JP5038930B2 - Protection control device for power conversion circuit - Google Patents

Description

  The present invention relates to a protection control device for a power conversion circuit, and more particularly to protection control of a device against occurrence of overvoltage.

  In a power conversion circuit configured to include a power semiconductor switching element (hereinafter also simply referred to as “switching element”), when an overvoltage occurs in the power conversion circuit, each switching element is forcibly turned off. Therefore, it is common to perform protection control so that equipment destruction does not occur due to the overvoltage being transmitted to the inside or outside of the power conversion circuit.

  In such protection control, in Japanese Patent Application Laid-Open No. 2007-236013 (Patent Document 1), in an electric motor drive device mounted on a hybrid vehicle, an overvoltage signal OVL generated based on a voltage measurement value when an overvoltage is generated, A configuration is shown in which an inverter cutoff signal DWN is generated based on a logical product with a cutoff permission signal RG from an electronic control unit (ECU).

  With such a configuration, the switching permission signal RG is normally set to a logic high level (hereinafter also simply referred to as H level) by the ECU so that each switching element of the inverter is immediately responded to the overvoltage signal OVL when an overvoltage occurs. Can be forcibly turned off so that the gate is cut off. Furthermore, once it is determined that conditions for enabling retreat travel by the hybrid vehicle are established after ensuring safety in the gate cutoff state, a cutoff permission signal RG is generated by arithmetic processing in an ECU (CPU: Central Processing Unit). By changing to a logic low level (hereinafter also simply referred to as L level), the inverter can be operated again, and the retreat travel can be performed by the output of the motor generator.

Japanese Patent Laying-Open No. 2005-261127 (Patent Document 2) receives an electric machine, a drive signal generation processing unit that receives a command value and generates a drive signal, and a drive signal as an abnormality determination device for an electric vehicle. And an inverter that generates current and supplies the electric machine to the electric machine, and a drive line that connects between the drive signal generation processing unit and the inverter, and is determined to be branched from the drive line and connected to the power source. It is described that it is determined whether or not an abnormality has occurred in the driving line based on the signal of the driving line. In this case, it is not necessary to send the drive signal from the drive signal generation processing unit to the inverter, so that it is determined whether an abnormality has occurred in the drive line without driving the electric machine and outputting the rotation. be able to.
JP 2007-236013 A JP 2005-261127 A

  When an abnormality such as disconnection occurs in a line that connects a device such as a drive line of Patent Literature 2 and a control device, in the configuration of Patent Literature 1, a gate cutoff command signal (DWN) is input to the inverter. Since it becomes impossible, it will be in a state with a problem on apparatus protection.

  That is, in the configuration of the electric motor drive device described in Patent Document 1, since a single cutoff permission signal DWN is input to the inverter, the inverter is turned on again in response to the output from the ECU after the gate is cut off. Flexible protection control that enables evacuation travel is realized by operating, but if a disconnection occurs in the transmission line of the cutoff permission signal DWN, the gate cutoff command cannot be input to the inverter, which causes a problem in equipment protection. May occur.

  The present invention has been made in order to solve such problems, and an object of the present invention is to detect when an overvoltage occurs in protection control of a power conversion circuit by a combination of hardware overvoltage detection and CPU arithmetic processing. Is to fully protect the equipment.

  A protection control device for a power conversion circuit according to the present invention is a protection control device for a power conversion circuit including a power semiconductor switching element connected to a power supply wiring, and includes an overvoltage detection circuit, an arithmetic device, a logic device, A circuit, a first signal line, and a second signal line are provided. The overvoltage detection circuit generates an overvoltage signal when an overvoltage of the power supply wiring is detected. The arithmetic device generates a compulsory cutoff command signal for the power semiconductor switching element by a predetermined arithmetic processing based on the overvoltage signal from the overvoltage detection circuit. The logic circuit generates a compulsory shut-off command signal for the power semiconductor switching element when an overvoltage signal is generated based on the output signal from the arithmetic unit and the output signal from the overvoltage detection circuit. The first signal line transmits the cutoff command signal generated by the arithmetic device to the power conversion circuit. The second signal line is provided separately from the first signal line, and transmits the cutoff command signal generated by the logic circuit to the power conversion circuit.

  According to the protection control device for the power conversion circuit, a cutoff command signal generated by a combination of hardware overvoltage detection and CPU arithmetic processing is generated in each of the arithmetic device and the logic circuit, and by a separate signal line. A duplex system can be configured to transmit to the power conversion circuit. As a result, even if an abnormality such as disconnection occurs in one of the signal lines, the interruption command signal can be reliably transmitted to the power conversion circuit, so that it is possible to sufficiently protect the device when an overvoltage occurs.

  Preferably, the power conversion circuit is connected between the two power supply wirings and configured to perform power conversion between the two power supply wirings, and the logic circuit includes first to third logical operation units. . The first logic operation unit receives an output signal from the arithmetic unit and an overvoltage signal generated when the overvoltage detection circuit detects an overvoltage of the first power supply wiring of the two power supply wirings. Composed. The second logical operation unit is configured to receive an output signal from the arithmetic unit and an overvoltage signal generated when the overvoltage detection circuit detects an overvoltage of the second power supply line of the two power supply lines. The The third logic unit is configured to receive the output signals of the first and second logic units as inputs and to output a cutoff command signal.

  More preferably, the power conversion circuit is mounted on an electric vehicle configured to generate at least part of the vehicle driving force by an AC rotating electric machine. The power conversion circuit includes a converter that performs DC voltage conversion between the power storage device connected to the first power supply wiring and the inverter connected to the second power supply wiring. It is driven by the supply of AC power converted by.

  Preferably, even if an overvoltage signal is generated, the arithmetic unit makes a shut-off command signal from the arithmetic unit non-generated and is shut off in the logic circuit when it is determined that the overvoltage detection circuit is erroneously detected. The output signal is set so that the command signal is not generated.

  Preferably, the output signal from the arithmetic unit to the logic circuit is set so that the logic circuit generates a shut-off command signal in response to the occurrence of the overvoltage signal before the overvoltage signal is generated. After the occurrence of, the logic circuit is set so as not to generate the shut-off command signal regardless of the overvoltage signal when it is determined that the detection error is caused by the overvoltage detection circuit.

  In this way, when an overvoltage signal is generated, the power conversion circuit (converter) is quickly gated to ensure safety, while if it can be determined that the overvoltage signal has been generated by a false detection, The operation of the power conversion circuit can be resumed with the interruption command signal not generated by the CPU arithmetic processing. Thereby, in the electric vehicle, the retreat travel using the vehicle driving force by the AC rotating electric machine is possible.

  According to the protection control device for a power conversion circuit of the present invention, in the protection control of the power conversion circuit by a combination of hardware overvoltage detection and CPU arithmetic processing, it is possible to sufficiently protect the device when an overvoltage occurs.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

  FIG. 1 is a schematic block diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with a protection control device for a power conversion circuit according to an embodiment of the present invention.

  Referring to FIG. 1, hybrid vehicle 100 includes wheels 2, a power split mechanism 3, an engine 4, motor generators MG1 and MG2, and an electronic control unit (hereinafter also referred to as “ECU”). 60.

  The ECU 60 includes a CPU 61, a ROM (Read Only Memory) 62, and a RAM (Random Access Memory). The CPU 61 performs arithmetic processing based on signals and information transmitted from each sensor, a map and a program stored in the ROM 62, and controls devices so that the hybrid vehicle 100 is in a desired driving state. Alternatively, at least a part of the ECU 60 may be configured to execute predetermined numerical / logical operation processing by hardware such as an electronic circuit. As will be apparent from the following description, a protection control device for a power conversion circuit according to the present invention is realized as a partial function of the ECU 60.

  Hybrid vehicle 100 includes power storage device B, system main relay (hereinafter also referred to as “SMR”) 5, converter 10, inverters 20 and 30, capacitors C1 and C2, and power supply line PL1. , PL2, a ground line SL, voltage sensors 75 and 77, and current sensors 76 and 78.

  Power split device 3 is coupled to engine 4 and motor generators MG1 and MG2 to distribute power between them. For example, as power split mechanism 3, a planetary gear mechanism having three rotation shafts of a sun gear, a planetary carrier, and a ring gear can be used. These three rotating shafts are connected to the rotating shafts of engine 4 and motor generators MG1, MG2, respectively. For example, engine 4 and motor generators MG1 and MG2 can be mechanically connected to power split mechanism 3 by making the rotor of motor generator MG1 hollow and passing the crankshaft of engine 4 through its center.

  The rotating shaft of motor generator MG2 is coupled to wheel 2 by a reduction gear and an operating gear (not shown). Further, a reduction gear for the rotation shaft of motor generator MG2 may be further incorporated in power split device 3.

  Motor generator MG1 operates as a generator driven by engine 4 and is incorporated into hybrid vehicle 100 as an electric motor that can start engine 4, and motor generator MG2 is a drive wheel. It is incorporated in hybrid vehicle 100 as an electric motor that drives wheels 2.

  The power storage device B is a chargeable / dischargeable DC power source, and is composed of, for example, a secondary battery such as nickel metal hydride or lithium ion. Power storage device B supplies DC power to power supply line PL1 via SMR5. Power storage device B is charged by receiving DC power output from converter 10 to power supply line PL1. Note that a large-capacity capacitor may be used as the power storage device B.

  SMR 5 includes relays RY1 and RY2. Relay RY1 is connected between the positive electrode of power storage device B and power supply line PL1. Relay RY2 is connected between the negative electrode of power storage device B and ground line SL. Relays RY1 and RY2 connect power storage device B to power supply line PL1 and ground line SL when signal SE from ECU 60 is activated.

  Capacitor C1 smoothes voltage fluctuation between power supply line PL1 and ground line SL. Voltage sensor 75 detects voltage VL across capacitor C1, and outputs the detected voltage VL to ECU 60.

  Connected between power supply line PL1 and ground line SL is DCDC converter 6 for converting the voltage of power supply line PL1 into a power supply voltage for driving auxiliary device 8.

  Converter 10 includes power semiconductor switching elements (switching elements) Q1, Q2, diodes D1, D2, and a reactor L. Switching elements Q1, Q2 are connected in series between power supply line PL2 and ground line SL. Diodes D1 and D2 are connected in antiparallel to switching elements Q1 and Q2, respectively. Reactor L is connected between power supply line PL1 and the connection point of switching elements Q1, Q2.

  Converter 10 boosts the voltage of power supply line PL1 based on signal PWC from ECU 60 and outputs the boosted voltage to power supply line PL2. Specifically, converter 10 stores a current flowing when switching element Q2 is turned on as magnetic field energy in reactor L, and discharges the stored energy to power supply line PL2 via diode D1 when switching element Q2 is turned off. The voltage of line PL1 is boosted.

  Note that increasing the on-duty of the switching element Q2 increases the power storage in the reactor L, so that a higher voltage output can be obtained. On the other hand, increasing the on-duty of the switching element Q1 reduces the voltage of the power supply line PL2. Therefore, by controlling the duty ratio of switching elements Q1, Q2, the voltage of power supply line PL2 can be controlled to an arbitrary voltage equal to or higher than the voltage of power supply line PL1.

  In the embodiment of the present invention, an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor) transistor, a power bipolar transistor, or the like can be used as the power semiconductor switching element (switching element). Anti-parallel diodes D1, D2 are arranged for switching elements Q1, Q2. In addition, converter 10 constitutes a “power conversion circuit” that is subject to protection control in the present embodiment.

  Capacitor C2 smoothes voltage fluctuation between power supply line PL2 and ground line SL. Voltage sensor 77 detects voltage VH across capacitor C2, and outputs the detected voltage VH to ECU 60.

  Inverters 20 and 30 are provided corresponding to motor generators MG1 and MG2, respectively. Inverter 20 drives motor generator MG1 in the power running mode or the regeneration mode based on signal PWM1 from ECU 60. Similarly, inverter 30 drives motor generator MG2 in the power running mode or the regenerative mode based on signal PWM2 from ECU 60.

  Current sensor 76 detects motor current MCRT1 flowing through motor generator MG1, and outputs the detected motor current MCRT1 to ECU 60. Current sensor 78 detects motor current MCRT2 flowing through motor generator MG2, and outputs the detected motor current MCRT2 to ECU 60.

  ECU 60 receives voltages VL and VH from voltage sensors 75 and 77, respectively, and receives motor currents MCRT1 and MCRT2 from current sensors 76 and 78, respectively. ECU 60 also receives torque command values TR1, TR2 and motor rotational speeds MRN1, MRN2 from an external ECU (not shown).

  Based on these signals, ECU 60 generates signals PWC, PWM1, and PWM2 for driving converter 10 and motor generators MG1 and MG2, respectively, and generates the generated signals PWC, PWM1, and PWM2 respectively. Output to inverters 20 and 30. ECU 60 generates signal SE to turn on SMR 5 when the vehicle system is activated, and does not generate signal SE when the vehicle system is shut off.

  As understood from FIG. 1, when an overvoltage occurs in the power supply line PL2 (VH), the overvoltage of the power supply line PL2 is transmitted to the power supply line PL1 unless the switching element Q1 is securely turned off. A device failure may occur in the converter 6 or the like. Further, even when an overvoltage occurs in the power supply line PL1 (VL), it is necessary to reliably turn off the switching element Q2 in order to prevent the occurrence of an overcurrent. Further, in order to prevent the overvoltage from being transmitted to the power supply line PL1, it is necessary to turn off the switching element Q1.

  Thus, when an overvoltage occurs in power supply line PL1 (VL) and / or power supply line PL2 (VH), a forcible shut-off command is given to converter 10 to promptly force each switching element Q1, Q2. It is necessary to make the gate cut-off state that turns off automatically.

  When an overvoltage occurs, the inverters 20 and 30 are also turned off. During the gate cut-off state, the power lines PL2 and PL1 are lowered due to power consumption by a discharge resistor (not shown) connected in parallel with the capacitor C2 and power consumption by the auxiliary machine 8.

  Then, after the voltage of the power supply line in which the overvoltage has occurred is reduced, if it is confirmed that the vehicle can be evacuated, only the switching element Q1 is always turned on in the converter 10, thereby By converting the voltage to an AC voltage by inverter 20 and / or 30, motor generator MG1 and / or MG2 can be driven and controlled to generate vehicle driving force for evacuation travel.

  For this reason, from the viewpoint of equipment protection, while promptly issuing a gate cutoff command in response to the occurrence of an overvoltage, it was once set when it was found that the overvoltage was erroneously detected due to a failure in the overvoltage detection circuit, etc. It is preferable to adopt a flexible control configuration that can release the gate cutoff state.

  FIG. 2 is a functional block diagram of ECU 60 shown in FIG. Referring to FIG. 2, ECU 60 includes a converter control unit 71, first and second inverter control units 72 and 73, and a gate cutoff control unit 74.

  Converter control unit 71 calculates a voltage command for power supply line PL2 based on torque command values TR1, TR2 and motor rotational speeds MRN1, MRN2, and calculates a feedback voltage command based on voltages VL, VH. Then, converter control unit 71 calculates the duty ratio of switching elements Q1, Q2 based on the feedback voltage command, and generates a PWM (Pulse Width Modulation) signal for turning on / off switching elements Q1, Q2. Output to the converter 10 as PWC.

  First inverter control unit 72 generates a PWM signal for driving inverter 20 based on torque command value TR1, voltage VH, and motor current MCRT1, and outputs the generated PWM signal to inverter 20 as signal PWM1. To do. Similarly, second inverter control unit 73 generates a PWM signal for driving inverter 30 based on torque command value TR2, voltage VH, and motor current MCRT2, and uses the generated PWM signal as signal PWM2 to generate an inverter. Output to 30.

  The gate shut-off control unit 74 generates an overvoltage signal OVL generated when an overvoltage occurs in the power supply line PL1, an overvoltage signal OVH generated when an overvoltage occurs in the power supply line PL2, and detection voltages VL and VH detected by the voltage sensors 75 and 77. Based on the above, the signals SDWN, OVL-RG, and OVL-HG related to protection control are generated in order to place the converter 10 in the gate cutoff state when an overvoltage occurs in the power supply lines PL1 and PL2.

  In the hybrid vehicle 100 as a whole, protection control for shutting down the gate of the converter 10 is executed even when an abnormality other than the occurrence of the overvoltage occurs. In the present embodiment, protection control related to overvoltage generation will be described.

  Next, with reference to FIG. 3 to FIG. 5, a description will be given of a control configuration relating to overvoltage detection and generation and transmission of a gate cutoff command in response to the overvoltage detection by the power conversion circuit protection device according to the embodiment of the present invention.

  FIG. 3 is a block diagram illustrating a maintenance control configuration of a power conversion circuit shown as a comparative example of the embodiment of the present invention.

  Referring to FIG. 3, the IPM (Intelligent Power Module) includes switching elements constituting converter 10 and inverters 20 and 30, and gate drive for controlling on / off of these switching elements according to a control signal from ECU 60. A circuit is installed. In particular, on / off of switching elements Q 1 and Q 2 constituting converter 10 is controlled by converter gate drive circuit 11.

  The OVL detection circuit 90 is configured by hardware on the IPM, and sets the overvoltage signal OVL to H level when the voltage VL detected by the voltage sensor 75 exceeds a predetermined upper limit voltage. Similarly, OVH detection circuit 95 sets overvoltage signal OVL to the H level when voltage VH detected by voltage sensor 77 exceeds a predetermined upper limit voltage. In the following, setting each signal to H level is also expressed as “generating that signal”, and setting it to L level is also expressed as “not generating the signal”.

  The OVL detection circuit 90 and the OVH detection circuit 95 can be configured by, for example, a differential amplifier circuit that amplifies and outputs a voltage difference between the output voltage from the voltage sensors 75 and 77 and a predetermined upper limit voltage.

  By using an overvoltage detection circuit (generically referring to the OVL detection circuit 90 and the OVH detection circuit 95, hereinafter the same) configured by hardware, the CPU 61 performs arithmetic processing based on the digital conversion value of the detection voltage by the voltage sensors 75 and 77. Therefore, the overvoltage signals OVL and OVH can be generated at a higher speed than the configuration that generates the overvoltage signals OVL and OVH.

  Overvoltage signals OVL and OVH are input to CPU 61 in ECU 60. The CPU 61 corresponds to the “arithmetic apparatus” in the present invention, and controls generation / non-generation of the shut-off command signal SDWN by executing arithmetic processing (CPU processing) according to the flowchart shown in FIG. 4 at predetermined intervals.

  Referring to FIG. 4, CPU 61 determines in step S100 whether at least one of overvoltage signal OVH and OVL signal is generated by the overvoltage detection circuit. When an overvoltage signal is generated (YES in S100), the CPU 61 advances the process to step S110 to determine whether the generation of the overvoltage signals OVL and OVH is a false detection due to a failure of the overvoltage detection circuit or the like. Determine whether. For example, based on the comparison between the detected voltages of the voltage sensors 75 and 77 and the overvoltage signals OVL and OVH, specifically, the overvoltage signal is generated while the detected voltage is in the normal range over a certain period. In such a case, it can be determined that an erroneous detection of the overvoltage signal has occurred.

  When CPU 61 determines that the overvoltage signal is normal (NO in S110), CPU 61 advances the process to step S120, and sets cutoff command signal SDWN to the H level. That is, a cutoff command signal SDWN is generated.

  On the other hand, the CPU 61 assumes that neither the overvoltage signal OVH nor the OVL signal is generated (when NO is determined in S100) or at least one of the overvoltage signal OVH or OVL signal is generated due to a false detection. When it is determined (YES in S110), the process proceeds to step S130, and the cutoff command signal SDWN is set to L level. That is, the cutoff command signal SDWN is not generated.

  Referring to FIG. 3 again, the CPU 61 sets the signal OVL-RG to the H level at the normal time, while the overvoltage signal OVL is generated and it is determined that the generation is due to a false detection. Set to L level. Similarly, CPU 61 sets signal OVH-RG to the H level in the normal state, while overvoltage signal OVH is generated after converter 10 is once turned off by generation of overvoltage signal OVH, and When it is determined that the occurrence is due to erroneous detection, the L level is set.

  The logic circuit 101 generates a final gate cutoff command signal CSDN in response to the output signals OVL-RG, OVH-RG from the CPU 61 and the overvoltage signals OVL, OVH generated by the IPM.

  The logic circuit 101 outputs a logical product operation result of the signal OVH-RG and the overvoltage signal OVH from the CPU 61, and a logical gate output of a logical product operation result of the signal OVL-RG and the overvoltage signal OVL from the CPU 61. 104, and a logic gate 106 that outputs a logical sum operation result of the output signals of the logic gates 102 and 104 and the cutoff command signal SDWN from the CPU 61 as the gate cutoff command signal CSDN.

  The gate cutoff command signal CSDN output from the logic gate 106 is transmitted from the ECU 60 to the converter gate drive circuit 11 on the IPM via the signal line 110. Further, the CPU 61 generates a signal PWC (FIG. 1) for controlling the converter 10 at a normal time by the functional part of the converter control unit 71 in FIG. 2, and transmits the signal PWC to the converter gate drive circuit 11 through the signal line 115.

  Converter gate drive circuit 11 controls on / off of switching elements Q1 and Q2 in response to a signal PWC transmitted through signal line 115 during normal operation. On the other hand, when receiving the gate cutoff command signal CSDN via the signal line 110, the converter gate drive circuit 11 forcibly turns off the switching elements Q1 and Q2 to enter the gate cutoff state.

  According to the configuration of FIG. 3, when an overvoltage occurs, the gate is cut off by the output of the logic gates 102 and / or 104 based on the overvoltage signals OVL and / or OVH generated at high speed by the overvoltage detection circuit configured by hardware. Command signal CSDN can be generated. Once the gate is cut off, when the voltages VH and VL are reduced due to power consumption and the overvoltage state is eliminated, the gate is turned on in response to the overvoltage signals OVL and / or OVH not being generated. The gate cutoff state can be canceled by not generating the cutoff command signal CSDN.

  Further, when the overvoltage signals OVL and OVH are generated due to erroneous detection due to a failure of the overvoltage detection circuit or the like, if the detection values by the voltage sensors 75 and 77 are within the normal range, the signal SDWN, The gate cutoff state can be canceled by OVL-RG and OVL-HG.

  Note that after the gate cutoff state is released, a path for supplying power from power storage device B (FIG. 1) to inverters 20 and 30 by operating converter 10 and turning on switching element Q1 of converter 10 Can be formed. Thereby, for example, when it is determined that a device group for driving by driving motor generator MG2 using electric power from power storage device B is usable based on the failure status information, or instructing retreat driving When the switch or the like is operated by the driver, the retreat traveling with the operation of the converter 10 can be executed.

  However, in the configuration shown in FIG. 3, since the transmission path of the gate cutoff command signal from the ECU 60 to the IPM is a single system, even if an overvoltage occurs when the signal line 110 is disconnected, the converter 10 is shut off. It becomes impossible to be in a state.

  When such a state occurs, as understood from FIG. 1, for example, when switching element Q1 and / or Q2 is turned on, an overvoltage generated in power supply line PL1 or PL2 causes DCDC converter 6, capacitor C1, There is a possibility that equipment damage due to overvoltage occurs in components inside and / or outside of the power conversion circuit such as C2.

  FIG. 5 is a block diagram showing a control configuration by the protection control device of the power conversion circuit according to the embodiment of the present invention, which has been proposed to solve this point.

  Referring to FIG. 5, according to the control configuration according to the embodiment of the present invention, ECU 60 has a logic circuit 101 # in place of logic circuit 101 shown in FIG. Logic circuit 101 # has logic gate 108 in place of logic gate 106 in addition to logic gates 102 and 104 similar to those in FIG. Logic gate 108 outputs a logical sum operation result of the output signals from logic gates 102 and 104. Since the structure of the other part of FIG. 5 is the same as that of FIG. 3, the description is not repeated.

  The ECU 60 outputs the cutoff command signal SDWN from the CPU 61 and the cutoff command signal generated by the logic gate 108 as separate gate cutoff command signals CSDN1 and CSDN2. Gate cutoff command signals CSDN1 and CSDN2 are transmitted to converter gate drive circuit 11 on the IPM via separate signal lines 110 and 111.

  That is, the generation of the gate cutoff command signal and the transmission from the ECU 60 to the IPM (converter gate drive circuit 11) form a dual system by the signal lines 110 and 111. Converter gate drive circuit 11 forcibly turns off switching elements Q1 and Q2 to place converter 10 in a gate cutoff state when at least one of gate cutoff command signals CSDN1 and CSDN2 is generated.

  As described above, the cutoff command signal SDWN from the CPU 61 is generated according to the flowchart shown in FIG. 4 based on the overvoltage signals OVH and OVL, and is thus generated by a combination of hardware overvoltage detection and CPU arithmetic processing. ing. Similarly, logic circuit 101 # is also generated based on overvoltage signals OVH and OVL and signals OVL-RG and OVH-RG from CPU 61, and is therefore generated by a combination of hardware overvoltage detection and CPU arithmetic processing. ing.

  As described above, according to the protection control device for a power conversion circuit according to the present embodiment, even if a disconnection occurs in one of the signal lines 110 and 111, a gate cutoff command can be reliably transmitted from the ECU 60 to the converter 10. By reliably setting the converter 10 to the gate cutoff state by the ECU 60, it is possible to improve the device protection performance when an overvoltage occurs.

  Further, when the overvoltage can be determined to be erroneously detected by the signals SDWN, OVH-RG, and OVL-RG generated by the CPU 61, each of the gate cutoff command signals CSDN1 and CSDN1 and 2 can be made non-generated (L level). This is the same as FIG. That is, if a gate cutoff command is generated by a combination of hardware overvoltage detection and CPU calculation processing, and it turns out that it is a false detection of an overvoltage due to a failure in the overvoltage detection circuit, etc., the gate cutoff state once set A flexible control configuration that can be released is maintained.

  In the present embodiment, only the protection control against overvoltage generation has been described. However, as described above, actually, any one of a plurality of predetermined abnormal states including overvoltage generation is detected. The point that the gate cutoff command is generated in the event of failure will be described in a confirming manner. Further, the gate cutoff command to the inverters 20 and 30 will also be described in terms of confirmation that it can be configured similarly to the converter 10.

  In the above-described embodiment, the hybrid vehicle having the parallel hybrid configuration in which both the engine and the motor generator (MG2) can generate the wheel driving force is illustrated. However, the engine operates only as a power supply source to the motor and is directly connected. The present invention can also be applied to protection control from overvoltage of a power conversion circuit even in a hybrid vehicle having a series hybrid configuration in which wheel driving is performed by a motor.

  Similarly, in the above-described embodiment, the engine 4 and the motor generators MG1, MG2 are connected via the planetary gear mechanism, and the mechanical distribution type hybrid vehicle that performs energy distribution by the planetary gear mechanism is exemplified. The present invention can also be applied to an electric distribution type hybrid vehicle. In addition, the present invention can be applied to the protection of equipment in the power conversion circuit for controlling the electric motor for all electric vehicles including the electric motor for generating the wheel driving force including the electric vehicle not equipped with the engine. Is described in a confirming manner.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a schematic block diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with a protection control device for a power conversion circuit according to an embodiment of the present invention. It is a functional block diagram of ECU shown in FIG. It is a block diagram which shows the protection control structure of the power converter circuit shown as a comparative example of embodiment of this invention. It is a flowchart explaining the arithmetic processing by CPU. It is a block diagram which shows the control structure by the protection control apparatus of the power converter circuit by embodiment of this invention.

Explanation of symbols

  4 engine, 6 DCDC converter (for auxiliary machine), 8 auxiliary machine, 10 converter (power conversion circuit), 11 converter gate drive circuit, 20, 30 inverter, 71 converter control unit, 72, 73 inverter control unit, 74 gate shut off Control unit (overvoltage), 75, 77 voltage sensor, 76, 78 current sensor, 90 OVL detection circuit (overvoltage detection circuit), 95 OVH detection circuit (overvoltage detection circuit), 100 hybrid vehicle, 101, 101 # logic circuit, 102 , 104, 106, 108 logic gate, 110, 111 signal line (gate cutoff command signal), 115 signal line (switching control signal), B power storage device, C1, C2 capacitor, CSDN, CSDN1, CSDN2 gate cutoff command signal, D1 , D2 diode, L reactor, MCRT1, MCRT2 Motor current, MG1, MG2 Motor generator, MRN1, MRN2 Motor speed, OVH, OVL Overvoltage signal, OVL-RG, OVH-RG Output signal (CPU), PL1, PL2 Power line, PWC, PWM1, PWM2 signal (Switching control), Q1, Q2 power semiconductor switching element, RY1, RY2 relay, SDWN cutoff command signal (CPU), SL ground line, TR1, TR2 torque command value, VL sensor detection voltage (power supply line PL1), VH sensor Detection voltage (power supply line PL2).

Claims (5)

A protection control device for a power conversion circuit configured to include a power semiconductor switching element connected to a power supply wiring,
An overvoltage detection circuit for generating an overvoltage signal at the time of overvoltage detection of the power supply wiring;
An arithmetic device that generates a forced cutoff command signal for the power semiconductor switching element by a predetermined arithmetic processing based on the overvoltage signal from the overvoltage detection circuit;
Logic for generating a compulsory shut-off command signal for the power semiconductor switching element when the overvoltage signal is generated based on the output signal from the arithmetic unit and the output signal from the overvoltage detection circuit Circuit,
A first signal line for transmitting the cutoff command signal generated by the arithmetic unit to the power conversion circuit;
Protection control of a power conversion circuit, comprising: a second signal line provided separately from the first signal line for transmitting the cutoff command signal generated by the logic circuit to the power conversion circuit apparatus. The power conversion circuit is connected between the two power supply lines, and is configured to perform power conversion between the two power supply lines.
The logic circuit is:
A first logical operation unit that receives an output signal from the arithmetic unit and an overvoltage signal generated when the overvoltage detection circuit detects an overvoltage of a first power supply line of the two power supply lines;
A second logic operation unit that receives an output signal from the arithmetic unit and an overvoltage signal generated when the overvoltage detection circuit detects an overvoltage of a second power supply line of the two power supply lines; 2. A protection control device for a power conversion circuit according to claim 1, further comprising: a third logic operator that receives the output signals of 1 and the second logic operator and outputs the shut-off command signal. The power conversion circuit is mounted on an electric vehicle configured to generate at least a part of a vehicle driving force by an AC rotating electric machine,
The power conversion circuit is configured by a converter that performs DC voltage conversion between the power storage device connected to the first power supply wiring and the inverter connected to the second power supply wiring,
The protection control device for a power conversion circuit according to claim 2, wherein the AC rotating electric machine is driven by being supplied with AC power converted by the inverter.   When the overvoltage signal is generated, the arithmetic device makes the shut-off command signal from the arithmetic device non-generated and determines that the logic The protection control device for a power conversion circuit according to any one of claims 1 to 3, wherein the output signal is set so that the cutoff command signal is not generated in the circuit.   The output signal from the arithmetic unit to the logic circuit is set so that the logic circuit generates the cutoff command signal in response to the generation of the overvoltage signal before the generation of the overvoltage signal. After the occurrence of the overvoltage signal, the logic circuit is set so that the shut-off command signal is not generated regardless of the overvoltage signal when it is determined that the detection error is caused by the overvoltage detection circuit. The protection control device for a power conversion circuit according to any one of claims 1 to 3.

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