Power conversion device

Abstract

The present invention relates to a power conversion device that receives power from a DC power supply, and in which a redundant arm as a standby compensates for a failure in an arm and continues the power conversion operation, there are problems of complicated and long wiring, which causes the wiring to be complicated and large, and increases the switching loss, and thus causes power loss and heat generation. The power conversion device of the present invention has a number of arms obtained by adding 1 to the number of phases of a winding, and a plurality of arms have the function of redundant arms for specific phases, and the power conversion operation is continued by disconnecting the arm that detects an abnormality and switching a relay, so there is no need to set a redundant arm that is specifically complicated and requires long wiring.

Description

Technical Field

[0001] The present application relates to a power conversion device. Background Art

[0002] A power conversion device that uses a switching element to convert a DC current into an AC current, and vice versa, to convert an AC current into a DC current. This power conversion device is also called an inverter, and the positive-side switching circuit that provides current from the positive side of the DC power supply to the load is called the upper bridge arm, and the negative-side switching circuit that draws current from the load to the negative side of the DC power supply is called the lower bridge arm. In addition, the bridge arm formed by connecting the upper bridge arm and the lower bridge arm in series is called the arm portion.

[0003] The power conversion device is used, for example, to control a multiphase AC motor. There is a method for maintaining the function of the power conversion device by preparing a spare redundant arm in order to continue controlling the multiphase AC motor when an abnormality occurs in each of the above arms.

[0004] A redundant arm corresponding to each phase arm of the multiphase inverter is provided, and when a failure occurs in the arm of the multiphase inverter, the redundant arm is used to replace it. Thus, Patent Document 1 discloses a power conversion device as a motor control device, which does not change the command value of the multiphase inverter from the normal state and continues to control the drive of the motor.

[0005] However, in the technology disclosed in Patent Document 1, since one redundant arm corresponds to all the arm portions of each phase, the wiring from the coil winding terminal of the motor to the redundant arm crosses, making the wiring complicated. At the same time, since the redundant arm is connected to the arm portion of each phase at an incorrect destination, it is possible to connect to the arm portion of the non-faulty phase.

[0006] Furthermore, when the power supply has a high voltage, since it is necessary to ensure the insulation distance, the space required for wiring from the coil winding terminal of the motor to the redundant arm becomes large, and miniaturization of the power conversion device as the motor control device becomes difficult. In addition, the wiring impedance from the redundant arm to each coil winding of the motor becomes large, and the power conversion device as the motor control device may generate heat, increase radiation noise, and interfere with the current between the coil windings of the motor.

[0007] In particular, in the gate drive circuit for driving the upper bridge arm and the lower bridge arm, the connection target of the gate drive signal must be switched from the abnormal arm to the redundant arm. To achieve this, the gate drive signal wiring of the arms of all phases needs to be routed to the redundant arm. Therefore, the wiring becomes complicated and the lengths of the individual wirings are also different. That is, since the length of the gate drive wiring to the normal arm of each phase is different from the length of the gate drive wiring to the redundant arm, the gate rise time and fall time of the redundant arm will become longer, and the loss caused by the switching of the redundant arm will lead to reduced efficiency and increased heat generation.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent No. 5569626 Summary of the invention

[0011] Technical problem to be solved by the invention

[0012] The present application relates to a power conversion device for receiving power from a DC power supply, and its purpose is to suppress the following problems from occurring in a device in which, when an arm fails, a spare redundant arm compensates for the failure and continues the power conversion operation: the wiring of the power conversion device becomes complicated and large-scale due to complex and long wiring, the switching loss increases, and the power loss and heat generated thereby.

[0013] Technical means for solving technical problems

[0014] The power conversion device involved in this application includes:

[0015] A multiphase winding of a rotating electrical machine having connection terminals for each phase;

[0016] N+1 arms, each having a positive-side switching element connected to the positive side of a DC power supply, a negative-side switching element connected to the negative side of the DC power supply, and a first wiring connecting the positive-side switching element and the negative-side switching element in series and provided with an external connection point, and N+1 is obtained by adding 1 to the number of phases N of the winding;

[0017] 2N relays, wherein when the N+1 arms are numbered in sequence, two relays are respectively provided between external connection points of two adjacent numbered arms;

[0018] a second wiring connected in series between external connection points of two adjacent numbered arms, respectively, through two relays;

[0019] a third wiring for connecting an output point of a portion provided between two relays connected in series in the second wiring to a connection terminal of each phase; and

[0020] A relay control section is used to turn on and off the 2N relays so that an external connection point of one arm is connected to each connection terminal of each phase.

[0021] Effects of the Invention

[0022] In the power conversion device involved in the present application, since multiple arms have the function of redundant arms for specific phases, and the power conversion action is continued by separating the arm that detects the abnormality and switching the relay, there is no need to set up redundant arms that require specific complex and long wiring, thereby simplifying and miniaturizing the wiring of the power conversion device, and can suppress the occurrence of problems such as power loss and heat caused by increased switching loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a block diagram showing the configuration of the power conversion device according to the first embodiment.

[0024] Figure 2 This is a diagram showing a first example of a contact portion of a relay in the power conversion device according to the first embodiment.

[0025] Figure 3 This is a diagram showing a second example of the contact portion of the relay in the power conversion device according to the first embodiment.

[0026] Figure 4 1 is a diagram showing a hardware configuration of a control device for a power conversion device according to the first embodiment.

[0027] Figure 5 This is a flowchart for explaining the relay switching operation when a failure of a switching element of the power conversion device according to the first embodiment is detected.

[0028] Figure 6 This is a timing chart for explaining the operation of the power conversion device according to the first embodiment when a failure of a switching element is detected.

[0029] Figure 7 This is a diagram showing registers in a storage device for a current control unit of the power conversion device according to the first embodiment.

[0030] Figure 8 This is a flowchart for explaining the operation of the control device when a failure of a switching element of the power conversion device according to the second embodiment is detected.

[0031] Fig. 9This is a flowchart for explaining the relay switching operation when a failure of a switching element of the power conversion device according to the second embodiment is detected.

[0032] Fig.10 This is a timing chart for explaining the operation when a failure of a switching element of the power conversion device according to the second embodiment is detected.

[0033] Fig.11 This is a block diagram showing the structure of a power conversion device according to a third embodiment.

[0034] Fig.12 This is a first block diagram showing the configuration of a power conversion device according to a fourth embodiment.

[0035] Fig.13 This is a second block diagram showing the configuration of the power conversion device according to the fourth embodiment.

[0036] Fig.14 This is a flowchart for explaining the first relay switching operation when a failure of a switching element of the power conversion device according to the fourth embodiment is detected.

[0037] Fig.15 This is a flowchart for explaining the second relay switching operation when a failure of a switching element of the power conversion device according to the fourth embodiment is detected.

[0038] Fig.16 This is a schematic block diagram showing a configuration of an arm drive signal switching unit of a power conversion device according to a fifth embodiment.

[0039] Fig.17 This is a block diagram showing a configuration of an arm drive signal switching unit of a power conversion device according to a fifth embodiment.

[0040] Fig.18 This is a timing chart for explaining the operation when a failure of a switching element of the power conversion device according to the fifth embodiment is detected.

[0041] Fig.19 This is a block diagram showing the configuration of an arm drive signal switching unit of a power conversion device according to a sixth embodiment.

[0042] Fig. 20 This is a timing chart for explaining the operation when a failure of a switching element of the power conversion device according to the sixth embodiment is detected. DETAILED DESCRIPTION

[0043] Implementation

[0044] Hereinafter, the embodiments of the power conversion device involved in the present application will be described with reference to the accompanying drawings. As the purpose of the power conversion device, in embodiments 1 to 6, examples of controlling a three-phase AC motor and a two-phase AC motor are described. The technology of the power conversion device involved in the present application can be applied not only to a DC-AC conversion device, but also to the arm of a power conversion device in various fields represented by a DC-AC-DC conversion device and an AC-DC device.

[0045] 1. Implementation Method 1

[0046] Figure 1 This is a block diagram showing the configuration of the power conversion device 1 according to the first embodiment. Figure 2 This is a diagram showing a first example of a contact portion of a relay in the power conversion device 1 according to the first embodiment. Figure 3 This 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. Figure 4 1 is a diagram showing a hardware configuration of the control device 100 of the power conversion device 1 according to the first embodiment. Figure 5 This is a flowchart for explaining the relay switching operation when a failure of a switching element of the power conversion device 1 according to the first embodiment is detected. Figure 6 This is a timing chart for explaining the operation of the power conversion device 1 according to the first embodiment when a failure of the switching element is detected. Figure 7 This is a diagram showing the register 51 in the storage device 91 for the current control unit 10 of the power conversion device 1 according to the first embodiment.

[0047] <Structure of Power Conversion Device>

[0048] Hereinafter, the components and functions of the power conversion device 1 according to the first embodiment will be described. Figure 1 The power conversion device 1 is connected to a DC power source 2 and a rotating electric machine 3 , and has a function of converting DC power obtained from the DC power source 2 into AC power and controlling the rotation and torque of the rotating electric machine 3 .

[0049] 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 , a switching element 4 , a relay control unit 8 , a fault detection unit 9 , and a current control unit 10 .

[0050] The power conversion device 1 has a first arm 80 to a fourth arm 83 that connect two switching elements 4 in series. The number of the arms is calculated by adding 1 to the number of phases N ( Figure 1The number (N+1) obtained after (N=3) is added. The positive side switch element 4 is connected to the positive side of the DC power supply 2, and the negative side switch element 4 is connected to the negative side of the DC power supply 2. The positive side switch element 4 and the negative side switch element 4 are connected in series through the first wiring 41. An external connection point 44 is provided on the first wiring 41, and the outputs of the positive side switch element 4 and the negative side switch element 4 are transmitted to the outside. The positive side switch element 4 is sometimes referred to as the upper bridge arm, and the negative side switch element 4 is sometimes referred to as the lower bridge arm. The arm portion is composed of the positive side switch element 4, the negative side switch element 4 and the first wiring 41. Two relays are respectively provided between the external connection points 44 of adjacent arms from the first arm 80 to the fourth arm 83 configured in parallel, and a total of six (2N) relays are provided. The external connection points 44 of adjacent arms are connected by a second wiring 42 for connecting two relays in series. There is a third wiring 43, which is respectively connected to an output point 45 of a portion provided between two relays connected in series of the second wiring 42 and three connection terminals 46 of the winding of the rotating electric machine 3. Specifically, the output point 45 between the first relay 5 and the second relay 6, the output point 45 between the third relay 15 and the fourth relay 16, and the output point 45 between the fifth relay 17 and the sixth relay 18 are connected to the connection terminal 46 of the winding of the rotating electric machine 3.

[0051] Here, in Figure 1 In the embodiment, 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, the fourth arm 83, the fourth relay 16, the fifth relay 17 and the sixth relay 18 also form a module 7. Since the electronic circuit can be standardized by treating the switching element 4, the relay and its wiring as a module, the efficiency of designing and manufacturing the power conversion device 1 can be improved.

[0052] As the switching element 4, for example, a MOS-FET (metal oxide semiconductor field effect transistor) and an IGBT (insulated gate bipolar transistor) can be considered. Figure 2 As shown, the first to sixth relays 5 to 18 may be mechanical relays that open and close the mechanical contact portion 11 by causing current to flow from the control terminal 12 to the coil winding. Figure 3 As shown, a structure of an electronic relay using two MOS-FETs 40 connected in series as a semiconductor switch can be considered so that the parasitic diodes are in opposite directions to each other.

[0053] If an element made of a wide bandgap semiconductor is used as a MOS-FET in a switch element 4 or an electronic relay, and the wide bandgap semiconductor uses a silicon carbide or gallium nitride material, the switch element 4 or the electronic relay can be applied to a power conversion device 1 that uses a high voltage for a DC power supply 2. In addition, by utilizing the characteristic of being able to be used at high temperatures, the cooling structure of the MOS-FET 40 is simplified, and the power conversion device 1 can be miniaturized.

[0054] The fault detection unit 9 has a function of detecting a short-circuit fault or an open fault of the switching element 4 constituting the arm and notifying the arm of the fault. Various specific structures and methods of fault detection are proposed, and these techniques can be applied. The hardware structure is described below.

[0055] The current control unit 10 has a function of outputting an alternating signal to the switching element 4 constituting the arm according to the rotation speed and rotation torque of the rotary motor 3. In addition, as described later, it has a function of switching the drive signal of the arm according to the coil winding terminal of the rotary motor 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 to the coil winding of the rotary motor 3.

[0056] <Control device>

[0057] The relay control unit 8 , the fault detection unit 9 , and the current control unit 10 are functional blocks of the control device 100 . Figure 4 1 is a diagram showing a hardware structure of the control device 100 of the power conversion device 1 according to Embodiment 1. In this embodiment, each function of the control device 100 is implemented by a processing circuit included in the control device 100. Specifically, Figure 4 As shown, the control device 100 includes an operation processing device 90 (computer) such as a CPU (Central Processing Unit), a storage device 91 for exchanging data with the operation processing device 90, an input circuit 92 for inputting external signals to the operation processing device 90, and an output circuit 93 for outputting signals from the operation processing device 90 to the outside, etc., as processing circuits.

[0058] The operation processing device 90 may include an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, and various signal processing circuits. In addition, the operation processing device 90 may include a plurality of operation processing devices of the same type or a plurality of operation processing devices of different types, which share and execute various processes. The storage device 91 may include a RAM (Random Access Memory) configured to read and write data from the operation processing device 90, a ROM (Read Only Memory) configured to read data from the operation processing device 90, a flash memory, and the like. The input circuit 92 is connected to various sensors and switches, and includes an A / D converter, etc., which inputs the output signals of these sensors and switches to the operation processing device 90. The output circuit 93 is connected to an electric load, and includes a drive circuit, etc., which converts the control signal from the operation processing device 90 and outputs it to these electric loads.

[0059] The arithmetic processing unit 90 executes the software (program) stored in the storage device 91 such as ROM, and cooperates with other hardware of the control device 100 such as the storage device 91, the input circuit 92, and the output circuit 93, thereby realizing various functions of the control device 100. In addition, setting data such as threshold values ​​and judgment values ​​used by the control device 100 are stored in the storage device 91 such as ROM as part of the software (program).

[0060] right Figure 1 The functions of the components of the control device 100 will be described. Figure 1 The functions of the relay control unit 8, the fault detection unit 9, and the current control unit 10 described in the control device 100 may be respectively constituted by software modules or may be constituted by a combination of software and hardware.

[0061] Here, the relay control unit 8, the fault detection unit 9, and the current control unit 10 are described as functional blocks executed in the control device 100, but they may be independently provided as dedicated control devices.

[0062] <Processing Flowchart>

[0063] Figure 5FIG. 1 is a flowchart showing the relay switching operation of the relay control unit 8 of the power conversion device 1 according to the first embodiment. Figure 5 1 and 2 to specifically illustrate the relay switching action of the relay control unit 8 of the power conversion device 1. The relay control unit 8 turns on or off six (2N) relays so that the external connection point 44 of one arm is connected to each connection terminal 46 of each phase. The external connection point 44 of each arm can be connected to a specific one or two connection terminals 46 of the winding as a power supply target.

[0064] The relay control unit 8 turns on the first relay 5, the third relay 15, and the fifth relay 17, and in a state where the first arm 80 to the third arm 82 are electrically connected to the rotating electric machine 3, it is assumed that the fault detection unit 9 determines that any one of the first arm 80 to the third arm 82 has a fault. Starting from step S99, in step S100, the fault detection unit 9 determines which arm of the first arm 80 to the third arm 82 has a fault. Since the fourth arm 83 is not used, the case of the fault of the fourth arm 83 is not included. The second relay 6, the fourth relay 16, and the sixth relay 18 are in an open state.

[0065] When the failure detection unit 9 detects a failure in the third arm unit 82, the process proceeds to step S101. When the failure detection unit 9 detects a failure in the second arm unit 81, the process proceeds to step S103. When the failure detection unit 9 detects a failure in the first arm unit 80, the process proceeds to step S105.

[0066] When the third arm 82 fails, in step S101, the fifth relay 17 connected to the external connection point 44 of the third arm 82 where the failure occurs is turned off and electrically separated from the coil winding, and the process proceeds to step S102. In step S102, the sixth relay 18 connected to the external connection point 44 of the fourth arm 83 is turned on, and the process proceeds to step S109 to end the relay switching process.

[0067] When the second arm 81 fails, in step S103, the third relay 15 connected to the external connection point 44 of the second arm 82 where the failure occurs is disconnected and electrically separated from the coil winding, and the process proceeds to step S104. In step S104, the conduction and disconnection (output inversion) of the fourth relay 16 connected to the external connection point 44 of the arm where the failure does not occur to the sixth relay 18 are switched, and the process proceeds to step S109, and the switching process of the relay is ended.

[0068] When the first arm 80 fails, in step S105, the first relay 5 is disconnected and electrically separated from the coil winding, and the process proceeds to step S106. In step S106, the conduction and disconnection from the second relay 6 to the sixth relay 18 are switched (the output is reversed), and the process proceeds to step S109, and the switching process of the relay is terminated. As described above, the relay control unit 8 disconnects the relay directly connected to the external connection point 44 of the arm in which the fault is detected by the fault detection unit 9, and turns on or off the relay so that the external connection point 44 of the normal arm is respectively connected to the connection terminal 46 of the winding.

[0069] <Timing Diagram>

[0070] Figure 6 is with Figure 5 The timing chart of an example of the switching period of the drive signal of the arm part by the current control part 10 is shown in conjunction with the relay switching of the relay control part 8 shown in FIG. Figure 6 The relay switching operation of the power conversion device 1 is specifically described with reference to the timing chart shown.

[0071] exist Figure 6 At time t1, the fault detection unit 9 detects the fault of the first arm 80 and notifies the detected fault content to the outside of the fault detection unit 9. The relay control unit 8 receives the fault content detected and notified by the fault detection unit 9, and implements the switching action of the relay according to the fault content. Since the fault content at time t1 is the fault of the first arm 80, the relay control unit 8 performs the switching action of the relay according to the fault content. Figure 5 The process in the flowchart shown switches the first relay 5 from on to off at time t2.

[0072] Thereafter, the relay control unit 8 waits for a prescribed time to pass, and at time t3, reverses the conduction and disconnection from the second relay 6 to the sixth relay 18, and ends the switching action of the relay. Here, at time t3, in the switching between the conduction and disconnection of the relay (reversing the output), the disconnection is first performed, and the conduction is performed after a prescribed delay time, that is, the conduction delay time. As the delay time, for example, a method of precalculating or measuring the transition time of the relay actually switching to the disconnection after receiving the disconnection instruction, and setting the time as the delay time can be considered. By setting the delay time, the opportunity of 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 connected to the same coil terminal being turned on at the same time can be avoided, and the erroneous short circuit of the arm caused by the power conversion action in the state where 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, in the state where the terminals of the coil winding are short-circuited, can be reliably prevented.

[0073] After the relay switching action of the relay control unit 8 is completed, the current control unit 10 switches the drive signals of the respective arms at time t4 based on the on and off states of the first to sixth relays of the relay control unit 8, and the power conversion device 1 can perform the power conversion action again. As a method for the current control unit 10 to switch the drive signals of the respective arms, for example, Figure 7 As shown in FIG. 1 , a method of presetting the register 51 of the storage device 91 in the control device 100 according to the coil winding terminal of the rotating electrical machine and changing the arrangement of the register 51 according to the switching of the relay may be considered. Figure 4 The arithmetic processing unit (CPU) 90, storage device 91, input circuit 92 and output circuit 93 are integrated into a single chip microcomputer, and the register 51 of the storage device 91 in the microcomputer is used.

[0074] In the first embodiment, N+1 arms are provided, which are obtained by adding 1 to the number of phases N of the winding of the rotating electric machine 3. The arm is composed of a positive-side switching element 4 connected to the positive side of the DC power supply 2, a first wiring 41 connected in series and provided with an external connection point 44. The order of the N+1 arms is numbered, and two relays are respectively provided between the external connection points 44 of two adjacent numbered arms, and a total of 2N relays are provided. A second wiring 42 is provided, and the second wiring 42 is connected between the external connection points 44 of the two adjacent numbered arms through two relays connected in series. In the power conversion device 1, an output point 45 is provided in a portion between the relays connected in series of the second wiring 42, and a third wiring is provided to connect each output point 45 to each connection terminal 46 of the winding of the rotating electric machine 3. Since power can be supplied to the connection terminal 46 of the coil of one specific system or any one of the connection terminals 46 of the coils of two specific systems via two relays, the arm used in general has the function of a redundant arm. The arm where the abnormality is detected can be disconnected, and the relay can be switched to connect the arm on standby as a redundant arm to continue the power conversion operation.

[0075] Since only the connection to the connection terminal 46 of a specific coil winding is switched for each arm, and the drive signal of the arm is switched according to the switching state of the relay, it is possible to avoid switching target errors.

[0076] Since the arm portion formed by the switching element 4 also has the function of a redundant arm and is capable of supplying power to the connection terminal 46 of any one of the windings of one or two systems of the rotating motor 3 via a relay, the arm portions of each phase including the relay and the redundant arm can be standardized and modularized, and the cost of additional structure of the redundant arm can be reduced.

[0077] Since the arm also functions as a redundant arm and can be modularized, the wiring between the module arm and the coil winding terminals of the rotating electrical machine 3 can be simplified without crossing the wiring, and the power conversion device 1 can be miniaturized.

[0078] Furthermore, the wiring distances from each arm to the connection terminals 46 of the windings of the rotating electrical machine 3 can be arranged to be equal, and the wiring impedance is also the same, so that even after a failure of the arm occurs, the level of heat generation and radiation noise of the power conversion device does not change. In addition, current interference between coil windings does not occur, and the wiring of the switched arm becomes longer, so that the conduction and disconnection of the switching element are not delayed in current control, and the power conversion operation can be continued.

[0079] exist Figure 5 , the relay switching action when a fault occurs in a state where 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 rotating motor 3 is described. However, in the present embodiment, this is not limited to this, and even when a fault 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 rotating motor 3 (the first relay 5, the third relay 15, and the fifth relay 17 are disconnected), the power conversion action can be continued by the relay switching action. That is, by Figure 5 The third arm 82 in the flowchart is replaced by the second arm 81, the second arm 81 is replaced by the third arm 82, the first arm 80 is replaced by the fourth arm 83, the processing of step S101 is applied to the second relay 6, the processing of step S102 is applied to the first relay 5, the processing of step S103 is applied to the second relay 6, the processing of step S104 is applied from the first relay 5 to the third relay 15, the processing of step S105 is applied to the sixth relay 18, and the processing of step S106 is applied from the first relay 5 to the fifth relay 17, so that corresponding operations can be performed.

[0080] 2. Implementation Method 2

[0081] Figure 8 This is a flowchart for explaining the operation of the control device when a failure of a switching element of the power conversion device 1 according to the second embodiment is detected. Fig. 9 This is a flowchart for explaining the relay switching operation when a failure of a switching element of the power conversion device according to the second embodiment is detected. Fig.10 This is a timing chart for explaining the operation when a failure of a switching element of the power conversion device according to the second embodiment is detected.

[0082] In the first embodiment, the case where there is no induced current in the coil winding of the rotating electric machine 3 is described. In the second embodiment, it is not limited to this, and there may be induced current in the coil winding, and the same effect can be obtained by designing the switching method of the relay. For example, Figure 8 , the relay switching operation when the induction current flows through the coil winding of the rotating electric machine 3 as the power conversion device 1 of the second embodiment is shown. Figure 1 The operation is described below. 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 rotating electric machine 3, on the premise that the fault detection unit 9 determines that any one of the first arm 80 to the third arm 82 has a fault. The second relay 6, the fourth relay 16, and the sixth relay 18 are in the disconnected state.

[0083] The process starts from step S199. In step S200, the fault detection unit 9 determines whether a fault occurs in the arm. If a fault occurs, the process proceeds to step S201. If no fault occurs, the relay switching action is not performed, and the process proceeds to step S209 and ends. In step S201, in order to stop the current control, the current control unit 10 stops the drive of all arms and proceeds to step S202. In step S202, the relay control unit 8 performs the relay switching action according to the fault content and proceeds to step S203. The relay switching action in step S202 is based on the following description. Fig. 9 The flowchart shown is used for implementation.

[0084] 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 and off states of the first relay 5 to the sixth relay 18 of the relay control unit 8, switches the arm drive signal, and proceeds to step S204. In step S204, in order to restart the current control, the current control unit 10 restarts the drive of the arm, and proceeds to step S209, ending the switching process of the relay caused by the failure of the arm.

[0085] As a method for detecting the flow of induced current in the coil winding, for example, a method of using a coil current detection unit (not shown) for detecting the coil current for the purpose of controlling the rotation and torque of the rotating motor 3 can be considered. Various specific structures and methods for current detection have been proposed, and these technologies can be applied, so the description is omitted here. In addition, as a method for detecting the flow of induced current to the coil winding of the rotating motor 3, a method of measuring the voltage of the coil winding terminal of the rotating motor 3 and detecting the induced voltage of the coil winding terminal generated by the induced current can be considered. Therefore, an induced voltage detection unit for detecting the induced voltage by measuring the coil winding voltage can be set, and when the induced voltage is detected, the relay control unit 8 can first perform the on control while reversing the on and off of the relay, and implement the off control after a specified delay time, that is, the off delay time. Since various specific structures and methods for voltage detection have been proposed, and these technologies can be applied, the description is omitted here.

[0086] Alternatively, when the rotating motor 3 rotates at a high speed, it can be determined that an induced current is generated. The rotating speed of the rotating motor 3 can be obtained by a rotating speed detector, and when the rotating speed is above a predetermined determining rotating speed, the relay switching operation of the relay control unit 8 is first performed when a failure of the arm is detected, and when the conduction and disconnection of the relay are reversed, the conduction control is first performed, and the disconnection control is performed after the disconnection delay time has passed. The optimal value of the determination rotation speed can be obtained by experiment.

[0087] Fig. 9 1 is a flowchart showing the relay switching operation of the relay control unit 8 of the power conversion device 1 according to the second embodiment. Fig. 9 The relay switching operation of the relay control unit 8 of the power conversion device 1 will be specifically described with reference to the flowchart shown.

[0088] The relay control unit 8 turns on the first relay 5, the third relay 15, and the fifth relay 17, and electrically connects the first arm 80 to the third arm 82 to the rotating electric machine 3, on the premise that the fault detection unit 9 determines that a fault has occurred in any one of the first arm 80 to the third arm 82. The process starts from step S209, and in step S210, the fault detection unit 9 determines which arm has detected a fault from the first arm 80 to the third arm 82. Since the fourth arm 83 is not used, the fourth arm 83 is excluded from the fault object.

[0089] When the failure detection unit 9 detects a failure in the third arm unit 82, the process proceeds to step S211. When the failure detection unit 9 detects a failure in the second arm unit 81, the process proceeds to step S213. When the failure detection unit 9 detects a failure in the first arm unit 80, the process proceeds to step S215.

[0090] When the third arm 82 fails, 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 third arm 82 where the failure occurs is disconnected, so that the third arm 82 where the failure occurs is electrically separated from the coil winding, and the process proceeds to step S219 to end the relay switching process.

[0091] When the second arm 81 fails, in step S213, the on and off of the fourth relay 16 to the sixth relay 18 connected to the external connection point 44 of the other arm that has not failed is switched (the output is reversed), and the process proceeds to step S214. In step S214, the third relay 15 connected to the external connection point 44 of the second arm 81 that has failed is disconnected, the second arm 81 is electrically separated from the coil winding, and the process proceeds to step S219 to end the relay switching process.

[0092] When the first arm 80 fails, in step S215, the conduction and disconnection from the second relay 6 to the sixth relay 18 are switched (the output is reversed), and the process proceeds to step S216. In step S216, the first relay 5 is disconnected, the first arm 80 is electrically separated from the coil winding, and the process proceeds to step S219, and the switching process of the relay is ended.

[0093] Fig.10 is with Fig. 9 The timing chart of an example of the switching period of the drive signal of the arm of the current control unit 10 is shown in conjunction with the relay switching of the relay control unit 8 shown in FIG. Fig.10 The relay switching operation of the power conversion device 1 is specifically described with reference to the timing chart shown.

[0094] exist Fig.10 At time t10, the fault detection unit 9 detects the fault of the first arm and notifies the detected fault content to the outside of the fault detection unit 9. In addition, the relay control unit 8 receives the fault content detected and notified by the fault detection unit 9, and implements the switching action of the relay according to the fault content. Since the fault content at time t10 is the fault of the first arm, the relay control unit 8 performs the switching action according to the fault content. Figure 8 The process of the flowchart shown switches the second to sixth relays on and off at time t11.

[0095] The relay control unit 8 switches the first relay 5 from on to off at time t12, and ends the switching operation of the relay. In addition, since the coil winding terminals are in a short-circuit state from t11 to t12, and regenerative braking occurs in the rotating electric machine 3, the corresponding relay is first turned on at t11, and then the relay switched from on to off is quickly turned off, so that the occurrence of regenerative braking is suppressed to a minimum, thereby suppressing the rotation variation of the rotating electric machine 3 to a minimum.

[0096] After the relay switching operation of the relay control unit 8 is completed, the current control unit 10 updates the allocation of the coil terminals of each arm at time t13 based on the on and off states of the first relay 5 to the sixth relay 18 of the relay control unit 8, and switches the drive signal. In the power conversion device 1, the current control unit 10 restarts the current control from time t14. That is, the power conversion operation of the power conversion device 1 can be performed again.

[0097] As described above, in the second embodiment, similarly to the first embodiment, the arm parts composed of the switching elements 4 connected to the DC power supply 2 are provided with N+1 phases obtained by adding 1 to the number of phases N of the winding of the rotating electric machine 3. The positive-side switching element 4 connected to the positive side of the DC power supply 2 and the negative-side switching element 4 connected to the negative side of the DC power supply 2 are connected in series through the first wiring 41, and the external connection point 44 is provided in the first wiring 41. For the N+1 arms arranged in parallel, the external connection points 44 of the adjacent arms are connected in series through the second wiring 42 via two relays. In the power conversion device 1, each output point 45 of the part provided between the two relays of the second wiring 42 is connected to the connection terminal 46 of the winding of the rotating electric machine 3 through the third wiring 43. Since each arm can supply power to any of the connection terminals 46 of the winding of a specific one or two systems through the relay, each arm also has the function of a redundant arm, and the arm in which an abnormality is detected can be disconnected, and the power conversion operation can be continued by switching the relay.

[0098] Since the arm is switched so as to be connectable 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 a switching destination error.

[0099] Since the arm portion formed by the switching element 4 also has the function of a redundant arm and is capable of selectively supplying power to the connection terminal 46 of the windings of two different systems of the rotating motor 3 via two relays, the arm portions of each phase including the relays and the redundant arm can be standardized and modularized, and the cost of additional structure of the redundant arm can be reduced.

[0100] Since the normal arm 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 rotating electric machine 3 can be simplified without crossing the wiring, and the power conversion device 1 can be miniaturized.

[0101] In addition, the wiring distances from each arm to the connection terminals 46 of the windings of the rotating motor 3 can be configured to be equal. If the wiring impedance is matched, the heat generation and radiation noise of the power conversion device will not change even after a failure of the arm, and the power conversion action can continue without generating current interference between the coil windings.

[0102] exist Fig. 9 , the relay switching action when a fault occurs in a state where the relay control unit 8 turns on the first relay 5, the third relay 15, and the fifth relay 17 and electrically connects to the rotating motor 3 is described, however, in this embodiment, it is not limited to this, and 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 rotating motor 3 (the first relay 5, the third relay 15, and the fifth relay 17 are disconnected), even if a fault occurs, the power conversion action can be continued by the relay switching action. That is, by Fig. 9 The third arm 82 in the flowchart is replaced by the second arm 81, the second arm 81 is replaced by the third arm 82, the first arm 80 is replaced by the fourth arm 83, the processing of step S211 is applied to the first relay 5, the processing of step S212 is applied to the second relay 6, the processing of step S213 is applied from the second relay 5 to the third relay 15, the processing of step S214 is applied to the second relay 6, the processing of step S215 is applied from the first relay 5 to the fifth relay 17, and the processing of step S216 is applied to the sixth relay 18, so that corresponding operations can be performed.

[0103] When the induced current flows through the coil winding of the rotating electric machine 3, the relay control unit 8 first conducts the relay in the relay switching action, thereby avoiding the jump of the induced voltage caused by the disconnection of the current path, and suppressing the influence of the rotation change of the rotating electric machine 3 due to the relay switching to the minimum. An induced voltage detection unit that detects the induced voltage by measuring the coil winding voltage can be provided, and when the induced voltage is detected, the relay control unit 8 can first perform the on control while reversing the on and off of the relay, and perform the off control after the off delay time. In addition, when the rotating electric machine 3 rotates at a high speed, it can be determined that the induced current is generated, so the rotation speed of the rotating electric machine 3 is obtained by the rotation speed detector, and when the rotation speed is above the judgment rotation speed, when the arm failure is detected, the relay switching action of the relay control unit 8 can be implemented in the following manner: when the on and off of the relay are reversed, the on control is first performed, and the off control is performed after the off delay time. Since the relay is turned on first, a jump in the induced voltage due to the disconnection of the current path can be avoided, and the influence of the switching of the relay on the rotation variation of the rotating electric machine 3 can be suppressed to a minimum.

[0104] When a fault of the switching element 4 is detected during the process of supplying power to the rotating electrical machine 3, the power conversion device 1 stops the drive of the arm before the switching action of the relay, thereby avoiding an erroneous short circuit of the arm caused by the switching of the relay. In particular, when the relay control unit 8 connects a plurality of arms to the same winding terminal, the current control unit 10 stops the current control, which is of great significance for preventing new faults in the arm. In addition, here, in the power conversion device 1 as a driving device for the rotating electrical machine 3, a current detection unit is provided in the winding, the winding current is detected, and current feedback control is performed in many cases. Even in the case where the fault detection unit 9 detects a fault when the current is detected by the current detector, the current control of the current control unit 10, that is, the drive of the arm, is stopped, and then the relay control unit 8 switches the relay on and off. Therefore, it is of great significance for preventing new faults in the arm.

[0105] 3. Implementation Method 3

[0106] Fig.11 1 is a block diagram showing the structure of a power conversion device 1 according to Embodiment 3. The power conversion device 1 according to Embodiment 3 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, a switching element 4, a relay control unit 8, a fault detection unit 9, and a current control unit 10.

[0107] Compared with the structure of the previous embodiment 1 Figure 1 The scope of modularity is different. Fig.11 In the module 70 shown, an arm portion connecting two switching elements 4 in series is connected to a DC power source 2, and an external connection point 44 of the two switching elements 4 constituting the arm portion is connected to a connection terminal 46 of windings of two different systems of the rotating electric machine 3 via two relays. Fig.11 In the embodiment, the module 70 is formed by the second arm 81, the second relay 6, and the third relay 15, and the third arm 82, the fourth relay 16, and the fifth relay 17, respectively.

[0108] In addition, another module 71 has two arms connected in parallel, and the external connection points 44 of the two switching elements 4 constituting the arms are independent of each other and are connected to the connection terminals 46 of the windings of two different systems of the rotating electric machine 3 via relays, respectively. Fig.11 In the embodiment, the first arm 80 , the fourth arm 83 , the first relay 5 and the sixth relay 18 form a module 71 .

[0109] The relay control unit 8, the fault detection unit 9 and the current control unit 10 are connected to Figure 1 The same, therefore the description is omitted.

[0110] Fig.11 The basic form of the power conversion device 1 shown has a module 70 and another module 71, and the necessary number of the modules 70 is increased or decreased according to the number of connection terminals of the windings of the rotating electrical machine 3. Since the number of modules 70 can be increased or decreased relative to the increase or decrease in the number of connection terminals of the windings of the rotating electrical machine, the efficiency in design and manufacturing can be improved, and it can contribute to cost reduction.

[0111] 4. Implementation Method 4

[0112] Fig.12 This is a first block diagram showing the configuration of the power conversion device 31 according to the fourth embodiment. Fig.13 This is a second block diagram showing the configuration of the power conversion device 31 according to the fourth embodiment. Fig.14 This is a flowchart for explaining the first relay switching operation when a failure of a switching element of the power conversion device 31 according to the fourth embodiment is detected. Fig.15 This is a flowchart for explaining the second relay switching operation when a failure of a switching element of the power conversion device 31 according to the fourth embodiment is detected.

[0113] Fig.12 FIG. 1 is a block diagram for explaining the configuration of the power conversion device 31 when the rotating electric machine 33 is a two-pole rotating electric machine. Even in the case of the two-pole rotating electric machine 33, similarly to the case of the three-pole rotating electric machine 33, by increasing the number of phases N ( Fig.12 N = 2) plus 1 and set N + 1 ( Fig.12There are 3) arms. The positive-side switching element 4 connected to the positive side of the DC power supply 2 and the negative-side switching element 4 connected to the negative side of the DC power supply 2 are connected in series via a first wiring 41, and an external connection point 44 is provided in the first wiring 41. For the N+1 arms configured in parallel, the external connection points 44 of adjacent arms are connected in series via two relays and through a second wiring 42. In the power conversion device 31, each output point 45 of the portion provided between the two relays of the second wiring 42 is respectively connected to a connection terminal 46 of the winding of the rotating motor 3 through a third wiring 43. Since each arm can supply power to any of the connection terminals 46 of the winding of a specific one or two systems via a relay, each arm also has the function of a redundant arm, can disconnect the arm in which an abnormality is detected, and can continue the power conversion action by switching the relay.

[0114] The relay control unit 38, the fault detection unit 39, and the current control unit 30 are described as functions of the control device 101. The control device 101 adopts the same method as that of the first to third embodiments. Figure 1 , 3 11. The first to fourth relays 5 to 16 are turned on and off by the relay control unit 38, and the first to third arms 80 to 82 are distributed to the winding terminals of the rotary electric machine 33.

[0115] Fig.13 A second block diagram showing another structure of the power conversion device 31 is shown in FIG. Fig.13 and Fig.12 The circuits are the same, but the configurations of the first arm 80 to the third arm 82 are different. Fig.13 By configuring the module 70 and the other module 71, the same functions and effects as those of the previous embodiments 1 and 2 can be achieved. These modules 70 and 71 are the components of the embodiment 3. Fig.11 Therefore, by modularizing the circuit components, the same modules can be used regardless of whether the terminals of the rotating electric machine 33 are two terminals or three terminals, thereby contributing to reducing the costs of both design and manufacturing through standardization.

[0116] exist Fig.13 In the embodiment, 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 form another module 71 .

[0117] Fig.14 The power conversion device 31 of the fourth embodiment is connected to the bipolar rotating electric machine 33. Fig.12The structure shown in FIG. 1 is an object, and a flowchart of the relay switching operation of the relay control unit 38 is shown in FIG. Fig.14 1 and 2 to specifically illustrate the relay switching action of the relay control unit 38 of the power conversion device 31. The relay control unit 38 turns on or off four (2N) relays so that the external connection point 44 of one arm is connected to each connection terminal 46 of each phase. The external connection point 44 of each bridge arm can be connected to one or two specific connection terminals 46 of the winding as a power supply target.

[0118] It is assumed that the fault detection unit 39 detects a fault in a state where the relay control unit 38 turns on the first relay 5 and the third relay 15 and electrically connects the rotating electric machine 33. Starting from step S299, in step S300, it is determined whether the fault detection unit 39 detects a fault in any one of the first arm 80 and the second arm 81. The second relay 6 and the fourth relay 16 are in the off state.

[0119] When the failure detection unit 39 detects a failure in the second arm unit 81, the process proceeds to step S301. When the failure detection unit 39 detects a failure in the first arm unit 80, the process proceeds to step S303.

[0120] 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 second arm 81 where the failure occurs is disconnected, and the second arm 81 where the failure occurs is electrically separated from the coil winding, and the process proceeds to step S302. In step S302, the conduction and disconnection of the first relay 5 and the fourth relay 16 connected to the external connection point 44 of the other arms where the failure occurs are switched, and the process proceeds to step S309 to end the relay switching process.

[0121] When a failure of the first arm 80 is detected, in step S303, the first relay 5 is disconnected, and the first arm 80 is electrically separated from the coil winding, and the process proceeds to step S304. In step S304, the conduction and disconnection of the second relay 6 to the fourth relay 16 are switched, and the process proceeds to step S309 to end the relay switching process. As described above, the relay control unit 38 disconnects the relay directly connected to the external connection point 44 of the arm part where the failure is detected by the fault detection unit 39, and turns on or off the relay so that the external connection point 44 of the normal arm part is respectively connected to the connection terminal 46 of the winding.

[0122] and Fig.14 The timing chart showing an example of the switching period of the drive signal of the arm portion of the current control unit 30 in accordance with the relay switching of the relay control unit 38 shown in FIG. Figure 6 The same, therefore the description is omitted.

[0123] In addition, there may be an induced current in the coil winding by applying the above Figure 8 The relay switching operation when an induced current flows through the coil winding of the rotating electric machine 33 shown in FIG. Fig.15 The same effect can be obtained by switching the relays of the relay control unit 38 in the flowchart shown in FIG.

[0124] Fig.15 The power conversion device 31 of the fourth embodiment is connected to the bipolar rotating electric machine 33. Fig.13 The structure shown in FIG. 1 is a flow chart of the relay switching operation of the relay control unit 38 when an induced current flows through the coil winding of the rotating motor 33. Fig.15 The flowchart shown in FIG. 1 specifically describes the relay switching operation of the relay control unit 38 of the power conversion device 31 .

[0125] It is assumed that the fault detection unit 39 determines that the first arm 80 or the second arm 81 has a fault when the relay control unit 38 turns on the first relay 5 and the third relay 15 and electrically connects the rotating motor 33. Starting from step S399, in step S400, it is determined which of the first arm 80 and the second arm 81 the fault detection unit 39 has detected. Since the third arm 82 is not used, the third arm 82 is excluded from the object. Although the fault detection unit 39 detects a fault, if it is the second arm 81, the process proceeds to step S401. If the fault is detected in the first arm 80, the process proceeds to step S403.

[0126] In the case where the second arm 81 fails, in step S401, the first relay 5 and the fourth relay 16 connected to the external connection point 44 of the other arm that has not failed are switched on and off in reverse order, and the process proceeds to step S402. In step S402, the third relay 15 connected to the external connection point 44 of the second arm 81 that has failed is disconnected, and the second arm 81 is electrically separated from the coil winding, and the process proceeds to step S409, and the relay switching process ends. In the case where the first arm 80 fails, in step S403, the second relay 6 to the fourth relay 16 are switched on and off in reverse order, and the process proceeds to step S404. In step S404, the first relay 5 is disconnected and electrically separated from the coil winding, and the process proceeds to step S409, and the relay switching process ends.

[0127] and Fig.15 The timing chart showing an example of the switching period of the drive signal of the arm portion of the current control unit 30 in accordance with the relay switching of the relay control unit 38 shown in FIG. Fig.10 The same, therefore the description is omitted.

[0128] As described above, in Embodiment 4, since power can be supplied to any of the connection terminals 46 of the coils of a specific one or two systems via two relays, the arm used normally also functions as a redundant arm. The arm in which an abnormality is detected can be disconnected, and the relay can be switched to connect the arm on standby as a backup redundant arm, and the power conversion operation can be continued.

[0129] Since the arm is switched so as to be connected only to a specific coil winding terminal and the drive signal of the arm is switched according to the switching state of the relay, it is possible to avoid a switching target error.

[0130] Since the arm portion formed by the switching element 4 also has the function of a redundant arm, and is a method of supplying power to the coil winding terminals of two different systems of the rotating electrical machine 3 via two relays, the arm portions of each phase including the relay and the redundant arm can be standardized and modularized, and the cost of adding a redundant arm structure can be reduced. In particular, the arm portion of this embodiment can be applied even if the rotating electrical machine 33 has two poles, so that regardless of the structure of the rotating electrical machine 33, the arm portions of each phase can be standardized and modularized, and the cost of adding a redundant arm structure can be further reduced.

[0131] Since the arm also functions as a redundant arm, wiring between the arm of the module and the coil winding terminals of the rotary electric machine 33 can be simplified without crossing, and the power conversion device 31 can be miniaturized.

[0132] In addition, the wiring distances from each arm to the coil winding terminals of the rotating motor 33 can be configured to be equal. If the wiring impedance is matched, the heat generation and radiation noise of the power conversion device will not change even after a failure of the arm, and the power conversion action can continue without generating current interference between the coil windings.

[0133] exist Fig. 9 In the embodiment, the relay switching action when a fault occurs is described in the state where the relay control unit 8 turns on the first relay 5 and the third relay 15 and electrically connects to the rotating motor 33. However, the present embodiment is not limited to this. In the state where the second relay 6 and the fourth relay 16 are turned on (in addition, the first relay 5 and the third relay 15 are turned off) and electrically connected to the rotating motor 33, even if a fault occurs, the power conversion action can be continued by the relay switching action. That is, Fig.14 The first arm 80 in the flowchart is replaced by the third arm 82 , the process of step S301 is applied to the second relay 6 , and the process of step S303 is applied to the fourth relay 16 .

[0134] Will Fig.15The first arm 80 in the flowchart is replaced by the third arm 82, the processing of step S402 is replaced by the second relay 6, and the processing of step S404 is replaced by the fourth relay 16, so that it can be handled.

[0135] When the induced current flows through the coil winding of the rotating motor 33, the relay control unit 38 first implements the conduction of the relay during the relay switching action, thereby avoiding the jump of the induced voltage caused by the disconnection of the current path and minimizing the impact of the rotation change of the rotating motor 33 caused by the switching of the relay.

[0136] When a failure of the switching element 4 is detected during the supply of power to the rotary electric machine 33 , the power conversion device 31 stops driving the arm before switching the relay, thereby preventing an erroneous short circuit of the arm due to switching of the relay.

[0137] 5. Implementation Method 5

[0138] Fig.16 This 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 This 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 This is a timing chart for explaining the operation when a failure of a switching element of the power conversion device according to the fifth embodiment is detected.

[0139] In the above-mentioned embodiments 1 to 4, when the relay is switched due to a failure of the arm, the current control unit 10 also switches the drive signal of the arm, but this is not limited to this in the present embodiment, and the drive signal of the arm can be switched at a position closer to the module 7. Fig.16 As shown, the structure of the power conversion device 1 in this embodiment 5 is in addition to the above Figure 1 In addition to the structure, an arm drive signal switching unit 20 is also included between the current control unit 10 and the module 7.

[0140] The arm drive signal switching unit 20 has a function of driving the gate of the switching element 4 constituting the arm of the module 7 by transmitting the arm drive signal output by the current control unit 10 to the module 7. In addition, 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, it is conceivable to have, for example, Fig.17 The structure shown. Fig.17 In the embodiment, the arm driving signal switching unit 20 includes a gate driving circuit 21 , a level shifter 22 , and a selector 23 .

[0141] The gate drive circuit 21 is a circuit for driving the gate of the switching element 4. Various specific structures and methods have been proposed, and these technologies can be applied, so the description is 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. Since various specific structures and methods have been proposed, and these technologies can be applied, the description is omitted here.

[0142] The selector 23 has a function of inputting drive signals for the arms of two different coil windings and transmitting the drive signal for the arm of any one coil winding to the arm of the module 7 according to the relay switching operation of the relay control unit 8. Fig.17 In the embodiment, since the first arm 80 and the fourth arm 83 supply power to only one system of coil windings, a selector is not required, however, the first arm 80 and the fourth arm 83 are provided with a selector 23, and by turning off one of the input signals of the selector 23 as a drive signal, the drive of the arm can be turned off by a switching control signal of the selector 23. In addition, the selector 23 has a three-state function, and the output of the selector 23 is set to high impedance according to a fault of the arm, thereby cutting off the drive signal of the arm.

[0143] For example, a method of inputting a switching control signal of the selector 23 from the current control unit 10 and the relay control unit 8 or providing a microcomputer and an ASIC in the arm drive signal switching unit 20 to control the selector 23 may be adopted.

[0144] Fig.18 is with Fig. 9 The timing chart of an example of the switching period of the arm drive signal of the arm drive signal switching unit 20 is shown in conjunction with the relay switching of the relay control unit 8 shown in FIG. Fig.18 The relay switching operation of the power conversion device 1 is specifically described with reference to the timing chart shown.

[0145] exist Fig.18 At time t20, the fault detection unit 9 detects a fault in the arm portion having only the first relay 5, and notifies the detected fault content to the outside of the fault detection unit 9. Furthermore, the relay control unit 8 receives the fault content detected and notified by the fault detection unit 9, and performs the switching action of the relay according to the fault content.

[0146] Since the fault content at time t20 is the fault of the first arm, the relay control unit 8 Figure 5The processing of the flowchart shown in the figure reverses the on and off of the second relay 6 to the sixth relay 18 at time t21. The relay control unit 8 switches the first relay 5 from on to off at time t22, and ends the switching operation of the relay. In addition, since the coil winding terminals are in a short-circuited state from time t21 to t22, and regenerative braking occurs in the rotating electric machine 3, the corresponding relay is first turned on at time t21, and then the relay switched from on to off is quickly turned off, so that the occurrence of regenerative braking is suppressed to a minimum, thereby suppressing the rotation variation of the rotating electric machine 3 to a minimum.

[0147] After the relay switching operation of the relay control unit 8 is completed, the arm drive signal switching unit 20 switches the drive signals of the arms through the selector 23 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 . Fig.18 An example is shown in which the drive signal of the first arm is turned off by the selector 23, the drive signal of the second arm is switched from the drive signal of the arm for the V-phase coil of the rotating electric machine 3 to the drive signal of the arm for the U-phase coil, the drive signal of the third arm is switched from the drive signal of the arm for the W-phase coil of the rotating electric machine 3 to the drive signal of the arm for the V-phase coil, and the drive signal of the fourth arm is switched from the off state to the drive signal of the arm for the W-phase coil of the rotating electric machine 3. Then, from time t24, the power conversion device 1 can perform the power conversion operation again.

[0148] As described above, in the fifth embodiment, the arm parts connected to the DC power supply and composed of the switching elements are provided, the number of the arm parts is the number obtained by adding 1 to the number of the coil winding terminals of the rotating electric machine, the adjacent external connection points 44 of the arms arranged in parallel 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 by using two of the three arms, each arm part has the function of a redundant arm, and the arm part in which an abnormality is detected can be disconnected, and the power conversion operation can be continued by switching the relay.

[0149] Since the arm is switched so as to be connected only to a specific coil winding terminal and the drive signal of the arm is switched according to the switching state of the relay, it is possible to avoid a switching target error.

[0150] Since the arm formed by the switching element 4 also has the function of a redundant arm and power is supplied to the coil winding terminals of two different systems via two relays, the arm portions of each phase including the relays and the redundant arm can be standardized and modularized, and the cost of additional structure of the redundant arm can be reduced.

[0151] Since the arm also functions as a redundant arm, wiring between the arm of the module 7 and the coil winding terminals of the rotary electric machine 3 can be simplified without crossing, and the power conversion device 1 can be miniaturized.

[0152] In addition, the wiring distances from each arm to the coil winding terminals of the rotating motor 3 can be configured to be equal. If the wiring impedance is matched, the heat generation and radiation noise of the power conversion device will not change even after a failure of the arm, and the power conversion action can continue without generating current interference between the coil windings.

[0153] When the induced current flows through the coil winding of the rotating motor 3, the relay control unit 8 first implements the conduction of the relay during the relay switching action, thereby avoiding the jump of the induced voltage caused by the disconnection of the current path and minimizing the impact of the rotation change of the rotating motor 3 caused by the relay switching.

[0154] When a failure of the switching element 4 is detected during the supply of power to the rotating electrical machine 3 , the power conversion device 1 stops driving the arm before the switching operation of the relay, thereby preventing an erroneous short circuit of the arm due to the switching of the relay.

[0155] 6. Implementation Method 6

[0156] Fig.19 1 is a block diagram showing a configuration of the arm drive signal switching unit 20 of the power conversion device 1 according to the sixth embodiment. Fig. 20 This is a timing chart for explaining the operation of the power conversion device 1 according to the sixth embodiment when a failure of a switching element is detected.

[0157] In Embodiment 5, when relay switching is performed due to arm failure, a method of switching the arm drive signal before inputting the level shifter 22 of the arm drive signal switching unit 20 is described. However, the present invention is not limited to this, and switching may be performed between the gate drive circuit 21 and the module 7 .

[0158] like Fig.16 As shown, the structure of the power conversion device 1 in this embodiment 6 is in addition to the above Figure 1 In addition to the structure, an arm drive signal switching unit 20 is also included between the current control unit 10 and the module 7. The arm drive signal switching unit 20 has a function of driving the gate of the switching element 4 constituting the arm of the module 7 by transmitting the arm drive signal output by the current control unit 10 to the module 7.

[0159] 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. The arm drive signal switching unit 20 may have, for example, Fig.19 The structure shown.

[0160] exist Fig.19 In the embodiment, 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 for driving the gate of the switching element 4, and various specific structures and methods have been proposed, and these technologies can be applied, so the description is omitted here.

[0161] 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. Since various specific structures and methods have been proposed and these technologies can be applied, the description is omitted here. For the purpose of taking measures corresponding to the abnormality of the power conversion device 1, the gate signal cut-off switching unit 24 has a function of cutting off the gate signal, and a gate cut-off unit 25 is provided, which is used to cut off the gate drive signal of the switching element 4 of the arm of the module 7.

[0162] As the gate cut-off portion 25, for example, Figure 2 As shown, a mechanical relay and a semiconductor relay using MOS-FET can be considered. In the on-off control of the gate cut-off unit 25, a host controller outside the power conversion device 1 or a sub-microcomputer or ASIC provided inside the power conversion device 1 monitors the power conversion operation of the power conversion device 1, and when an abnormality in the power conversion operation is detected, the gate cut-off unit 25 cuts off the gate signal.

[0163] In addition, the gate signal cutoff section 24 has a function of inputting gate drive signals of the switching elements 4 of the arms of two different coil windings of the rotating electric machine 3, and transmitting the gate drive signals of the switching elements 4 of the arms of any one coil winding to the arm of the module 7 according to the relay switching action of the relay control section 8. For example, a method of inputting a switching control signal of the gate signal cutoff section 24 from the current control section 10 or the relay control section 8 may be adopted, or the gate signal cutoff switching section 24 may be controlled by providing a sub-microcomputer or an ASIC in the arm drive signal switching section 20.

[0164] Fig. 20 is with Fig. 9 The timing diagram of an example of the switching period of the gate drive signal of the arm switch element 4 of the arm drive signal switching unit 20 is shown in conjunction with the relay switching of the relay control unit 8 shown in FIG. Fig. 20 The relay switching operation of the power conversion device 1 is specifically described with reference to the timing chart shown.

[0165] exist Fig. 20At time t30, the fault detection unit 9 detects a fault in the first arm, and the fault detection unit 9 notifies the detected fault content to the outside. In addition, the relay control unit 8 receives the fault content detected and notified by the fault detection unit 9, and implements the switching action of the relay according to the fault content. Since the fault content at time t30 is a fault in the first arm, the relay control unit 8 performs the switching action according to the fault content. Fig. 9 The process of the flowchart shown switches the second to sixth relay control units on and off at time t31.

[0166] The relay control unit 8 switches the first relay 5 from on to off at time t32, and ends the switching operation of the relay. In addition, since the coil winding terminals are in a short-circuit state from time t31 to time t32, and regenerative braking occurs in the rotating electrical machine 3, the corresponding relay is first turned on at time t31, and then the relay switched from on to off is quickly turned off to minimize the occurrence of regenerative braking, thereby minimizing the rotation variation of the rotating electrical machine 3.

[0167] After the relay switching action of the relay control unit 8 is completed, the arm drive signal switching unit 20 switches the gate drive signal of the switching element 4 of each arm through the gate signal cutoff switching unit 24 at time t33 based on the conduction and disconnection states from the first relay 5 to the sixth relay 18 performed by the relay control unit 8.

[0168] Fig. 20 The following example is shown, in which the gate drive signal of the first arm is turned off by the gate signal cut-off switching unit 24, the gate drive signal of the second arm is switched from the gate drive signal of the arm for the V-phase coil of the rotating electric machine 3 to the gate drive signal of the arm for the U-phase coil, the gate drive signal of the third arm is switched from the gate drive signal of the arm for the W-phase coil of the rotating electric machine 3 to the gate drive signal of the arm for the V-phase coil, and the gate drive signal of the fourth arm is switched from the cut-off state to the gate drive signal of the arm for the W-phase coil of the rotating electric machine 3. Then, from time t24, the power conversion device 1 can perform the power conversion operation again. In addition, if the gate signal cut-off 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 change in the gate rising edge time and falling edge time caused by the switching of the gate wiring can be minimized.

[0169] As described above, the power conversion device in embodiment 6 includes an arm whose number is one less than the number of winding terminals of the rotating motor, and the arm is connected to a DC power supply. The external connection point 44 of the arm composed of a switching element is connected to the coil winding terminal of the rotating motor via a relay. Since power is supplied to the above-mentioned coil winding terminals of two different systems via two relays, each arm also has the function of a redundant arm, and is capable of disconnecting an arm that detects an abnormality, switching the relay, and continuing the power conversion action.

[0170] Since the arm is switched so as to be connected only to a specific coil winding terminal and the drive signal of the arm is switched according to the switching state of the relay, it is possible to avoid a switching target error.

[0171] Since the arm portion formed by the switching element 4 also has the function of a redundant arm, and the coil winding terminals of two different systems are powered via the first relay 5 and the first relay 6, the arm portions of each phase including the relay and the redundant arm can be standardized and modularized, and the cost of the additional structure of the redundant arm can be reduced. Since the arm portion also has the function of a redundant arm, the wiring between the arm portion of the module 7 and the coil winding terminals of the rotating electric machine 3 can be simplified without crossing, and the power conversion device 1 can be miniaturized.

[0172] In addition, the wiring distances from each arm to the coil winding terminals of the rotating motor 3 can be configured to be equal. If the wiring impedance is matched, the heat generation and radiation noise of the power conversion device will not change even after a failure of the arm, and the power conversion action can continue without generating current interference between the coil windings.

[0173] When the induced current flows through the coil winding of the rotating electric machine 3, the relay control unit 8 first conducts the relay in the switching action of the relay, thereby avoiding the jump of the induced voltage caused by the disconnection of the current path, and suppressing the influence of the rotation change of the rotating electric machine 3 caused by the relay switching to the minimum. When the failure of the switching element 4 is detected in the process of supplying power to the rotating electric machine 3, the power conversion device 1 stops the drive of the arm before the switching action of the relay, thereby avoiding the erroneous short circuit of the arm caused by the switching of the relay.

[0174] The power conversion device 1 described above may have a structure in which fuses are respectively provided between each arm and the DC power supply 2. Even if a short circuit fault occurs in an arm, the fuse is used to disconnect only the short circuit current path of the arm where the fault occurs, so that after the short circuit current is cut off, the power conversion operation can be continued using the remaining arms.

[0175] Although the present application describes various exemplary embodiments and examples, the various features, forms, and functions described in one or more embodiments are not limited to being applicable to specific embodiments, and may also be applicable to the embodiments individually or in various combinations. Therefore, it can be considered that countless variations that are not illustrated are also included in the technical scope disclosed in the present application specification. For example, it includes the case where at least one structural element is deformed, the case where at least one structural element is added, or the case where at least one structural element is omitted, and it also includes the case where at least one structural element is extracted and combined with the structural elements of other embodiments.

[0176] Description of symbols

[0177] 1 power conversion device, 2 direct current power supply, 3, 33 rotating electrical machine, 4 switching element, 5 first relay, 6 second relay, 7, 70, 71 module, 8 relay control unit, 9 fault detection unit, 10 current control unit, 11 mechanical contact unit, 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 cut-off switching unit, 25 gate cut-off unit, 40 MOS-FET, 41 first wiring, 42 second wiring, 43 third wiring, 44 external connection point, 45 output point, 46 connection terminal, 80 first arm, 81 second arm, 82 third arm, 83 fourth arm, 100, 101 control device.

Claims

1. A power conversion device, characterized in that: include: A multiphase winding of a rotating electrical machine having connection terminals for each phase; N+1 arms, each having a positive-side switching element connected to the positive side of a DC power supply, a negative-side switching element connected to the negative side of the DC power supply, and a first wiring connecting the positive-side switching element and the negative-side switching element in series and provided with an external connection point, and N+1 is obtained by adding 1 to the number of phases N of the winding; 2N relays, when the N+1 arms are numbered in sequence, two of the relays are respectively provided between the external connection points of two adjacent numbered arms; a second wiring connected in series between the external connection points of the two adjacent numbered arms through the two relays; a third wiring connecting an output point of a portion provided between two of the relays connected in series in the second wiring to a connection terminal of each phase; as well as A relay control section turns on and off the 2N relays so that the external connection point of one arm is connected to each of the connection terminals of the phases.

2. The power conversion device according to claim 1, characterized in that: The external connection point of the arm portion can be connected to a specific one or two of the connection terminals of the winding as a power supply target.

3. The power conversion device according to claim 1, characterized in that: comprising a fault detection unit for detecting a fault of the arm, The relay control unit disconnects the relay directly connected to the external connection point of the arm where the fault detection unit detects a fault, and turns on or off the remaining relays so that the external connection points of the normal arm are respectively connected to the connection terminals of the winding.

4. The power conversion device according to claim 1, characterized in that: comprising four of the arms and six of the 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 rotating electrical machine is connected to a first output point on a wiring connecting the first relay and the second relay. The connection terminal of the second winding of the rotating electric machine is connected to a second output point on the wiring connecting the third relay and the fourth relay, The connection terminal of the third winding of the rotating electric machine is connected to a third output point on the wiring that connects the fifth relay and the sixth relay.

5. The power conversion device according to claim 4, characterized in that: The first arm, the second arm, and the first to third relays are modularized. The third arm, the fourth arm, and the fourth to sixth relays are modularized.

6. The power conversion device according to claim 4, characterized in that: The first arm, the fourth arm, the first relay and the sixth relay are modularized. The second arm, the third arm, and the second to fifth relays are modularized.

7. The power conversion device according to claim 4, characterized in that: comprising a fault detection unit for detecting a fault of the arm, When the fault detection unit detects a fault in the third arm while the first relay, the third relay, and the fifth relay are turned on and the first to third arms are connected to the winding of the rotating electrical machine, the relay control unit turns off the fifth relay and turns on the sixth relay.

8. The power conversion device according to claim 4, characterized in that: comprising a fault detection unit for detecting a fault of the arm, When the fault detection unit detects a fault in the second arm while the second relay, the fourth relay, and the sixth relay are turned on and the second to fourth arms are connected to the winding of the rotating electrical machine, the relay control unit turns off the second relay and turns on the first relay.

9. The power conversion device according to claim 4, characterized in that: comprising a fault detection unit for detecting a fault of the arm, When the fault detection unit detects a fault in the second arm while the first relay, the third relay, and the fifth relay are turned on and the first to third arms are connected to the winding of the rotating electrical machine, the relay control unit turns off the third relay and reverses the on and off of the fourth to sixth relays.

10. The power conversion device according to claim 4, characterized in that: comprising a fault detection unit for detecting a fault of the arm, When the fault detection unit detects a fault in the third arm while the second relay, the fourth relay, and the sixth relay are turned on and the second to fourth arms are connected to the winding of the rotating electrical machine, the relay control unit turns off the fourth relay and reverses the on and off of the first to third relays.

11. The power conversion device according to claim 4, characterized in that: comprising a fault detection unit for detecting a fault of the arm, When the fault detection unit detects a fault in the first arm while the first relay, the third relay, and the fifth relay are turned on and the first to third arms are connected to the winding of the rotating electric machine, the relay control unit turns off the first relay and reverses the turning on and off of the second to sixth relays.

12. The power conversion device according to claim 4, characterized in that: comprising a fault detection unit for detecting a fault of the arm, When the fault detection unit detects a fault in the fourth arm while the second relay, the fourth relay, and the sixth relay are turned on and the second to fourth arms are connected to the winding of the rotating electrical machine, the relay control unit turns off the sixth relay and reverses the turning on and off of the first to fifth relays.

13. The power conversion device according to any one of claims 1 to 12, characterized in that: The wiring distances from the external connection point of the arm portion to the connection terminal of the winding are the same.

14. The power conversion device according to any one of claims 1 to 12, characterized in that: A current control unit is included, which controls the current flowing through the winding by driving the positive electrode side switching element and the negative electrode side switching element, When the relay control section connects the external connection points of a plurality of arms to the connection terminals of the same winding, the current control section stops current control.

15. The power conversion device according to any one of claims 3, 7 to 12, characterized in that: The relay control unit first performs off control when reversing on and off of the plurality of relays, and performs on control after an on delay time has elapsed.

16. The power conversion device according to any one of claims 3, 7 to 12, characterized in that: comprising an induced voltage detection unit, the induced voltage detection unit detecting the induced voltage of the winding, When the on and off of the relay are reversed, the relay control unit first performs on control when the induced voltage detection unit detects the induced voltage, and performs off control after an off delay time has elapsed.

17. The power conversion device according to any one of claims 3, 7 to 12, characterized in that: comprising a rotation detection unit that detects the rotation speed of the rotating electrical machine, When the relay control unit reverses the on and off state of the relay, the relay control unit first performs on control according to the rotation speed, and performs off control after an off delay time has elapsed.

18. The power conversion device according to claim 17, characterized in that: When the relay control unit reverses the on and off state of the relay, the relay control unit first performs on control when the rotation speed is equal to or higher than the determination rotation speed, and performs off control after an off delay time has elapsed.

19. The power conversion device according to any one of claims 1 to 12, characterized in that: The relay is a mechanical relay.

20. The power conversion device according to any one of claims 1 to 12, characterized in that: The relay is an electronic relay.

21. The power conversion device according to claim 20, characterized in that: The electronic relay is composed of two metal oxide film semiconductor field effect transistors whose parasitic diodes are in opposite directions.

22. The power conversion device according to claim 21, characterized in that: The metal oxide semiconductor field effect transistor is a wide bandgap semiconductor made of a material using silicon carbide or gallium nitride.

23. The power conversion device according to any one of claims 3, 7 to 12, characterized in that: include: a current detection unit configured to detect a current flowing through the winding; as well as a current control unit that controls a current flowing through the winding by driving the positive-side switching element and the negative-side switching element, When the fault detection unit detects a fault while the current detection unit detects the current, the relay control unit switches the relay on and off after stopping the current control by the current control unit.

24. The power conversion device according to any one of claims 3, 7 to 12, characterized in that: A current control unit is included, which controls the current flowing through the winding by driving the positive electrode side switching element and the negative electrode side switching element, 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.

25. The power conversion device according to any one of claims 3, 7 to 12, characterized in that: include: a current control unit that outputs drive signals for the positive-side switching element and the negative-side switching element and controls a current flowing through the winding; as well as an arm driving signal switching unit, the arm driving signal switching unit being provided between the current control unit and the arm, and switching a connection destination between the current control unit and the arm according to switching of the relay of the relay control unit between on and off, The arm driving signal switching unit detects on and off switching of the relay by the relay control unit, and switches connection destinations of the current control unit and the arm according to a connection destination of the connection terminal of the winding.

26. The power conversion device according to claim 25, characterized in that: The arm drive signal switching unit includes a gate drive circuit that drives the arm according to the drive signal output by the current control unit. The arm drive signal switching unit detects that the relay control unit switches the relay on and off, and switches the connection destinations of the current control unit and the gate drive circuit according to the connection destination of the connection terminal of the winding.

27. The power conversion device according to claim 25, characterized in that: The arm drive signal switching unit includes: a gate drive circuit that drives the arm according to the drive signal output by the current control unit; and a gate signal cutoff switching unit that disconnects or switches the connection target between the gate drive circuit and the arm. The arm drive signal switching unit detects the on and off switching of the relay by the relay control unit, and disconnects or switches the connection target of the gate drive circuit and the arm through the gate signal cutoff switching unit according to the connection target of the connection terminal of the winding.

28. The power conversion device according to any one of claims 1 to 3, characterized in that: comprising three arms and four 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 rotating electrical machine is connected to a first output point on a wiring connecting the first relay and the second relay. The connection terminal of the second winding of the rotating electric machine is connected to a second output point on the wiring that connects the third relay and the fourth relay.

29. The power conversion device according to claim 28, characterized in that: The first arm and the third arm as well as the first relay and the fourth relay are modularized. The second arm, the second relay, and the third relay are modularized.

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