JP2012165536A - Electric vehicle - Google Patents

Abstract

The present invention relates to a method for identifying a site where a decrease in insulation resistance occurs more appropriately.
An electric system as a circuit including a part of or all of a motor, an air conditioner, and a battery according to each state of an inverter for driving a driving motor, an inverter for an air conditioner, and a system main relay. After detecting a decrease in the insulation resistance of the system and detecting a decrease in the insulation resistance of the electric system, which of the three areas of the motor area, the air conditioner area, and the battery area has a decrease in the insulation resistance? The motor area specifying process, the air conditioner area specifying process, and the battery area specifying process are executed so as to specify whether or not there is (S240, S280, S320). If it is impossible to identify the part where the insulation resistance has decreased due to the execution of such specific processing, the part where the insulation resistance has decreased relative to the part that caused the unspecified after the system was started next time The identification process for each area is executed again so that it can be identified.
[Selection] Figure 4

Description

  The present invention relates to an electric vehicle, and in particular, an electric motor capable of outputting driving power, an electric motor drive circuit for driving the electric motor, an auxiliary machine, an auxiliary machine drive circuit for driving the auxiliary machine, and an electric motor The present invention relates to an electric vehicle including a power storage device that outputs power to a drive system to which a drive circuit and an auxiliary drive circuit are connected, and a connection release unit that connects and disconnects the power storage device and the drive system.

  Conventionally, this type of electric vehicle includes a motor generator capable of outputting driving power, an inverter that drives the motor generator, an air conditioner compressor, an air conditioner inverter that drives the air conditioner compressor, an inverter and an air conditioner inverter. A power storage device that supplies power to the motor generator and the air conditioner compressor, a system main relay that connects the power storage device to the inverter side, and a low insulation resistance detector that is connected to the negative electrode side of the power storage device. Using a detector, it is possible to identify the part where the insulation resistance has dropped from multiple parts such as the part on the motor generator side from the inverter, the part on the air conditioner compressor side from the air conditioner inverter, and the part on the power storage device side from the system main relay. Has been proposed For example, see Patent Document 1). The vehicle further includes a charging port that receives power from a charging cable connected to a power source outside the vehicle for charging the power storage device, and uses the insulation resistance lowering detector to detect the charging port and a plurality of predetermined parts in the traveling mode. It is possible to identify a part where the insulation resistance is reduced from a part including

JP 2009-261133 A

  However, in the above-described electric vehicle, during the process of specifying the part where the insulation resistance is reduced, for example, the leakage is temporarily eliminated or the insulation resistance is reduced due to the noise generated in the circuit. In some cases, the voltage acting on the detector may fluctuate and it may fail to identify the site where the insulation resistance is reduced. In this case, there is a possibility that inconveniences such as it may not be possible to immediately repair the leakage site when maintaining the vehicle, or it may be necessary to re-execute identification processing of the portion where the insulation resistance has decreased. It was.

  The main object of the electric vehicle of the present invention is to more appropriately identify the portion where the insulation resistance is reduced.

  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
An electric motor capable of outputting driving power, an electric motor drive circuit for driving the electric motor, an auxiliary machine, an auxiliary machine drive circuit for driving the auxiliary machine, the electric motor drive circuit, and the auxiliary machine drive An electric vehicle comprising: a power storage device that supplies power to a drive system to which a circuit is connected; and connection release means for connecting and releasing the connection between the power storage device and the drive system,
Insulation resistance of the circuit with respect to a circuit including a part or all of the electric motor, the auxiliary machine, and the power storage device according to each state of the electric motor driving circuit, the auxiliary driving circuit, and the connection release means Insulation resistance decrease detection means for detecting a decrease in
A portion where a decrease in the insulation resistance of the circuit occurs among a plurality of portions including the electric motor, the auxiliary device, and the power storage device after a decrease in the insulation resistance of the circuit is detected by the insulation resistance decrease detecting means. The first specific control for controlling the motor drive circuit, the auxiliary drive circuit, and the connection release means is executed so that it is specified, and the circuit is also executed by executing the first specific control. When the part where the insulation resistance declined cannot be specified When the part cannot be specified, the insulation resistance of the circuit has dropped with respect to the part causing the unspecified after the system was started next time Part specifying control means for executing second specifying control for controlling the electric motor drive circuit, the accessory drive circuit, and the connection release means so that the part is specified;
It is a summary to provide.

  In the electric vehicle according to the present invention, circuit insulation is provided for a circuit including a part or all of the electric motor, the auxiliary machine, and the power storage device in accordance with the states of the electric motor driving circuit, the auxiliary machine driving circuit, and the connection release means. Which part of the plurality of parts including the electric motor, the auxiliary machine, and the power storage device has undergone a drop in the insulation resistance of the circuit after the drop in the resistance is detected. The first specific control for controlling the motor drive circuit, the auxiliary drive circuit, and the connection release means is executed. Then, when the part where the insulation resistance of the circuit has decreased due to the execution of the first specific control cannot be specified, the part that caused the unspecified after the system is started next time The second specific control is executed to control the motor drive circuit, the auxiliary drive circuit, and the connection release means so that it is specified which part has caused a decrease in the insulation resistance of the circuit. Therefore, when the part cannot be specified, the control for specifying the part where the insulation resistance is reduced is executed with respect to the part causing the specification failure. Therefore, the control for specifying the part where the insulation resistance is reduced is performed only once. It is possible to more reliably identify the part where the insulation resistance is reduced compared to those not performed, and to reduce the insulation resistance for a plurality of parts including parts other than the part causing the unidentification. It is possible to make the control simpler than that in which the control for specifying the site where the occurrence occurs is performed again. As a result, it is possible to more appropriately identify the part where the insulation resistance is reduced.

  In such an electric vehicle according to the present invention, the first specific control is performed so as to determine whether or not each of the plurality of parts is a part where a decrease in the insulation resistance of the circuit occurs. Yes, when the part cannot be specified includes when it is determined that the insulation resistance of the circuit has been lowered for two or more parts of the plurality of parts by executing the first specific control, In the second specific control, it is determined whether or not each of the two or more portions as the portion causing the unspecified state is a portion where a decrease in the insulation resistance of the circuit has occurred. It is also possible to control. By so doing, it is possible to more reliably identify the portion where the insulation resistance has been lowered.

  In the electric vehicle according to the aspect of the present invention in which it is determined whether each of these is a portion where a decrease in the insulation resistance of the circuit has occurred, the first specific control is performed by the insulation resistance decrease detecting unit from the plurality of portions. Control is performed so as to determine whether or not each of the parts excluding the non-energized part that was not energized when a decrease in the insulation resistance of the circuit is detected is a part where the insulation resistance of the circuit is generated. It can also be. If it carries out like this, when performing 1st specific control and 2nd specific control, the target range which should be specified can be narrowed more and control can be made simpler.

  Further, in the electric vehicle according to the present invention, the first specific control and the second specific control include energization and energization stop of the electric motor, energization and energization stop of the auxiliary machine, connection to the drive system of the power storage device, and It is also possible to control so as to specify which portion of the circuit has an insulation resistance by at least one of the release of the connection.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 3 is an explanatory diagram illustrating a configuration of a voltage waveform output circuit 90. FIG. It is a flowchart which shows an example of the insulation resistance fall detection processing routine performed by the electronic control unit for hybrid 70 of an Example. It is a flowchart which shows an example of the insulation resistance fall site | part specific process routine performed by the hybrid electronic control unit 70 of an Example. It is a flowchart which shows an example of a motor area specific process. It is a flowchart which shows an example of an air-conditioner area specific process. It is a flowchart which shows an example of a battery area specific process. It is a block diagram which shows the outline of a structure of the electric vehicle 120 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 the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 that uses gasoline, light oil, or the like as fuel, and an engine electronic control unit that operates the engine 22 by fuel injection control, ignition control, intake air amount control, or the like (hereinafter referred to as an engine control unit). A planetary gear in which a carrier is connected to a crankshaft 26 as an output shaft of the engine 22 and a ring gear is connected to a drive shaft 32 connected to drive wheels 36a and 36b via a differential gear 34. 30, a motor MG1 configured as a synchronous generator motor and having a rotor connected to the sun gear of the planetary gear 30, a motor MG2 configured as a synchronous generator motor and connected to the drive shaft 32, and a motor MG1. , Inverters 41 and 42 for driving MG2; A motor electronic control unit (hereinafter referred to as a motor ECU) 40 that controls the driving of the motors MG1 and MG2 by switching control of switching elements (not shown) of the inverters 41 and 42, and an inverter 41 configured as, for example, a lithium ion secondary battery. , 42 is connected to a drive system power line 56, a battery 50 that exchanges power, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 that manages the battery 50, and the battery 50 and the drive system power line 56. System main relay 54 that connects and disconnects (shuts off), smoothing capacitor 58 that is connected to the positive and negative buses of drive system power line 56, and an electric compressor that is included in the air conditioner that air-conditions the passenger compartment ( 60) and air conditioner Motors MG1, MG2 and inverters 41, 42 connected to a connection point Cn between the negative terminal of the battery 50 and the system main relay 54, connected to the drive system power line 56 to drive 0. , An air conditioner 60, an air conditioner inverter 62, a system main relay 54, a voltage waveform output circuit 90 that outputs a voltage waveform corresponding to the insulation resistance of an electric system including part or all of the battery 50, and a hybrid that controls the entire vehicle And an electronic control unit 70.

  Here, when the system main relay 54 is on, the electric system is driven when the motors MG1 and MG2 are driven by the drive of the inverters 41 and 42 and the air conditioner 60 is driven by the drive of the inverter 62 for the air conditioner (hereinafter, referred to as “electrical system”). In the case of full driving), the circuit includes all of the motors MG1, MG2, inverters 41, 42, air conditioner 60, air conditioner inverter 62, system main relay 54, and battery 50. For example, when the inverters 41 and 42 are gate-cut at the time of full drive, the electrical system becomes a circuit including a connection point Cn excluding the motor area on the motor MG1 and MG2 side from the inverters 41 and 42 from the circuit at the time of full drive. When the air conditioner inverter 62 is gate-cut during full driving, the electrical system is a circuit including a connection point Cn obtained by removing the air conditioner area on the air conditioner 60 side from the air conditioner inverter 62 from the circuit during full driving. When the system main relay 54 is turned off, the electric system becomes a battery area as a circuit including the connection point Cn on the battery 50 side from the system main relay 54. Motors MG1 and MG2 included in the motor area are housed in a common case, and each area such as the motor area, the air conditioner area, and the battery area is insulated from each other independently.

  As shown in FIG. 2, the voltage waveform output circuit 90 is connected to an oscillator 92 that is grounded and generates a pulse of a constant frequency (for example, a rectangular wave, a sine wave, a triangular wave, etc.), and one terminal is connected to the oscillator 92. The detection resistor 94, the capacitor 95 connected to the other terminal of the detection resistor 94 and the connection point Cn, and the connection point Co between the detection resistor 94 and the capacitor 95 are connected to the high frequency component to remove the signal. A low-pass filter 96 that outputs to the hybrid electronic control unit 70, and outputs a signal (voltage waveform) to the hybrid electronic control unit 70 in accordance with the relationship between the resistance value of the detection resistor 94 and the resistance value of the electrical system described above. To do. The voltage waveform from the voltage waveform output circuit 90 becomes a voltage waveform having substantially the same amplitude as that of the oscillator 92 when the insulation resistance of the electric system is not lowered (when there is no risk of leakage), and the insulation resistance of the electric system Is reduced (when there is a risk of electric leakage), a voltage waveform having a smaller amplitude than that of the oscillator 92 is generated due to a voltage drop at the detection resistor 94. Therefore, in the hybrid electronic control unit 70 according to the embodiment, the amplitude of the voltage waveform from the voltage waveform output circuit 90 is equal to the voltage waveform of the oscillator 92 as an insulation determination for determining whether the electrical insulation resistance is normal. The electrical insulation resistance is determined to be normal when it is equal to or greater than the determination threshold value determined as a value slightly smaller than the amplitude, and when the voltage waveform from the voltage waveform output circuit 90 is smaller than the determination threshold value, the electrical insulation resistance is It was determined to be lowered (abnormal).

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, and a non-volatile that holds the stored data. Flash memory 78 and an input / output port and a communication port (not shown). The hybrid electronic control unit 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal. The accelerator opening Acc, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal, the vehicle speed V from the vehicle speed sensor 88, the signal from the voltage waveform output circuit 90, etc. are input via the input port. ing. From the hybrid electronic control unit 70, a drive signal for turning on / off the system main relay 54, a control signal for switching control of the inverter 62 for the air conditioner, a lighting signal for the warning lamp 89 mounted in front of the driver's seat, and the like are output via the output port. Is output. The hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via a communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

  The hybrid vehicle 20 of the embodiment configured as described above calculates a required torque to be output to the drive shaft 32 based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver, and this required torque. The engine 22, the motor MG 1, and the motor MG 2 are controlled to be operated so that the required power corresponding to is output to the drive shaft 32. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. And the motor MG2 convert the torque and output to the drive shaft 32. The torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 are obtained. The operation of the engine 22 is controlled so as to be output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. Accordingly, the required power is output to the drive shaft 32. Charge-discharge drive mode for driving and controlling the motor MG1 and the motor MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 32.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when specifying the portion where the insulation resistance of the electric system has been reduced will be described. FIG. 3 is a flowchart showing an example of an insulation resistance decrease detection processing routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed at predetermined time intervals when the system main relay 54 is on in a state where the vehicle is activated by ignition on.

  When the insulation resistance lowering detection processing routine is executed, the CPU 72 of the hybrid electronic control unit 70 first checks the abnormality detection flag Fdet in which the value 0 is set as the initial value and the value 1 is set in this routine (step S100). ) When the abnormality detection flag Fdet is 0, electrical insulation is determined (step S110). When the insulation resistance is abnormal, the abnormality detection flag Fdet is set to 1 (step S120). Here, the electrical insulation determination is performed by comparing the amplitude of the voltage waveform from the voltage waveform output circuit 90 with a determination threshold. In the embodiment, the abnormality detection flag Fdet is stored in the flash memory 78. Once the value 1 is set, the set value 1 is held unless the value is reset during maintenance of the vehicle. In the embodiment, when the abnormality detection flag Fdet is 1, the warning lamp 89 is turned on. In the following, various flags used in the insulation resistance reduction detection process and the insulation resistance reduction part identification process are also stored in the flash memory 78 in the same manner as the abnormality detection flag Fdet. Once the value 1 is set, Unless it is reset at the time of maintenance or the like, the set value 1 is held.

  Thus, when the value 1 is set in the abnormality detection flag Fdet, the value 0 is set as an initial value, and each area of the motor area, the air conditioner area, and the battery area indicates that there is a possibility of electric leakage. The flags Fm1, Fa1, and Fb1 are set (step S130), and the insulation resistance decrease detection processing routine is terminated. Here, the leakage possibility flag Fm1 in the motor area indicates that the motor area is detected when one or both of the motors MG1 and MG2 are driven by the inverters 41 and 42 when it is determined in step S110 that the insulation resistance is abnormal. Since the value 1 is set because there is a possibility of electric leakage, and when it is determined in step S110 that the insulation resistance is abnormal, when both inverters 41 and 42 are gate-cut off, electric leakage is possible in the motor area. It was assumed that the value 0 was retained because there was no property. The states of the inverters 41 and 42 can be determined based on signals input from the motor ECU 40 through communication. The air conditioner area leakage potential flag Fa1 indicates that there is a possibility of electric leakage in the air conditioner area when the air conditioner 60 is driven by the air conditioner inverter 62 when it is determined in step S110 that the insulation resistance is abnormal. Therefore, when the value 1 is set and the air conditioner inverter 62 is gate-cut when it is determined in step S110 that the insulation resistance is abnormal, the value 0 is maintained because there is no possibility of leakage in the air conditioner area. It was supposed to be. The leakage potential flag Fb1 in the battery area is set to a value of 1 in step S130 because the system main relay 54 is turned on when it is determined in step S110 that the insulation resistance is abnormal.

  If the insulation resistance is normal when the abnormality detection flag Fdet has a value of 0 in steps S100 and S110, the abnormality detection flag Fdet having a value of 0 and the potential leakage flags Fm1, Fa1, Fb1 of each area having a value of 0 are stored in the flash memory 78. The insulation resistance drop detection processing routine is terminated while holding

  In addition, once the value 1 is set in the abnormality detection flag Fdet, the value of the abnormality detection flag Fdet having the value 1 and the value for each area are stored in the flash memory 78 according to the determination result in step S100 when this routine is executed next time. The insulation resistance lowering detection processing routine is terminated while holding the leakage potential flag Fm1, Fa1, Fb1 for which is set. Therefore, once the value 1 is set to the abnormality detection flag Fdet in the state where the system is activated, the value is set to the abnormality detection flag Fdet of value 1 and each area unless the abnormality detection flag Fdet is reset at the time of vehicle maintenance or the like. The set leakage potential flags Fm1, Fa1, Fb1 are held in the flash memory 78. In the above, the detection process of the electrical insulation resistance fall was demonstrated.

  Next, a description will be given of a process for identifying a site where a decrease in insulation resistance of the electric system occurs. FIG. 4 is a flowchart showing an example of the insulation resistance lowering portion specifying process routine executed by the hybrid electronic control unit 70. This routine is executed when an instruction to stop the system of the vehicle is given by turning off the ignition. In this embodiment, before executing this routine, so-called zero torque control is performed so that torque is not output from the motors MG1 and MG2 and the air conditioner 60 does not operate (rotate) with the system main relay 54 turned on. It is assumed that the inverters 41 and 42 and the air conditioner inverter 62 are driven.

  When the insulation resistance lowering portion specifying process routine is executed, the CPU 72 of the hybrid electronic control unit 70 first checks the abnormality detection flag Fdet stored in the flash memory 78 (step S200), and the abnormality detection flag Fdet is 0. In this case, since the insulation resistance is normal, the insulation resistance lowering portion specifying process routine is finished as it is. Thereafter, the inverters 41 and 42 and the inverter 62 for the air conditioner are turned off, and the system main relay 54 is turned off to stop the vehicle.

  When the abnormality detection flag Fdet is 1, it is determined whether or not the process for specifying the insulation resistance lowering portion has been completed for each of the motor area, the air conditioner area, and the battery area (step S210). In this embodiment, this determination is performed by a specific process completion flag Fmfin, Fafin, Fbfin in which a value 0 is set as an initial value for each area of the motor area, the air conditioner area, and the battery area, and a value 1 is set when the specific process is completed. Is determined by determining whether or not each has a value of 1.

  As a result of this determination, when it is determined that there is an uncompleted area, the leakage possibility flag Fm1 and the specific process completion flag Fmfin in the motor area are checked (steps S220 and S230), and the leakage possibility flag Fm1 is 1. When the specific process completion flag Fmfin is 0, it is determined that the specific process needs to be executed because there is a possibility of electric leakage in the motor area, and the motor area specific process is executed (step S240). A value 1 is set to the specific process completion flag Fmfin (step S250).

  When the motor area leakage possibility flag Fm1 is 0, it is determined that there is no possibility of leakage in the motor area and therefore it is not necessary to execute the specific process. 1 is set to the specific process completion flag Fmfin (step S250). Further, even when the motor area leakage possibility flag Fm1 is the value 1, when the specific process completion flag Fmfin is the value 1, since the motor area specifying process is completed, the processes after step S260 are executed.

  In the motor area specifying process, as illustrated in FIG. 5, by instructing the motor ECU 40, the inverters 41 and 42 are gated to determine the insulation of the electric system (steps S400 and S410), and the insulation resistance is normal. Sometimes, by instructing the motor ECU 40, the inverters 41 and 42 are driven again to determine the insulation of the electric system (steps S420 and S430). When the insulation resistance is abnormal, a value 0 is set as an initial value. A value 1 is set to the leakage specifying flag Fm2 indicating that the motor area is a leakage portion (step S440), and the specifying process is terminated. In other words, when the motor area is disconnected from the electrical system, the insulation resistance is normal, and when the motor resistance is changed from normal to abnormal when the motor area is included in the electrical system again, the motor area is identified as a leakage site. To do. Therefore, when the insulation resistance is abnormal in step S410 or step S430, it is determined that the motor area is not an electric leakage part, and the specific process is terminated while the electric leakage specific flag Fm2 having a value of 0 is held.

  Returning to the description of the insulation resistance lowering portion specifying process in FIG. When the motor area specifying process is completed and the motor area specifying process completion flag Fmfin is set to a value of 1, the leakage potential flag Fa1 and the specifying process completion flag Fafin in the air conditioner area are checked (steps S260 and S270). When the leakage possibility flag Fa1 is 1 and the specific process completion flag Fafin is 0, it is determined that the specific process needs to be executed because there is a possibility of electric leakage in the air conditioner area, and the air conditioner area specific process is executed. (Step S280), the value 1 is set to the specific processing completion flag Fafin of the air conditioner area (step S290).

  When the leakage possibility flag Fa1 in the air conditioner area is 0, it is determined that the specific process is not necessary because there is no possibility of a leak in the air conditioner area, and the specific process is considered to be completed. A value 1 is set to the specific processing completion flag Fafin (step S290). Further, even when the leakage possibility flag Fa1 of the air conditioner area is the value 1, when the specific process completion flag Fafin is the value 1, the air conditioner area specifying process has been completed, and thus the processes after step S300 are executed.

  In the air conditioner area specifying process, as shown in FIG. 6, the air conditioner inverter 62 is gated and the insulation of the electric system is determined (steps S500 and S510). When the insulation resistance is normal, the air conditioner inverter 62 is turned on. When the insulation resistance of the electric system is abnormal by driving again to determine the insulation of the electric system (steps S520 and S530), the value 0 is set as an initial value and the leakage specifying flag Fa2 indicating that the air conditioner area is a leakage portion Is set to 1 (step S540), and the specifying process is terminated. In other words, when the insulation resistance is normal when the air conditioner area is disconnected from the electrical system, and the insulation resistance changes from normal to abnormal when the air conditioner area is included in the electrical system again, the air conditioner area is identified as a leakage site. To do. Therefore, when the insulation resistance is abnormal in step S510 or step S530, it is determined that the air conditioner area is not an electric leakage part, and the specifying process is terminated while the electric leakage specifying flag Fa2 having a value of 0 is held.

  Returning to the description of the insulation resistance lowering portion specifying process in FIG. When the air conditioner area specifying process is finished and the value 1 is set in the air conditioner area specifying process completion flag Fafin, the leakage potential flag Fb1 and the specific process completion flag Fbfin in the battery area are checked (steps S300 and S310). When the leakage possibility flag Fb1 is 1 and the specific process completion flag Fbfin is 0, it is determined that the specific process needs to be executed because there is a possibility of leakage in the battery area, and the battery area specifying process is executed. (Step S320), a value 1 is set to the battery area identification process completion flag Fbfin (step S330).

  When the leakage potential flag Fb1 in the battery area is 0, it is not assumed in the embodiment, but at this time, it is determined that there is no possibility of leakage in the battery area, and therefore it is not necessary to execute the specific process. Is set to 1 in the battery area specific process completion flag Fbfin (step S330). Further, even when the battery area leakage flag Fb1 is the value 1, when the specific process completion flag Fbfin is the value 1, the battery area specifying process is completed, and therefore, the processes after step S340 are executed.

  In the battery area specifying process, as illustrated in FIG. 7, the inverters 41 and 42 and the air conditioner inverter 62 are brought into a drive stop state, and the system main relay 54 is turned off to determine the insulation of the electric system (step S600). , S610), when the insulation resistance is abnormal, a value of 0 is set as an initial value, and a value of 1 is set in a leakage detection flag Fb2 indicating that the battery area is a leakage region (step S620). Exit. That is, even if an area other than the battery area is disconnected from the electrical system, the battery area is specified as a leakage site when the insulation resistance is abnormal. Therefore, when the insulation resistance is abnormal in step S610, it is determined that the battery area is not a leakage site, and the specific process is terminated while holding the leakage specification flag Fb2 having a value of 0. At this time, in the embodiment, the system main relay 54 is turned on again.

  Thus, by setting the leakage detection flags Fm2, Fa2, Fb2 in the motor area, the air conditioner area, and the battery area, and setting the specific processing completion flags Fmfin, Fafin, Fbfin in each area, it is possible to specify the leakage area. It is determined whether or not there is (step S340). In this embodiment, this determination is made when any one of the leakage specification flags Fm2, Fa2, and Fb2 in each area has a value of 1, and is specified when two or three flags have a value of 1. It was determined that it was impossible, and it was determined that it was not possible to specify any flag when the value was 0.

  When the leakage site can be specified, data indicating the specified leakage site is stored in the flash memory 78 to determine an area corresponding to the leakage site (step S350), and when the leakage site cannot be specified. Then, the earth leakage specifying flag and the specifying process completion flag of the area that caused the specifying failure are reset to 0 (step S360), and the insulation resistance lowering part specifying process routine is ended.

  The current leakage that has occurred once is temporarily eliminated by vibration or the like, or the voltage acting on the voltage waveform output circuit 90 fluctuates due to the influence of noise generated in the electrical system, etc. Let us consider a case where the leakage determination flags Fa2 and Fb2 are set to the value 1 in the two areas. In this case, when the system is activated with the ignition turned on (such as when the vehicle is running), a decrease in insulation resistance in any part of the electrical system is detected, and each area is instructed to stop the system with the ignition turned off. In the embodiment, as a result of executing the specific processing of each area excluding the non-energized portion where the value 1 was not set in the leakage potential flag when the insulation resistance drop was detected, A case where the value 1 is set in the confirmation flags Fa2 and Fb2 is conceivable. In this case, in a state where the system is activated next by the ignition being turned on (such as when the vehicle is running), it is determined that the abnormality detection flag Fdet is 1 in the insulation resistance reduction detection process of FIG. After that, when the system stop is instructed due to the ignition off, it is determined that the abnormality detection flag Fdet is a value of 1 in the insulation lowering part specifying process of FIG. A specific process, that is, an air conditioner area specific process and a battery area specific process, are performed on the two areas that caused the unspecified condition. As a result of these identification processes, if the area corresponding to the leakage site is determined, the identification process for each area will not be executed unless the various flags are reset at the time of vehicle maintenance after the system is next activated. .

  In this way, when the leakage site cannot be specified, the specific process is re-executed by narrowing down to the part that caused the non-specification, so that the specific process is performed again for all three areas. Thus, the processing can be simplified. In addition, it is possible to more reliably identify the portion where the insulation resistance is reduced, as compared to the case where the leakage current portion is identified only once and remains in an unidentifiable state. As a result, it is possible to more appropriately identify the portion where the insulation resistance is reduced. Further, whether or not the area is a leakage site for each area, with the connection and disconnection of the area by driving and shutting off the inverters 41 and 42, driving and shutting off the inverter 62 for the air conditioner, turning on and off the system main relay 54, etc. Since it is determined whether or not, it is possible to more reliably identify the part where the insulation resistance is reduced. In addition, when a decrease in insulation resistance is detected, it is determined whether or not the area is a leakage site for the area excluding the non-energized portion that was not energized. It is possible to simplify the processing when executing or executing the specific processing of each area again.

  In the hybrid vehicle 20 of the embodiment described above, some or all of the motors MG1, MG2, the air conditioner 60, and the battery 50 are included depending on the states of the inverters 41, 42, the air conditioner inverter 62, and the system main relay 54. For the electrical system as a circuit, a decrease in the insulation resistance of the electrical system is detected, and after the decrease in the insulation resistance of the electrical system is detected, the insulation resistance of the three parts of the motor area, the air conditioner area, and the battery area is detected. The motor area specifying process, the air conditioner area specifying process, and the battery area specifying process are executed so that it is specified which part has been reduced. If the part where the insulation resistance has decreased due to the execution of such specific processing cannot be specified, the insulation resistance will decrease with respect to the part that caused the unspecified after the next system startup. The identification process for each area is executed again so that the identified part is identified. Thereby, the site | part which the fall of insulation resistance produced can be specified more appropriately.

  In the hybrid vehicle 20 of the example, it was determined whether or not the area other than the non-energized portion that was not energized when a decrease in insulation resistance was detected, but the insulation resistance decreased It is good also as what determines whether it is an electrical leakage site | part about all the areas irrespective of whether it was supplied with electricity, when is detected. In this case, it is not necessary to set or determine the leakage potential flags Fm1, Fa1, and Fb1 in each area.

  In the hybrid vehicle 20 of the embodiment, the process of specifying the leakage site is performed from the three areas of the motor area, the air conditioner area, and the battery area. In these three areas, the inverters 41 and 42, the inverter for the air conditioner are provided. It is good also as what carries out the process which specifies an electrical leakage site | part from four areas which added the direct current | flow area between 62 and the system main relay 54, and specifies an electrical leakage site | part from four or more areas by adding another site | part. Processing may be performed.

  In the hybrid vehicle 20 of the embodiment, the air conditioner area closer to the air conditioner 60 than the inverter 62 for the air conditioner is one of the objects of the processing for specifying the leakage site. However, instead of or in addition to the air conditioner area, a DC / DC (not shown) The auxiliary motor area on the side of the auxiliary motor from the converter may be one of the targets for the processing for identifying the leakage site.

  In the embodiment, the present invention is applied to the hybrid vehicle 20 that travels using the power output from the engine 22 and the motor MG1 to the drive shaft 32 via the planetary gear 30 and the power output from the motor MG2 to the drive shaft 32. As described above, as exemplified in the hybrid vehicle that travels using the power directly output from the engine to the drive shaft and the power output from the motor to the drive shaft, and the electric vehicle 120 of the modified example of FIG. The present invention may be applied to a vehicle that travels by power from a motor MG driven by an inverter 142 without including an engine.

  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 the “motor”, the inverter 42 corresponds to the “motor drive circuit”, the air conditioner 60 corresponds to the “auxiliary machine”, and the air conditioner inverter 62 corresponds to the “auxiliary machine drive circuit”. The battery 50 corresponds to the “power storage device”, the system main relay 54 for connecting the battery 50 to the drive system power line 56 and releasing the connection corresponds to “connection release means”, and the battery 50 and the system The voltage waveform output circuit 90 connected between the main relay 54 and each of the inverters 41 and 42, the air conditioner inverter 62, and the system main relay 54 are determined by insulation determination using a signal from the voltage waveform output circuit 90. Insulation resistance of FIG. 3 for an electric system that is a circuit including part or all of motors MG1, MG2, air conditioner 60, and battery 50 depending on the state. The combination with the hybrid electronic control unit 70 that executes the lowering detection processing routine corresponds to “insulation resistance lowering detection means”, and when the abnormality detection flag Fdet is 1 and there is an uncompleted area for specifying the current leakage portion. The motor area specifying process 5, the air conditioner area specifying process in FIG. 6, and the battery area specifying process in FIG. 7 are executed. The hybrid electronic control unit 70 for executing the insulation resistance lowering portion identification processing routine of FIG. 4, which executes the identification processing for the area that caused the unidentification when the stop is instructed, and the inverter 41 , 42 is combined with the motor ECU 40 that performs switching control corresponds to “part specifying control means”. Further, the motor MG also corresponds to the “motor”, and the inverter 142 also corresponds to the “motor drive circuit”.

  Here, the “motor” is not limited to the motor MG2 or the motor MG configured as a synchronous generator motor, and any type of motor can be used as long as it can output traveling power, such as an induction motor. It does not matter. The “motor drive circuit” is not limited to the inverter 42 and the inverter 142, and any circuit that drives the motor may be used. The “auxiliary machine” is not limited to the air conditioner 60, and any auxiliary machine such as another auxiliary machine motor may be used. The “auxiliary drive circuit” is not limited to the air conditioner inverter 62, and may be any device as long as it can drive an auxiliary machine, such as an auxiliary machine motor. The “power storage device” is not limited to the battery 50 configured as a lithium ion secondary battery, and may be any type of power storage device such as a nickel hydride secondary battery, a nickel cadmium secondary battery, or a lead storage battery. It doesn't matter. The “connection release means” is not limited to the system main relay 54, and any connection means can be used as long as it can connect and disconnect the power storage device and the drive system. The “insulation resistance drop detection means” is not limited to the combination of the voltage waveform output circuit 90 and the hybrid electronic control unit 70, but is a single circuit or a combination of a circuit and a plurality of electronic control units. For a circuit including a part or all of the electric motor, the auxiliary machine, and the power storage device according to each state of the electric motor driving circuit, the auxiliary driving circuit, and the connection release means, the insulation resistance of the circuit is reduced. Any device can be used as long as it can be detected. As the “part specifying control means”, the insulation resistance lowering part specifying process routine of FIG. 4 is executed with the execution of the motor area specifying process of FIG. 5, the air conditioner area specifying process of FIG. 6, and the battery area specifying process of FIG. The combination of the hybrid electronic control unit 70 and the motor ECU 40 is not limited to a combination of a single electronic control unit or a combination of three or more electronic control units. After the decrease in insulation resistance is detected, the drive circuit for the motor is specified so that it is specified which portion of the plurality of portions including the motor, the auxiliary device, and the power storage device has the decrease in the insulation resistance of the circuit. The first specific control for controlling the auxiliary device drive circuit and the connection release means is executed, and the insulation resistance of the circuit is also reduced by the execution of the first specific control. When the location cannot be specified, the location where the decrease in the insulation resistance of the circuit relative to the location that caused the unspecified status is specified after the next system startup. As long as the second specific control for controlling the electric motor drive circuit, the auxiliary drive circuit, and the connection release means is executed, any method may be used.

  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 ECU, 26 crankshaft, 30 planetary gear, 32 drive shaft, 34 differential gear, 36a, 36b drive wheel, 40 motor electronic control unit (motor ECU), 41, 42, 142 inverter, 50 battery, 52 battery electronic control unit (battery ECU), 54 system main relay, 56 drive power line, 58 smoothing capacitor, 60 electric compressor (air conditioner), 62 air conditioner inverter, 70 hybrid electronic control unit, 72 CPU 74 ROM, 76 RAM, 78 Flash memory, 80 Ignition switch, 82 Shift position sensor, 84 Accel pedal position sensor, 86 Brake pedal Position sensor, 88 vehicle speed sensor, 89 warning light, 90 voltage waveform output circuit, 92 oscillator, 94 detection resistor, 95 capacitor, 96 low-pass filter, 120 electric vehicle, MG1, MG2, MG motor.

Claims (4)

An electric motor capable of outputting driving power, an electric motor drive circuit for driving the electric motor, an auxiliary machine, an auxiliary machine drive circuit for driving the auxiliary machine, the electric motor drive circuit, and the auxiliary machine drive An electric vehicle comprising: a power storage device that supplies power to a drive system to which a circuit is connected; and connection release means for connecting and releasing the connection between the power storage device and the drive system,
Insulation resistance of the circuit with respect to a circuit including a part or all of the electric motor, the auxiliary machine, and the power storage device according to each state of the electric motor driving circuit, the auxiliary driving circuit, and the connection release means Insulation resistance decrease detection means for detecting a decrease in
A portion where a decrease in the insulation resistance of the circuit occurs among a plurality of portions including the electric motor, the auxiliary device, and the power storage device after a decrease in the insulation resistance of the circuit is detected by the insulation resistance decrease detecting means. The first specific control for controlling the motor drive circuit, the auxiliary drive circuit, and the connection release means is executed so that it is specified, and the circuit is also executed by executing the first specific control. When the part where the insulation resistance declined cannot be specified When the part cannot be specified, the insulation resistance of the circuit has dropped with respect to the part causing the unspecified after the system was started next time Part specifying control means for executing second specifying control for controlling the electric motor drive circuit, the accessory drive circuit, and the connection release means so that the part is specified;
An electric vehicle comprising: The electric vehicle according to claim 1,
In the first specific control, control is performed so as to determine whether or not each of the plurality of parts is a part where a decrease in the insulation resistance of the circuit occurs.
The time when the part cannot be specified includes when it is determined that the insulation resistance of the circuit has been lowered for two or more parts of the plurality of parts by executing the first specific control,
In the second specific control, it is determined whether or not each of the two or more portions as the portion causing the unspecified state is a portion where a decrease in the insulation resistance of the circuit has occurred. Is to control,
Electric vehicle. The electric vehicle according to claim 2,
In the first specific control, each of the parts excluding the non-energized part that is not energized when the insulation resistance reduction detecting unit detects a reduction in the insulation resistance of the circuit from the plurality of parts. It is controlled so as to determine whether or not the insulation resistance of the circuit is a part.
Electric vehicle. An electric vehicle according to any one of claims 1 to 3,
The first specific control and the second specific control include at least one of energization and deenergization of the electric motor, energization and deenergization of the auxiliary machine, and connection and release of connection of the power storage device to the drive system. Control is performed so that any one of the portions where the insulation resistance of the circuit is generated is specified.
Electric vehicle.

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