and the external connection point of the third arm are connected in series via a third relay and a fourth relay.
The external connection point of the third arm and the external connection point of the fourth arm are connected in series via a fifth relay and a sixth relay.
The connection terminal of the first winding of the rotary electric machine is connected to the first output point on the wiring connecting the first relay and the second relay.
The connection terminal of the second winding of the rotary electric machine is connected to the second output point on the wiring connecting the third relay and the fourth relay.
Any one of claims 1 to 3 in which the connection terminal of the third winding of the rotary electric machine is connected to a third output point on the wiring connecting the fifth relay and the sixth relay. The power converter according to the section. The first arm, the second arm, and the first to third relays are modularized.
The power conversion device according to claim 4, wherein the third arm, the fourth arm, and the fourth to sixth relays are modularized. The first arm, the fourth arm, the first relay, and the sixth relay are modularized.
The power conversion device according to claim 4, wherein the second arm, the third arm, and the second to fifth relays are modularized. A failure detection unit for detecting a failure of the arm is provided.
When the failure detection unit detects a failure of the third arm in a state where the first relay, the third relay, and the fifth relay are turned on and connected to the winding of the rotary electric machine. The power conversion device according to any one of claims 4 to 6, wherein the relay control unit turns off the fifth relay and turns on the sixth relay. A failure detection unit for detecting a failure of the arm is provided.
When the failure detection unit detects a failure of the second arm in a state where the second relay, the fourth relay, and the sixth relay are turned on and connected to the winding of the rotary electric machine. The power conversion device according to any one of claims 4 to 6, wherein the relay control unit turns off the second relay and turns on the first relay. A failure detection unit for detecting a failure of the arm is provided.
When the failure detection unit detects a failure of the second arm in a state where the first relay, the third relay, and the fifth relay are turned on and connected to the winding of the rotary electric machine. The power conversion device according to any one of claims 4 to 6, wherein the relay control unit turns off the third relay and reverses on and off of the fourth to sixth relays. A failure detection unit for detecting a failure of the arm is provided.
When the failure detection unit detects a failure of the third arm in a state where the second relay, the fourth relay, and the sixth relay are turned on and connected to the winding of the rotary electric machine. The power conversion device according to any one of claims 4 to 6, wherein the relay control unit turns off the fourth relay and reverses on and off of the first to third relays. A failure detection unit for detecting a failure of the arm is provided.
When the failure detection unit detects a failure of the first arm in a state where the first relay, the third relay, and the fifth relay are turned on and connected to the winding of the rotary electric machine. The power conversion device according to any one of claims 4 to 6, wherein the relay control unit turns off the first relay and reverses on and off of the second to sixth relays. A failure detection unit for detecting a failure of the arm is provided.
When the failure detection unit detects a failure of the fourth arm in a state where the second relay, the fourth relay, and the sixth relay are turned on and connected to the winding of the rotary electric machine. The power conversion device according to any one of claims 4 to 6, wherein the relay control unit turns off the sixth relay and reverses on and off of the first to fifth relays. The power conversion device according to any one of claims 1 to 12, wherein the wiring distance from the external connection point of the arm to the connection terminal of the winding is the same. A current control unit for driving the positive electrode side switching element and the negative electrode side switching element to control the current flowing through the winding is provided.
When the relay control unit connects the external connection points of a plurality of arms to the connection terminals of the same winding, the current control unit stops current control, any one of claims 1 to 13. The power converter according to the section. 6. Power converter. It is provided with an induced voltage detection unit that detects the induced voltage of the winding.
When the relay control unit reverses the on and off of the relay, when the induced voltage detection unit detects the induced voltage, the relay control unit precedes the on control and executes the off control after the off delay time elapses. Item 3. The power conversion device according to any one of Items 3 and 7 to 12. A rotation detection unit for detecting the rotation speed of the rotary electric machine is provided.
Any one of claims 3 and 7 to 12, wherein when the relay control unit reverses the on and off of the relay, the on control is preceded and the off control is performed after the lapse of the off delay time according to the rotation speed. The power conversion device according to one item. 17. The 17. Power converter. The power conversion device according to any one of claims 1 to 18, wherein the relay is a mechanical relay. The power conversion device according to any one of claims 1 to 18, wherein the relay is a semiconductor switch. The power conversion device according to claim 20, wherein the semiconductor switch is two metal oxide film semiconductor field effect transistors in which the parasitic diodes are in opposite directions. The power conversion apparatus according to claim 21, wherein the metal oxide film semiconductor field effect transistor is a wide bandgap semiconductor made of a material using silicon carbide or gallium nitride. A current detector that detects the current flowing through the winding,
A current control unit for driving the positive electrode side switching element and the negative electrode side switching element to control the current flowing through the winding is provided.
3. If the failure detection unit detects a failure while the current detection unit is detecting a current, the relay control unit switches the relay on and off after the current control by the current control unit is stopped. And the power converter according to any one of 7 to 12, 17 and 18. A current control unit for driving the positive electrode side switching element and the negative electrode side switching element to control the current flowing through the winding is provided.
Claims 3 and 7 to 12, wherein when the relay control unit switches the relay on and off, the current control unit switches the drive signal of the arm corresponding to the connection terminal of the winding after the connection destination is changed. The power conversion device according to any one of 17, 18 and 23. A current control unit that drives the positive electrode side switching element and the negative electrode side switching element to control the current flowing through the winding.
It is provided between the current control unit and the arm, and includes an arm drive signal switching unit that switches the connection destination of the current control unit and the arm according to switching on / off of the relay of the relay control unit.
The arm drive signal switching unit detects that the relay control unit has switched the relay on and off, and connects the current control unit and the arm according to the connection destination of the connection terminal of the winding. The power conversion device according to any one of claims 3 and 7 to 12, 17, 18 and 23. The arm drive signal switching unit has a gate drive circuit that switches between the current control unit and the connection destination of the arm.
The arm drive signal switching unit detects that the relay control unit has switched the relay on and off, and connects the current control unit and the arm according to the connection destination of the connection terminal of the winding. The power conversion device according to claim 25, wherein the destination is switched by a gate drive circuit. The arm drive signal switching unit includes a current control unit and a gate drive circuit that cuts off or switches the connection destination of the arm.
The arm drive signal switching unit detects that the relay control unit has switched the relay on and off, and connects the current control unit and the arm according to the connection destination of the connection terminal of the winding. The power conversion device according to claim 25, wherein the tip is cut off or switched by a gate drive circuit. With three said arms and four said relays,
The external connection point of the first arm and the external connection point of the second arm are connected in series via a first relay and a second relay.
The external connection point of the second arm and the external connection point of the third arm are connected in series via a third relay and a fourth relay.
The connection terminal of the first winding of the rotary electric machine is connected to the first output point on the wiring connecting the first relay and the second relay.
Any one of claims 1 to 3 in which the connection terminal of the second winding of the rotary electric machine is connected to the second output point on the wiring connecting the third relay and the fourth relay. The power converter according to the section. The first and third arms and the first and fourth relays are modularized.
28. The power conversion device according to claim 28, wherein the second arm and the second and third relays are modularized.

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