JP2015162977A - electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress incorrectly detecting insulation degradation caused by retention of coolant in a compressor as insulation degradation at a part on a battery side instead of an air conditioning inverter.SOLUTION: When insulation degradation on an HV battery side of a step-up circuit is detected (step S100), if voltage difference of a battery voltage system power line which is a power line on the HV battery side of the step-up circuit is a determination threshold value V1 or higher, SMR check is performed (step S130, S140). Thus, it is suppressed that degradation in insulation resistance caused by retention of a coolant in an air conditioning device is incorrectly detected as insulation degradation on the HV battery side of the step-up circuit.

Description

  The present invention relates to an electric vehicle, and more specifically, a motor, a battery, a booster circuit that boosts power supplied from the battery and supplies the motor, an air conditioner having a compressor that compresses refrigerant, a battery, and a booster circuit The present invention relates to an electric vehicle including a system main relay connected between and an air conditioning inverter connected to a power line connecting the system main relay and a booster circuit to drive a compressor.

  Conventionally, as this type of electric vehicle, a motor, a high-voltage battery, an inverter for driving the motor, a converter that performs voltage conversion between the high-voltage battery and the inverter, and a high-voltage battery and the converter are connected. A high voltage system having two relays respectively provided on the two power lines is mounted, and the presence or absence of a decrease in impedance between the high voltage system and the vehicle body is detected, and it is determined that the insulation resistance decrease is abnormal The thing is proposed (for example, refer patent document 1). In this vehicle, when it is determined that there is a decrease in insulation resistance, the state in which the gate of the inverter is fixed to ON while the voltage is applied to the inverter is changed to a state in which all gates are cut off (the gate is fixed to OFF). If there is no change from the decrease in insulation resistance before and after switching and switching of the gate state, the part on the high voltage battery side (DC part) from the inverter is identified as the reduced insulation part and insulated before and after switching the gate state. When the decrease in resistance changes from being lowered to not being lowered, the part on the motor side (AC part) from the inverter is specified as the insulation lowered part.

JP 2013-172542 A

  By the way, in addition to the configuration of the electric vehicle described above, an air conditioner having a compressor for compressing a refrigerant for air conditioning, an air conditioning inverter connected to two power lines connecting the converter and the high voltage battery, and driving the compressor, In the electric vehicle further including the above, there is a case where a decrease in insulation resistance due to the refrigerant remaining in the air conditioner is erroneously detected as a decrease in insulation on the battery side of the air conditioning inverter. When the air conditioning inverter gate is turned off (gate shut-off), such as during the Ready-OFF sequence, the compressor stops and refrigerant accumulates in the air conditioner, the capacity (common capacity) between the compressor and the vehicle body increases. As a result, impedance decreases. At this time, the diode included in the air conditioning inverter may be conductive depending on the bias condition. However, if a decrease in insulation resistance is detected in a state where such a diode is conductive, the insulation resistance of the compressor is decreased. A reduction in insulation resistance on the battery side of the inverter for air conditioning is erroneously detected.

  The electric vehicle of the present invention is mainly intended to suppress erroneous detection of a decrease in insulation caused by the retention of refrigerant in an air conditioner as a decrease in insulation resistance at a battery-side portion from the inverter for air conditioning.

  The electric vehicle of the present invention employs the following means in order to achieve the main object described above.

The electric vehicle of the present invention is
A motor, a battery, a booster circuit that boosts electric power supplied from the battery and supplies the booster to the motor, an air conditioner having a compressor that compresses refrigerant, and the battery and the booster circuit are connected A voltage system including a system main relay, an air conditioning inverter connected to a power line connecting the system main relay and the booster circuit, and driving the compressor; and an electric signal connected to a positive electrode or a negative electrode of the battery An insulation decrease detection device that performs insulation decrease detection for detecting a decrease in insulation resistance by application, and an electric vehicle comprising:
When the insulation drop of the voltage system is detected, the insulation drop detection device performs the insulation drop detection by turning off the gate of the air conditioning inverter in a state where the voltage of the power line is equal to or higher than a predetermined voltage. The gist is that it is a device to be used.

  In the electric vehicle according to the present invention, when the insulation drop of the voltage system is detected, the insulation line is detected by turning off the gate of the air conditioning inverter in a state where the voltage of the power line is equal to or higher than the predetermined voltage. Insulation drop detection is performed in a state where each diode included in the air conditioning inverter is not conductive. Therefore, detection of a decrease in insulation resistance is performed not on the compressor side of the air conditioning inverter but on the battery side of the air conditioning inverter. Can do. Thereby, it can suppress that the fall of the insulation resistance by the refrigerant | coolant stagnating in an air conditioner is erroneously detected as the fall of the insulation resistance of the site | part of a battery side from the inverter for an air conditioning.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 1 is a configuration diagram illustrating an outline of a configuration of a voltage system included in a hybrid vehicle 20. It is explanatory drawing which shows the insulation resistance fall detector 90 and the simple model 99 of the system to which this insulation resistance fall detector 90 was connected. 5 is a flowchart illustrating an example of an insulation decrease detection processing routine executed by an HVECU 70. It is a flowchart which shows an example of the insulation fall detection processing routine of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of a configuration of a voltage system included in the hybrid vehicle 20. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 that uses gasoline or light oil as fuel, an engine electronic control unit (hereinafter referred to as engine ECU) 24 that controls the drive of the engine 22, and a crank of the engine 22. A planetary gear 30 having a carrier connected to the shaft 26 and a ring gear connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37, and a rotor configured as a synchronous generator motor, for example. A motor MG1 connected to the sun gear, a motor MG2 configured as a synchronous generator motor and having a rotor connected to the drive shaft 36, inverters 41 and 42 for driving the motors MG1 and MG2, an inverter 41, 42 is controlled by switching control. A motor electronic control unit (hereinafter referred to as a motor ECU) 40 for driving and controlling the MG1 and MG2, an HV battery 50 configured as, for example, a lithium ion secondary battery, and a battery electronic control unit for managing the HV battery 50 ( Hereinafter, the battery ECU 52, a power line (hereinafter referred to as a high voltage system power line) 54a connected to the inverters 41 and 42, and a power line (hereinafter referred to as the HV battery 50) via the system main relay SMR. The voltage VH of the high voltage system power line 54a is adjusted within the range of the voltage VL of the battery voltage system power line 54b to the maximum allowable voltage VHmax, and the high voltage system power line 54a is connected to the battery voltage system power line 54b). Booster that exchanges power between the battery and the battery voltage system power line 54b A voltage sensor 58a for detecting the voltage of the path 56, the high voltage system power line 54a, a voltage sensor 58b for detecting the voltage of the battery voltage system power line 54b, an air conditioner 60 for air conditioning in the passenger compartment, and a battery voltage An air conditioning inverter 62 that is connected to the system power line 54b and drives the compressor 61 of the air conditioner 60, and a connection point Cn (see FIG. 2) between the negative terminal of the HV battery 50 and the system main relay SMR. Decrease in insulation resistance between the voltage system and the vehicle body based on a voltage waveform corresponding to an impedance (insulation resistance) between the voltage system as viewed from the connection point Cn and the grounded vehicle body (not shown). Insulation resistance reduction detector 90 for detecting the above and HVECU 70 for controlling the entire vehicle. Here, the voltage system includes motors MG1 and MG2, inverters 41 and 42, a booster circuit 56, an air conditioning inverter 62, an HV battery 50, and the like.

  Each of the motor MG1 and the motor MG2 is configured as a known synchronous generator motor including a rotor in which a permanent magnet is embedded and a stator around which a three-phase coil is wound. As shown in FIG. 2, the inverters 41 and 42 include six transistors T11 to T16 and T21 to 26, and six diodes D11 to D16 and D21 connected in parallel to the transistors T11 to T16 and T21 to T26 in the reverse direction. D26. Two transistors T11 to T16 and T21 to T26 are arranged in pairs so as to be on the source side and the sink side with respect to the positive and negative buses of the high voltage power line 54a, respectively. The three-phase coils (U-phase, V-phase, W-phase) of the motors MG1, MG2 are connected to the connection points. Therefore, the three-phase coil is controlled by controlling the on-time ratios of the transistors T11 to T16 and T21 to T26 that are paired in a state in which a voltage is applied between the positive electrode bus and the negative electrode bus of the high voltage power line 54a. Thus, a rotating magnetic field can be formed, and the motors MG1 and MG2 can be driven to rotate.

  The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, for example, rotation of the rotors of the motors MG1 and MG2 from a rotational position detection sensor (not shown) that detects the rotational position of the rotors of the motors MG1 and MG2. The position, the phase current applied to the motors MG1 and MG2 detected by a current sensor (not shown), the inverter temperature from a temperature sensor (not shown) attached to the inverters 41 and 42, and the like are input. Switching control signals to the transistors T11 to T16 and T21 to 26 of the inverters 41 and 42 are output. The motor ECU 40 is in communication with the HVECU 70, controls the driving of the motors MG1, MG2 by a control signal from the HVECU 70, and outputs data related to the operating state of the motors MG1, MG2 to the HVECU 70 as necessary.

  As shown in FIG. 2, the booster circuit 56 is configured as a boost converter including two transistors T31 and T32, two diodes D31 and D32 connected in parallel in the opposite direction to the transistors T31 and T32, and a reactor L. . The two transistors T31 and T32 are respectively connected to the positive bus of the high voltage system power line 54a and the negative bus of the high voltage system power line 54a and the battery voltage system power line 54b, and the reactor L is connected to the connection point. Has been. The positive terminal and the negative terminal of the HV battery 50 are connected to the reactor L and the negative bus of the battery voltage system power line 54b via the system main relay SMR, respectively. Therefore, by turning on / off the transistors T31 and T32, the power of the battery voltage system power line 54b is boosted and supplied to the high voltage system power line 54a, or the power of the high voltage system power line 54a is reduced to reduce the battery voltage. Or can be supplied to the system power line 54b.

  The HV battery 50 is connected to the battery voltage system power line 54b via the system main relay SMR. The system main relay SMR includes a positive side relay SMRB connected to the positive terminal of the HV battery 50 and the positive bus of the battery voltage system power line 54b, the negative terminal of the HV battery 50, and the negative bus of the battery voltage system power line 54b. And the resistor R and the negative relay SMRP connected in parallel to the negative relay SMRG between the negative terminal of the HV battery 50 and the negative bus of the battery voltage system power line 54b. And connected to. The positive side relay SMRB and the negative side relays SMRG and SMRP are controlled by the HVECU 70.

  The battery ECU 52 includes a signal necessary for managing the HV battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the HV battery 50, and a battery connected to an output terminal of the HV battery 50. The charging / discharging current from a current sensor (not shown) attached to the voltage system power line 54b, the battery temperature from a temperature sensor (not shown) attached to the HV battery 50, and the like are input, and the state of the HV battery 50 as necessary. Is output to the HVECU 70 by communication.

  As shown in FIG. 2, the air conditioning inverter 62 includes six transistors T41 to T46 and six diodes D41 to D46 connected in parallel to the transistors T41 to T46 in the reverse direction. The inverter is configured in the same manner as the inverters 41 and 42 except that it is connected to the battery voltage system power line 54b instead of the power line 54a.

  As shown in FIG. 2, the insulation resistance drop detector 90 includes an oscillation power source 92 grounded on one side, a detection resistor Rd connected on one terminal to the oscillation power source 92, and the other terminal on the other side of the detection resistor Rd. A coupling capacitor Cd having the other terminal connected to the connection point Cn and a voltage sensor 98 for detecting a voltage at a connection portion between the detection resistor Rd and the coupling capacitor Cd. FIG. 3 is an explanatory diagram showing an insulation resistance decrease detector 90 and a simplified model 99 of a system to which the insulation resistance decrease detector 90 is connected. Here, the simple model 99 is a circuit model when one or both of the positive side relay SMRB and the negative side relays SMRG, SMRP of the system main relay SMR are turned on, and one terminal is connected to the coupling capacitor Cd. The high-voltage insulation resistor Rs is connected and the other terminal is grounded, and the common-mode capacitor Cs is connected in parallel to the high-voltage insulation resistor Rs. The voltage waveform detected from the voltage sensor 98 has a voltage waveform with substantially the same amplitude as that of the oscillation power source 92 because almost no current flows through the detection resistor Rd when the impedance of the simple model 99 is large. Since the current flows through the detection resistor Rd when the voltage is small, the voltage waveform has a small amplitude corresponding to the voltage drop across the detection resistor Rd. Therefore, the voltage sensor 98 outputs a voltage waveform having substantially the same amplitude as that of the oscillation power source 92 when there is no leakage in the simplified model 99, that is, when the insulation resistance of the voltage system is not lowered. When this occurs, that is, when the insulation resistance of the voltage system is lowered, a voltage waveform having a smaller amplitude than that of the oscillation power source 92 is output. In the insulation resistance decrease detection of the embodiment, the signal from the insulation resistance decrease detector 90 is determined in advance by setting the amplitude of the voltage waveform detected from the voltage sensor 98 as a value slightly smaller than the amplitude of the voltage waveform of the oscillation power source 92. When the amplitude is larger than the amplitude for use, it is determined that the insulation resistance is not lowered and is normal, and when the amplitude of the voltage waveform detected from the voltage sensor 98 is smaller than the amplitude for judgment, the insulation resistance is lowered and abnormal. It was determined that there was.

  The resistance Rb in FIG. 2 is an insulation resistance between the voltage system (excluding the compressor 61) provided in the hybrid vehicle 20 and the vehicle body, and has a sufficiently high value when there is no abnormality in insulation resistance reduction. .

  The HVECU 70 is configured as a microprocessor centered on a CPU (not shown). In addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, And a communication port. The HVECU 70 includes a voltage VH from the voltage sensor 58a that detects the voltage of the high voltage system power line 54a, a voltage VL from the voltage sensor 58a that detects the voltage of the battery voltage system power line 54b, an ignition signal from the ignition switch, and a shift. Shift position SP from the shift position sensor that detects the lever operating position, accelerator opening Acc from the accelerator pedal position sensor that detects the depression amount of the accelerator pedal, and brake from the brake pedal position sensor that detects the depression amount of the brake pedal The pedal position BP, the vehicle speed V from the vehicle speed sensor, a signal (voltage waveform) from the insulation resistance drop detector 90, and the like are input via the input port. A switching control signal to the transistors T31 and T32 of the booster circuit 56, an on / off signal to the system main relay SMR, a switching control signal to the transistors T41 to T46 of the air conditioning inverter 62, and the like are output from the HVECU 70 through the output port. ing. As described above, the HVECU 70 also determines whether the insulation resistance is normal. Further, as described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. The voltage sensor 58a includes an internal capacitor Ch1 connected in parallel to the high voltage system power line 54 and internal resistors Rh1 and Rh2 connected in parallel between the terminals of the internal capacitor Ch1 and connected in series with each other. A connection point between the internal resistors Rh1 and Rh2 is grounded. The voltage sensor 58b includes an internal capacitor Cl connected in parallel to the battery voltage system power line 54b, and internal resistors Rl1 and Rl2 connected in parallel between the terminals of the internal capacitor Cl and connected in series with each other. A connection point between the internal resistors Rl1 and Rl2 is grounded.

  In the hybrid vehicle 20 of the embodiment thus configured, the required torque Tr * to be output to the drive shaft 36 is calculated based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque Tr * is output to the drive shaft 36.

  Next, the operation in the hybrid vehicle 20 of the embodiment, particularly, the operation when specifying the portion of the voltage system where the insulation resistance has decreased after detecting the decrease in the insulation resistance in the voltage system will be described. FIG. 4 is a flowchart showing an example of an insulation decrease detection processing routine executed by the HVECU 70. This process is executed when there is a Ready-OFF request for shutting off (turning off) the system main relay SMR in order to stop the vehicle system.

  When the insulation decrease detection processing routine is executed, the CPU of the HVECU 70 determines whether an insulation decrease abnormality in the voltage system is detected (step S100), whether an SMR check described later is incomplete (step S110), and SMR. Processing for determining whether or not processing other than checking is completed (step S120) is executed. Here, the detection of the insulation decrease abnormality in the process of step S100 is performed by executing the above-described insulation resistance decrease detection when the positive side relays SMRB and SMRG are connected (turned on) by ignition ON and the vehicle is activated. It was supposed to be done. Further, processing other than the SMR check in the processing of step S120 is, for example, processing for checking whether or not three relays (positive relay SMRB, negative relay SMRP, SMRG) included in the system main relay SMR are welded. , And various processes performed in response to a Ready-OFF request.

  When the insulation lowering abnormality is not detected, the SMR check is completed, or the processing other than the SMR check is not completed (steps S100 to S120), this routine is finished and the insulation lowering abnormality is detected. When the SMR check has not been completed and the processes other than the SMR check have been completed, the SMR check is started (step S130), and a process of comparing the low voltage side voltage VL with the determination threshold value V1 is executed. (Step S140). Here, in the SMR check, the negative side relays SMRG and SMRP are always turned off and the positive side relay SMRB is turned on and off. Further, the transistors T11 to T26 of the inverters 41 and 42 and the transistors T31, T32, In this process, the gates of the transistors T41 to T46 of the air conditioning inverter 62 are turned on or off (off) to detect the presence or absence of a decrease in the insulation resistance of each part of the voltage system. In particular, when detecting whether or not the insulation resistance on the HV battery 50 side is lowered from the air conditioning inverter 62, the positive side relay SMRB is turned on, and the transistors of the inverters 41 and 42, the booster circuit 56, and the air conditioning inverter 62 are turned on. In the state where the gates of T11 to T46 are cut off (turned off), the above-described insulation resistance reduction detection is executed. The determination threshold V1 is higher than the voltage obtained by adding the error of the voltage sensor 98 to the voltage at which each of the diodes D41 to D46 of the air conditioning inverter 62 is reverse-biased when a voltage is applied from the oscillation power supply 92. In the embodiment, since the HV battery 50 is 200 V, the determination threshold V1 is 180 V that is slightly lower than the rated voltage of the HV battery 50.

  When the low voltage side voltage VL is equal to or higher than the determination threshold value V1, the execution of the SMR check is continued (step S150), and this routine is terminated. Here, the reason why the execution of the SMR check is continued when the low voltage side voltage VL is equal to or higher than the determination threshold value V1 will be described.

  When the gate of the air conditioning inverter 62 is shut off (turned off) by the Ready-OFF request and the compressor 61 stops, the refrigerant stays in the air conditioner 60 and the capacity (common capacity) between the compressor 61 and the vehicle body. Cm may increase and impedance may decrease. At this time, the diodes D44 to D46 of the air conditioning inverter 62 may be turned on depending on the bias condition. When the insulation resistance reduction detection is executed in a state where the diodes D44 to D46 of the air conditioning inverter 62 are conductive, even when the insulation resistance is not actually lowered at the portion of the air conditioning inverter 62 on the HV battery 50 side, The amplitude of the signal detected by the voltage sensor 98 is different from the amplitude of the electric signal input from the oscillation power source 92, and it may be erroneously detected that the insulation resistance on the HV battery 50 side of the air conditioning inverter 62 is lowered. . When the low-voltage side voltage VL is the threshold value for determination V1, the voltages on the positive side and the negative side of the battery voltage system power line 54b are each set to the value V1 based on the ground potential (earth) by the internal resistances Rl1 and Rl2 of the voltage sensor 58b. / 2, (−V1 / 2), so that when the insulation resistance of the compressor 61 is lowered, each connection point between the upper arm and the lower arm of the air conditioning inverter 62 (transistor T41, diode D41, transistor T44, diode) D44, the connection point between the transistor T42, the diode D42 and the transistor T45, the connection point between the diode D45 and the connection point between the transistor T43, the diode D43 and the transistor T46, and the diode D46) are on the negative side of the battery voltage system power line 54b. The diodes D44 to D46 are conducted. A state that does not. Thus, by performing the SMR check when the low voltage side voltage VL is equal to or higher than the determination threshold value V1, the SMR check can be performed in a state where the diodes D44 to D46 of the air conditioning inverter 62 are not conductive. It is possible to suppress erroneous detection of a decrease in insulation resistance on the HV battery 50 side of 62.

  When the low voltage side voltage VL is smaller than the determination threshold value V1, it is determined that the diodes D44 to D46 of the air conditioning inverter 62 may be turned on, and if the SMR check is being executed, it is temporarily suspended (step S160). Then, both the positive side relay SMRB and the negative side relay SMRG are turned on, and the internal capacitor Cl is charged until the battery voltage system power line 54b becomes a voltage V2 (for example, the rated voltage of the HV battery 50) equal to or higher than the determination threshold value V1. After executing the charge, the SRM check is resumed (step S170), and this routine is terminated. By such processing, when the execution of this routine is started, when the low voltage side voltage VL is lower than the determination threshold value V1, or when the voltage of the battery voltage system power line 54b is lowered during the execution of the SMR check, the battery voltage system The SMR check can be executed by setting the power line 54b to a voltage V2 that is equal to or higher than the determination threshold value V1.

  In the hybrid vehicle 20 of the embodiment described above, when the insulation resistance of the voltage system is detected and the voltage of the battery voltage system power line 54b is equal to or higher than the determination threshold value V1, the execution of the SMR check is continued. By doing so, it can suppress that the fall of the insulation resistance by a refrigerant | coolant stagnating in the air conditioner 60 is mistakenly detected as the insulation fall by the side of the HV battery 50 of the inverter 52 for an air conditioning.

  In the hybrid vehicle 20 of the embodiment, the voltage VL of the battery voltage system power line 54b is compared with the determination threshold value V1 after the SMR check is started in the process of step S130. However, the battery is used to start the SMR check. The voltage VL of the voltage system power line 54b may be compared with the determination threshold value V1.

  In the hybrid vehicle 20 of the embodiment, the SMR check is started in the process of step S130 after confirming that the processes other than the SMR check are completed in the process of step S120, but the negative relay SMRG is welded. Since the SMR check cannot be properly performed when it is present, it is determined whether or not the negative relay SMRG is welded before the SMR check is started, as shown in the insulation drop detection routine of the modification of FIG. Also good. In this case, instead of the processing of steps S120 and S130 of FIG. 2, when the welding check of the negative side relay SMRG is incomplete and starts (step S220), the negative side relays SMRG and SMRP are turned off and the positive side relay SMRB is turned off. In a state where only the system main relay SMR is controlled so that only the motor MG1 is turned on, an SMR welding check is performed in which at least one of the motors MG1 and MG2 is operated to discharge the internal capacitor Ch (step S230). It is checked whether or not the threshold value V1 has decreased to the threshold value V1 (step S240). When the voltage VL decreases to the determination threshold value V1 after a certain time, there is no possibility that the negative relay SMRG is welded, and the SMR check is performed. SMR check is executed (step S150). When the voltage VL does not drop to the determination threshold V1 after a certain time, it is determined that the negative relay SMRG may be welded, and the welding of the negative relay SMRG is determined without performing the SMR check. The SMR welding determination may be executed (step S260). By doing so, it is possible to suppress the SMR check from being performed while the negative relay SMRG is welded, and to perform the SMR check with the voltage VL being set to the determination threshold value V1.

  In the hybrid vehicle 20 of the embodiment, the SMR check is a process in which the negative side relays SMRG and SMRP are always turned off and the positive side relay SMRB is turned on and off to detect the presence or absence of a decrease in the insulation resistance of each part. The one side pole of the system main relay SMR may be always off and the opposite pole may be turned on / off. For example, the positive side relay SMRB may be always turned off and only the negative side relay SMRG may be turned on / off.

  In the hybrid vehicle 20 of the embodiment, in the process of step S140, the voltage sensor 98 is set to a voltage at which each of the diodes D41 to D46 of the air conditioning inverter 62 is reverse-biased when the threshold voltage for determination V1 is applied from the oscillation power supply 92. Although it is assumed that the voltage is higher than the voltage to which the error is added, any voltage may be used as long as the diodes D41 to D46 of the air conditioning inverter 62 are turned off. For example, when the voltage is applied from the oscillation power source 92, the air conditioning inverter A voltage obtained by adding an error of the voltage sensor 98 to a voltage at which each of the 62 diodes D41 to D46 is reverse-biased may be used.

  In the embodiment, the present invention is applied to a hybrid vehicle equipped with the engine 22 and the motors MG1 and MG2 as a driving power source. However, the driving power is not provided with the engine 22 and the motor MG1. It may be applied to an electric vehicle having only a motor as a source.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor MG2 corresponds to “motor”, the HV battery 50 corresponds to “battery”, the booster circuit 56 corresponds to “boost circuit”, the air conditioner 60 corresponds to “air conditioner”, the system The main relay SMR corresponds to a “system main relay”, the air conditioning inverter 62 corresponds to an “air conditioning inverter”, and the insulation resistance decrease detector 90 and the HVECU 70 correspond to an “insulation decrease detection device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of electric vehicles.

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 40 motor electronic control unit (motor ECU), 41, 42 Inverter, 50 HV battery, 52 Battery electronic control unit (battery ECU), 54a High voltage system power line, 56 Booster circuit, 58a, 58b, 98 Voltage sensor, 60 Air conditioner, 61 Compressor, 62 Air conditioner inverter , 70 Hybrid electronic control unit (HVECU), 90 Insulation resistance drop detector, 92 Oscillation power supply, Cd coupling capacitor, Ch, Cl internal capacitor, Cn connection point, D11 to D16, D21 to D2 , D41 to D46 Diode, L reactor, MG1, MG2 motor, SMR system main relay, SMRB positive side relay, SMRG, SMRP negative side relay, Rd detection resistor, Rh1, Rh2, Rl1, Rl2 internal resistance, T11 to T16, T21 T26, T31, T32, T41 to T46 transistors.

Claims (1)

A motor, a battery, a booster circuit that boosts electric power supplied from the battery and supplies the booster to the motor, an air conditioner having a compressor that compresses refrigerant, and the battery and the booster circuit are connected A voltage system including a system main relay, an air conditioning inverter connected to a power line connecting the system main relay and the booster circuit, and driving the compressor; on / off of the system main relay; An insulation decrease detection device that performs insulation decrease detection that detects a decrease in insulation resistance by application of an electrical signal connected to a negative electrode;
When the insulation drop of the voltage system is detected, the insulation drop detection device performs the insulation drop detection by turning off the gate of the air conditioning inverter in a state where the voltage of the power line is equal to or higher than a predetermined voltage. An electric vehicle.

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