JP2009261133A - Electric vehicle, insulation resistance deterioration detecting method and computer-readable recording medium recording program for making computer execute the insulation resistance deterioration detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To specify an insulation resistance deterioration portion, in a vehicle when a fault current detector installed on a charging cable operates, at charging a storage device from a power supply outside of a vehicle. <P>SOLUTION: When a fault current is detected by the fault current detector 334 installed on the charging cable in a charging mode, information showing fault current detection is transmitted to an ECU220 of the vehicle, and a charging failure stop flag is stored in a storage part 230. In a running mode, where a connector 310 is removed from a charging inlet 210, by having the ECU220 operate a DFR202 to connect/disconnect an AC port 200 to/from an electrical system, the presence/absence of insulation resistance deterioration in the AC port 200 is determined, using an insulation resistance deterioration detector. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for detecting a decrease in insulation resistance in an electric vehicle that can receive power from a power supply external to the vehicle via a charging cable and charge a power storage device that stores the power for driving the vehicle from the power supply.

  Japanese Patent No. 3915219 (Patent Document 1) discloses a technique for preventing electric leakage when charging a battery of an electric vehicle using a power source outside the vehicle. In the charging device disclosed in this publication, when charging the battery, the voltage of the charging circuit is detected when the leakage circuit is forcibly short-circuited by closing the leakage test relay prior to the closing operation of the charging relay. The If it is determined that the detected voltage is not zero and the earth leakage relay is not operating, it is determined that the earth leakage relay is abnormal, and the closing operation of the charging relay is prohibited.

According to this charging device, the operation of the earth leakage breaker provided between the external power source and the vehicle is confirmed prior to charging, and the connection between the external power source and the vehicle is performed only when the earth leakage breaker operates normally. By doing so, the battery can be charged smoothly (see Patent Document 1).
Japanese Patent No. 3915219 JP 2003-219551 A JP 2007-157631 A

  The charging device described in the above publication is useful in that it can be confirmed whether the earth leakage breaker operates normally prior to charging. However, in this charging apparatus, the earth leakage breaker operates during charging and leakage is detected. In such a case, it is not assumed that the current leakage site will be specifically identified, and it is necessary to separately investigate the current leakage site.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electric vehicle capable of specifying an insulation resistance lowering portion when a leakage detector is operated when a power storage device is charged from a power supply outside the vehicle.

  Another object of the present invention is to execute an insulation resistance lowering detection method capable of specifying an insulation resistance lowering part and a method of detecting the same in a computer when an electric leakage detector is operated when the power storage device is charged from a power supply outside the vehicle. A computer-readable recording medium in which a program for causing the program to be recorded is recorded.

  According to the present invention, the electric vehicle is an electric vehicle that can receive electric power from a power supply external to the vehicle via a charging cable, and can charge the power storage device that stores the electric power for traveling the vehicle from the power supply external to the vehicle. And a storage unit and an insulation resistance drop detecting device. The charging port receives power supplied from the charging cable in a charging mode in which charging from a power source outside the vehicle is performed. The storage unit receives information indicating leakage detection from the leakage detector and stores it when leakage is detected by the leakage detector provided on the charging cable in the charging mode. The insulation resistance reduction detection device is configured to be able to specify a reduction in insulation resistance of a charging port or other predetermined part in a travel mode in which the electric vehicle can travel when information indicating leakage detection is stored in the storage unit.

  Preferably, the insulation resistance lowering detection device applies a voltage to the electrical system including the charging port and other predetermined parts, and the insulation resistance lowering part based on a change in voltage when each of the charging port and other predetermined parts is electrically disconnected. Is identified.

  More preferably, the electric vehicle further includes a relay capable of electrically connecting / disconnecting the charging port to / from the electric system. The insulation resistance lowering detection device determines whether or not there is a decrease in insulation resistance at the charging port by operating the relay in the traveling mode.

  More preferably, the insulation resistance lowering detection device determines that the insulation resistance lowering part is outside the vehicle when the voltage drop is not detected when the relay is connected. In addition, the insulation resistance decrease detection device detects that the voltage drop is detected when the relay is connected, and the voltage drop is detected when the relay is disconnected. Judged to be a port. In addition, when the voltage drop is detected regardless of the operation of the relay, the insulation resistance drop detection device determines that the insulation resistance drop part is a part other than the charging port in the vehicle.

  Preferably, the insulation resistance reduction detecting device determines whether or not insulation resistance is reduced in the charging port by operating a relay when the speed of the electric vehicle is equal to or higher than a predetermined value.

  Preferably, the insulation resistance lowering detection device determines whether or not there is a decrease in insulation resistance in the charging port by operating the relay when the lid of the charging port to which the charging cable is connected is closed.

  Further, according to the present invention, the insulation resistance decrease detection method is provided in an electric vehicle that can receive electric power from a power supply external to the vehicle via a charging cable and charge the power storage device that stores electric power for vehicle travel from the power supply external to the vehicle. This is a method for detecting a decrease in insulation resistance. The electric vehicle includes a charging port that receives electric power supplied from a charging cable in a charging mode in which charging from a power source outside the vehicle is performed. And the insulation resistance fall detection method shows the step which receives and memorize | stores the information which shows leakage detection from a leakage detector, and when leakage is detected by the leakage detector provided in the charge cable at the time of charge mode, and leakage detection A step of specifying a decrease in insulation resistance of the charging port and other predetermined parts when the information is stored in a travel mode in which the electric vehicle can travel.

  Preferably, in the step of identifying a decrease in insulation resistance, a voltage is applied to the electrical system including the charging port and other predetermined parts, and insulation is performed based on a change in voltage when each of the charging port and other predetermined parts is electrically disconnected. A resistance reduction site is identified.

  More preferably, the electric vehicle further includes a relay capable of electrically connecting / disconnecting the charging port to / from the electric system. Then, in the step of specifying a decrease in insulation resistance, the presence or absence of a decrease in insulation resistance at the charging port is determined by operating the relay in the traveling mode.

  More preferably, the step of identifying the decrease in insulation resistance includes the sub-step of determining that the insulation resistance decrease portion is outside the vehicle when the voltage decrease is not detected when the relay is in the connected state, and the relay in the connected state. When the voltage drop is detected, and when the return of the voltage is detected when the relay is disconnected, the substep for determining that the insulation resistance lowering part is the charging port and the operation of the relay Regardless of whether the voltage drop is detected, the sub-step of determining that the insulation resistance lowering portion is a portion other than the charging port in the vehicle is included.

  Preferably, the insulation resistance reduction detecting method further includes a step of determining whether or not the speed of the electric vehicle is equal to or higher than a predetermined value. And when it determines with the speed of an electric vehicle being more than predetermined value, in the step which specifies the fall of insulation resistance, the presence or absence of the insulation resistance fall in a charge port is determined by operating a relay.

  Preferably, the insulation resistance decrease detection method further includes a step of determining whether or not the charging port lid to which the charging cable is connected is closed. When it is determined that the lid of the charging port is in the closed state, in the step of specifying a decrease in insulation resistance, the presence or absence of a decrease in insulation resistance at the charging port is determined by operating the relay.

  According to the invention, the recording medium is a computer-readable recording medium, and records a program for causing the computer to execute any one of the above-described insulation resistance decrease detection methods.

  In the present invention, when leakage is detected by a leakage detector provided on the charging cable in the charging mode, information indicating leakage detection is transmitted to the vehicle and stored in the vehicle. And based on memorize | storing the information which shows leakage detection, the fall of the insulation resistance of a charge port other predetermined part is specified at the time of the driving | running | working mode which an electric vehicle can drive | work.

  Therefore, according to the present invention, it is possible to specify the insulation resistance lowering portion when the leakage detector operates when the power storage device is charged from the power supply outside the vehicle.

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

  FIG. 1 is a functional block diagram of an electric system mounted on an electric vehicle according to an embodiment of the present invention. Referring to FIG. 1, electrical system 10 includes a first power storage device 110, a first SMR (System Main Relay) 120, a first converter 130, a second power storage device 112, a second SMR 122, and a second converter 132. A first inverter 140, a second inverter 142, a third inverter 144, a first MG (Motor Generator) 150, a second MG 152, and a rear MG 154. The electric system 10 further includes an air conditioner inverter 160, an air conditioner compressor 170, a DC / DC converter 180, and an insulation resistance lowering detector 190. Furthermore, the electric system 10 further includes an AC port 200, a charging inlet 210, an ECU (Electronic Control Unit) 220, and a storage unit 230.

  First power storage device 110 is a rechargeable DC power source, and is composed of, for example, a secondary battery such as nickel metal hydride or lithium ion. The voltage of first power storage device 110 is, for example, about 200V. As described later, first power storage device 110 stores power supplied from a power source outside the vehicle, in addition to power generated by first MG 150, second MG 152, and rear MG 154.

  First SMR 120 is provided between first power storage device 110 and first converter 130. First SMR 120 is turned on / off based on a command from ECU 220. First converter 130 is a DC chopper type booster composed of a reactor (not shown) connected to positive line PL1 and upper and lower arms (not shown) connected in series between main positive line MPL and main negative line MNL. It consists of a circuit. First converter 130 boosts the voltage of main positive bus MPL to the voltage of positive line PL1 or more based on a command from ECU 220.

  Second power storage device 112, second SMR 122, and second converter 132 are configured similarly to first power storage device 110, first SMR 120, and first converter 130, respectively. First converter 130 and second converter 132 are connected in parallel to main positive bus MPL and main negative bus MNL. Note that a large-capacity capacitor can also be employed as the first power storage device 110 and the second power storage device 112.

  First inverter 140, second inverter 142, and third inverter 144 are provided corresponding to first MG 150, second MG 152, and rear MG 154, respectively. Each inverter is formed of a bridge circuit including switching elements for three phases, and is connected in parallel to main positive bus MPL and main negative bus MNL.

  First MG 150, second MG 152, and rear MG 154 are three-phase AC motors, for example, three-phase AC synchronous motor generators. That is, each of first MG 150, second MG 152, and rear MG 154 can generate a driving force by receiving AC power supplied from a corresponding inverter, and can generate regenerative power by receiving a rotating force on a rotating shaft.

  When the electric vehicle is a hybrid vehicle, for example, the first MG 150 is connected to an engine (not shown), the first MG 150 is caused to function as a generator that generates electric power using the driving force generated by the engine, and the engine is started. You may make it function as a possible electric motor. Second MG 152 and rear MG 154 are connected to front wheels and rear wheels (not shown), respectively, and second MG 152 and rear MG 154 function as electric motors for driving the front wheels and rear wheels, respectively. You may make it function as a generator which each receives a rotational force and generates electric power.

  The power line ACL1 is connected to the neutral point N1 of the first MG 150, and the power line ACL2 is connected to the neutral point N2 of the second MG 152. AC port 200 is disposed between power lines ACL1 and ACL2 and charging inlet 210. The AC port 200 connects / disconnects the charging inlet 210 to / from the electrical system 10, detects the voltage and current of power input from the charging inlet 210, filters noise generated in the power lines ACL1 and ACL2 during charging, and the like. . The configuration of the AC port 200 will be described in detail later.

  Charging inlet 210 is a power interface for receiving power from a power source outside the vehicle. When charging first power storage device 110 and second power storage device 112 from a power source outside the vehicle, charging inlet 210 is connected to a connector of a charging cable that transmits power from the power source outside the vehicle.

  The air conditioner inverter 160 is connected to a positive line PL1 and a negative line NL1 disposed between the first SMR 120 and the first converter 130, and is configured to drive the air conditioner compressor 170. The air conditioner compressor 170 is a compressor for an electric air conditioner. DC / DC converter 180 is also connected to positive electrode line PL1 and negative electrode line NL1, and steps down power supplied from positive electrode line PL1 to an auxiliary machine voltage level and outputs it to an auxiliary battery (not shown) and each auxiliary machine.

  The insulation resistance lowering detector 190 is a device for specifying and detecting an area where the insulation resistance of the electrical system 10 is lowered. That is, the electric system 10 is divided into a power source area 12, an air conditioner area 14, a transaxle ASSY area 16, a rear motor area 18, and a high voltage DC area 20. As will be described later, the insulation resistance lowering detector 190 applies a voltage composed of a square wave having a predetermined frequency to the power line to which the negative electrode of the first power storage device 110 is connected, and the voltage changes in accordance with the decrease in the insulation resistance. V is generated and output to ECU 220.

  When a decrease in the insulation resistance of the electrical system 10 is detected based on the voltage V from the insulation resistance decrease detector 190, if the insulation resistance is recovered by shutting off the gate of the air conditioner inverter 160, the air conditioner area 14 can be specified as the insulation resistance lowering portion. Similarly, when the insulation resistance is recovered due to the gate interruption of the first inverter 140 and the second inverter 142, the transaxle ASSY area 16 can be specified as the insulation resistance lowering portion, and the gate of the third inverter 144 can be specified. When the insulation resistance is recovered as a result of the interruption, the rear motor area 18 can be specified as the insulation resistance lowering portion. In addition, when a decrease in insulation resistance is not detected in each of the air conditioner area 14, the transaxle assembly area 16, and the rear motor area 18, if the insulation resistance is recovered as the first SMR 120 is turned off, the high voltage direct current The area 20 can be specified as the insulation resistance lowering portion, and when the insulation resistance does not recover as the first SMR 120 is turned off, the power source area 12 can be specified as the insulation resistance lowering portion.

  In addition, as described above, the electric system 10 includes the AC port 200 that receives power from a power source outside the vehicle. As described later, the electric system 10 is in a traveling mode in which the charging cable is not connected to the charging inlet 210. By operating a relay included in the AC port 200, a decrease in insulation resistance of the AC port 200 can be detected using the insulation resistance decrease detector 190. A method for detecting a decrease in insulation resistance of the AC port 200 will be described later.

  The ECU 220 operates the first SMR 120, the second SMR 122, the first converter 130, the second converter 132, the first inverter 140, the second inverter 142, the third inverter 144, the air conditioner inverter 160, the DC / DC converter 180, and the AC port 200. A signal for controlling is generated. In addition, ECU 220 identifies an insulation resistance lowering portion in electric system 10 based on voltage V received from insulation resistance lowering detector 190 by a method described later.

  The storage unit 230 includes a nonvolatile memory. Storage unit 230 is connected to a leakage detector (described later) provided on a charging cable connected to charging inlet 210 in a charging mode in which first power storage device 110 and second power storage device 112 are charged from a power supply external to the vehicle. When leakage is detected, information indicating leakage detection notified from the leakage detector to ECU 220 is received from ECU 220 and stored.

  FIG. 2 is a schematic configuration diagram of a portion related to the charging mechanism of the electrical system 10 shown in FIG. Referring to FIG. 2, AC port 200 includes a DFR (Dead Front Relay) 202, an LC filter 204, a voltage sensor 206, and a current sensor 208.

  DFR 202 is arranged between neutral point N1 of first MG 150 and neutral point N2 of second MG 152 and LC filter 204, and is turned on / off based on signal DE from ECU 220. In the charging mode, DFR 202 is turned on, and LC filter 204 and charging inlet 210 are electrically connected to neutral points N1 and N2. On the other hand, in the travel mode in which the vehicle can travel, DFR 202 is turned off, and LC filter 204 and charge inlet 210 are electrically disconnected from neutral points N1 and N2.

  The LC filter 204 includes an X capacitor, a Y capacitor, and a common mode choke coil. When the first power storage device 110 and the second power storage device 112 are charged from the power source 402, the LC filter 204 uses, as will be described later, the first inverter 140 and the first power from the power source external to the vehicle that are given to the neutral points N1 and N2. Noise generated in the power lines ACL1 and ACL2 when voltage conversion is performed using the two inverters 142 is reduced.

  Voltage sensor 206 detects voltage VAC between power lines ACL1 and ACL2, and outputs the detected value to ECU 220. Current sensor 208 detects current IAC flowing through power line ACL1 and outputs the detected value to ECU 220. Note that the current sensor 208 may be provided in the power line ACL2 to detect the current flowing through the power line ACL2.

  On the other hand, the charging cable that connects the vehicle and the power supply 402 outside the vehicle includes a connector 310, a plug 320, and a CCID (Charging Circuit Interrupt Device) 330. CCID 330 includes a relay 332, a leakage detector 334, and a control pilot circuit 336.

  Connector 310 is configured to be connectable to charging inlet 210. The connector 310 is provided with a limit switch 312. When connector 310 is connected to charging inlet 210, limit switch 312 is activated, and cable connection signal PISW indicating that connector 310 is connected to charging inlet 210 is input to ECU 220.

  Plug 320 is connected to a power outlet 400 provided in a house, for example. AC power is supplied to the power outlet 400 from a power source 402 (for example, a system power source).

  Relay 332 is provided on a pair of power lines for supplying charging power from power supply 402 to the vehicle. Relay 332 is turned on / off by control pilot circuit 336. When the relay 332 is turned off, the electric path for supplying power from the power source 402 to the vehicle is interrupted, and when the relay 332 is turned on, power can be supplied from the power source 402 to the vehicle.

  Leakage detector 334 is provided on a pair of power lines for supplying charging power from power supply 402 to the vehicle. Leakage detector 334 detects the equilibrium state of currents flowing in opposite directions to the power line pair, and detects the occurrence of leakage when the equilibrium state breaks down. When the leakage detector 334 detects a leakage, the leakage detector 334 notifies the control pilot circuit 336 to that effect.

  Control pilot circuit 336 outputs pilot signal CPLT to vehicle ECU 220 via connector 310 and charging inlet 210. The pilot signal CPLT notifies the rated current from the control pilot circuit 336 to the ECU 220 of the vehicle, and instructs the ECU 220 to drive the relay 332 from the ECU 220 to the control pilot circuit 336 based on the potential of the pilot signal CPLT operated by the ECU 220. Signal. Control pilot circuit 336 turns relay 332 on / off based on a command from ECU 220 based on pilot signal CPLT.

  When the control pilot circuit 336 receives a notification of leakage detection from the leakage detector 334, the control pilot circuit 336 turns off the relay 332 and notifies the vehicle that the leakage detection is detected by the leakage detector 334 using the pilot signal CPLT. Output to ECU 220.

  ECU 220 receives the detected value of voltage VAC from voltage sensor 206, and receives the detected value of current IAC from current sensor 208. ECU 220 receives rated signal, voltage VAC and current IAC notified by pilot signal CPLT when receiving cable connection signal PISW from connector 310, that is, when connector 310 of the charging cable is connected to charging inlet 210. Based on the detected value, the first inverter 140 and the second inverter 142 are controlled to convert the AC power supplied from the power source 402 into a DC voltage.

  Further, when ECU 220 receives a notification of leakage detection by leakage detector 334 from control pilot circuit 336 by means of pilot signal CPLT, ECU 220 stores an abnormal charging stop flag indicating that charging has stopped abnormally due to leakage detection by leakage detector 334. 230. Then, when the vehicle is activated as the travel mode by the system activation operation by the user, ECU 220 specifies the insulation resistance lowering portion in electric system 10 when the abnormal charging stop flag is stored in storage unit 230.

  The vehicle speed sensor 232 detects the vehicle speed SV in the traveling mode, and outputs the detected value to the ECU 220. The open / close sensor 234 advances the open / close state of the lid of the charging inlet 210 and outputs the detection result to the ECU 220 as a lid signal LID. The use of the vehicle speed SV and the lid signal LID will be described in modified examples 1 and 2 described later.

  FIG. 3 is a diagram showing a configuration of the insulation resistance lowering detector 190 shown in FIG. Referring to FIG. 3, insulation resistance lowering detector 190 includes a square wave generator 191, a resistance element 192, a capacitor 193, a body ground 194, and a voltage sensor 195.

  Square wave generator 191 has one end connected to body ground 194 and the other end connected to resistance element 192. The resistance element 192 has one end connected to the square wave generator 191 and the other end connected to the capacitor 193. Capacitor 193 has one end connected to resistance element 192 and the other end connected to negative electrode line NL1.

  Square wave generator 191 generates a voltage composed of a square wave with a low voltage (for example, several V) and a low frequency (for example, several Hz), and outputs the generated voltage to resistance element 192. Voltage sensor 195 detects voltage V between resistance element 192 and capacitor 193, and outputs the detected voltage V to ECU 220 (not shown).

  FIG. 4 is a diagram for explaining the principle of insulation resistance detection by the insulation resistance lowering detector 190 shown in FIG. With reference to FIG. 4, the resistance component 30 indicates the insulation resistance of the electrical system 10, and the capacitive component 40 indicates the capacitance between the electrical system 10 and the body ground 194. The square wave generator 191 of the insulation resistance lowering detector 190 generates a voltage composed of a low-voltage and low-frequency square wave, and supplies the generated voltage to the electrical system 10 via the resistance element 192 and the capacitor 193. Here, when the resistance component 30 indicating the insulation resistance decreases, the impedance of the electrical system 10 decreases, so the voltage V between the resistance element 192 and the electrical system 10 decreases. Therefore, a decrease in insulation resistance can be detected based on this voltage V.

  FIG. 5 is a flowchart for illustrating a control structure in the charging mode by ECU 220 shown in FIGS. Note that the processing of this flowchart is executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 5, ECU 220 determines whether or not the operation mode of the vehicle is the charging mode (step S10). For example, when ECU 220 receives cable connection signal PISW from connector 310 and pilot signal CPLT from control pilot circuit 336, ECU 220 determines that the charging mode is set.

  If it is determined in step S10 that the charging mode is not set (NO in step S10), ECU 220 proceeds to step S60. On the other hand, when it is determined in step S10 that the charging mode is set (YES in step S10), ECU 220 actually executes charging control (step S20).

  Here, during the charging mode, leakage is monitored by leakage detector 334 of CCID 330. ECU 220 detects leakage by leakage detector 334 based on pilot signal CPLT from control pilot circuit 336 of CCID 330. It is determined whether or not (step S30).

  If it is determined that leakage is detected by leakage detector 334 (YES in step S30), ECU 220 executes a charge stop process (step S40). Specifically, ECU 220 stops charging control, turns off DFR 202, and instructs CCID 330 to turn off relay 332 by operating the potential of pilot signal CPLT to a predetermined potential.

  Thereafter, ECU 220 outputs a charging abnormality stop flag indicating that charging has stopped abnormally due to leakage detected by leakage detector 334 to storage unit 230, and stores the charging abnormality stop flag in storage unit 230 (step 230). S50).

  FIG. 6 is a flowchart for explaining a process for specifying the insulation resistance lowering portion by ECU 220 shown in FIGS. Note that the processing of this flowchart is also executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 6, ECU 220 determines whether or not the operation mode of the vehicle is the travel mode (step S100). For example, ECU 220 determines that the vehicle is in the traveling mode when the vehicle system is activated by the user using a start switch, an ignition key, or the like and neither cable connection signal PISW nor pilot signal CPLT is received.

  If it is determined in step S100 that the travel mode is not set (NO in step S100), ECU 220 proceeds to step S190. On the other hand, when it is determined in step S100 that the travel mode is set (YES in step S100), ECU 220 determines whether or not the abnormal charging stop flag is stored in storage unit 230 (step S110). If the abnormal charging stop flag is not stored in storage unit 230 (NO in step S110), ECU 220 proceeds to step S190.

  If it is determined in step S110 that the abnormal charging stop flag is stored in storage unit 230 (YES in step S110), ECU 220 outputs a signal DE for turning on DFR 202 to DFR 202 to turn on DFR 202 ( Step S120). As a result, the AC port 200 is electrically connected to the electrical system 10.

  Then, ECU 220 determines whether or not the peak value of voltage V from insulation resistance decrease detector 190 (hereinafter also referred to as “detected peak value”) has decreased (step S130). When the detected peak value does not decrease (NO in step S130), ECU 220 identifies the insulation resistance decreasing portion as the vehicle exterior (charging cable side) (step S180).

  On the other hand, when a decrease in the detected peak value is detected in step S130 (YES in step S130), a signal DE for turning off DFR 202 is output to DFR 202, and DFR 202 is turned off (step S140). As a result, the AC port 200 is electrically disconnected from the electrical system 10.

  After AC port 200 is electrically disconnected from electrical system 10, ECU 220 determines whether or not the detected peak value has decreased (step S150). Then, when the detected peak value is restored due to electrical disconnection of AC port 200 from electrical system 10 (YES in step S150), ECU 220 identifies the insulation resistance lowering portion as AC port 200 ( Step S160). On the other hand, if the detected peak value does not return even when AC port 200 is electrically disconnected from the electrical system (NO in step S150), ECU 220 determines that the insulation resistance lowering portion is other than AC port 200. By the method described above, it is specified which of the power source area 12, the air conditioner area 14, the transaxle ASSY area 16, the rear motor area 18 and the high voltage DC area 20 has a decrease in insulation resistance (step S170). ).

  As described above, when leakage is detected by the leakage detector 334 during the charging mode, information indicating leakage detection is notified to the ECU 220, and the ECU 220 stores the detected leakage in the storage unit 230 until the traveling mode is entered. To do. And ECU220 specifies the insulation resistance fall part of the electric system 10 containing the AC port 200 using the insulation resistance fall detector 190 at the time of driving | running | working mode from which the charging cable was removed from the charge inlet 210. FIG.

  If the insulation resistance lowering portion is identified as AC port 200, normal driving is performed because there is no obstacle to vehicle driving if DFR 202 is turned off. On the other hand, if it is determined in step S170 that the insulation resistance lowering part is other than the AC port 200, measures such as prohibiting the next system activation or limiting the travel time are taken.

  Next, a method for converting AC power supplied from the power supply 402 outside the vehicle into DC power that can charge the power storage device will be described.

  FIG. 7 shows a zero-phase equivalent circuit of first and second inverters 140 and 142 and first and second MGs 150 and 152 shown in FIG. Each of first inverter 140 and second inverter 142 is composed of a three-phase bridge circuit, and there are eight patterns of ON / OFF combinations of six switching elements in each inverter. Two of the eight switching patterns have zero interphase voltage, and such a voltage state is called a zero voltage vector. For the zero voltage vector, the three switching elements of the upper arm can be regarded as the same switching state (all on or off), and the three switching elements of the lower arm can also be regarded as the same switching state.

  When charging first power storage device 110 and second power storage device 112 from power supply 402 outside the vehicle, zero-phase voltage command values are generated based on the detected values of voltage VAC and current IAC, and first inverter 140 and second inverter The zero voltage vector of 142 is controlled. Accordingly, in FIG. 7, the three switching elements of the upper arm of the first inverter 140 are collectively shown as an upper arm 140A, and the three switching elements of the lower arm of the first inverter 140 are collectively shown as a lower arm 140B. ing. Similarly, the three switching elements of the upper arm of the second inverter 142 are collectively shown as an upper arm 142A, and the three switching elements of the lower arm of the second inverter 142 are collectively shown as a lower arm 142B.

  As shown in FIG. 7, this zero-phase equivalent circuit includes a single-phase PWM converter that receives a single-phase AC power supplied from the power source 402 to the neutral point N 1 of the first MG 150 and the neutral point N 2 of the second MG 152. Can be seen. Therefore, switching control is performed so that the first inverter 140 and the second inverter 142 change the zero voltage vector based on the zero phase voltage command value, and the first inverter 140 and the second inverter 142 operate as an arm of the single phase PWM converter. By doing so, AC power supplied from the power source 402 can be converted to DC power and supplied to the main positive bus MPL and the main negative bus MNL. Then, the first power storage device 110 can be charged via the first converter 130 and the second power storage device 112 can be charged via the second converter 132.

  As described above, in this embodiment, when leakage is detected by leakage detector 334 provided in the charging cable in the charging mode, information indicating leakage detection is transmitted to ECU 220 of the vehicle and stored in storage unit 230. Remembered. And based on memorize | storing the information which shows leakage detection, the fall of the insulation resistance of the electric system 10 is specified at the time of driving | running | working mode. Therefore, according to this embodiment, it is possible to specify the insulation resistance lowering portion of the electric system 10 including the AC port 200.

[Modification 1]
FIG. 8 is a flowchart for explaining a process for specifying an insulation resistance lowering portion by ECU 220 in the first modification. The processing of this flowchart is also executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 8, this flowchart further includes step S112 in the flowchart shown in FIG.

  That is, when it is determined in step S110 that the abnormal charging stop flag is stored in storage unit 230 (YES in step S110), ECU 220 determines that vehicle speed SV detected by vehicle speed sensor 232 is greater than a predetermined threshold value. It is determined whether it is also high (step S112). This threshold value is a threshold value for determining whether or not the vehicle is traveling.

  If it is determined that vehicle speed SV is higher than the threshold value (YES in step S112), ECU 220 proceeds to step S120 and DFR 202 is turned on. On the other hand, when it is determined that vehicle speed SV is equal to or less than the threshold value (NO in step S112), ECU 220 does not turn on DFR 202 and proceeds to step S190.

  As described above, in the first modification, only when it is determined that the vehicle is traveling, the DFR 202 is turned on and the insulation resistance lowering portion is specified. In other words, when the vehicle is stopped, the DFR 202 is not turned on and the charging inlet 210 is not electrically connected to the electric system. Therefore, according to the first modification, it is possible to prevent voltage from being generated in the charging inlet 210 when the vehicle is stopped in the traveling mode.

[Modification 2]
FIG. 9 is a flowchart for explaining a process for specifying an insulation resistance lowering portion by ECU 220 in the second modification. The processing of this flowchart is also executed at regular time intervals or whenever a predetermined condition is satisfied. Referring to FIG. 9, this flowchart further includes step S114 in the flowchart shown in FIG.

  In other words, when it is determined in step S110 that the abnormal charging stop flag is stored in storage unit 230 (YES in step S110), ECU 220 is connected to charging inlet 210 based on lid signal LID from open / close sensor 234. It is determined whether or not the provided charging lid is in a closed state (step S114).

  If it is determined that the charging lid is in the closed state (YES in step S114), ECU 220 proceeds to step S120 and DFR 202 is turned on. On the other hand, when it is determined that the charging lid is in the open state (NO in step S114), ECU 220 does not turn on DFR 202 and proceeds to step S190.

  Thus, in the second modification, only when it is determined that the charging lid is in the closed state in the traveling mode, the DFR 202 is turned on, and the insulation resistance lowering portion is specified. Therefore, according to the second modification, it is possible to prevent the charging inlet 210 from being exposed to the outside in a state where a voltage is generated.

  In the above-described embodiment, power from power supply 402 is applied to neutral points N1 and N2, and first and second inverters 140 and 142 and first and second MGs 150 and 152 are operated as a single-phase PWM converter. Thus, the first power storage device 110 and the second power storage device 112 are charged. However, a dedicated voltage converter and rectifier for charging the first power storage device 110 and / or the second power storage device 112 from the power source 402 are provided. You may separately connect to the 1st electrical storage apparatus 110 and / or the 2nd electrical storage apparatus 112 in parallel.

  In the above description, the air conditioner inverter 160, the DC / DC converter 180, and the insulation resistance drop detector 190 are connected to the power supply system including the first power storage device 110, the first SMR 120, and the first converter 130. Alternatively, the second power storage device 112, the second SMR 122, and the second converter 132 may be connected to the power system side.

  In the above description, the second power storage device 112, the second SMR 122, and the second converter 132 are provided in addition to the first power storage device 110, the first SMR 120, and the first converter 130. The present invention is also applicable to an electric vehicle that does not include the device 112, the second SMR 122, and the second converter 132.

  The present invention can also be applied to an electric vehicle that travels only with electric power from the power storage device, a hybrid vehicle that further includes an engine as a power source, and a fuel cell vehicle that further includes a fuel cell in addition to the power storage device as a power source. It is.

  In the above, the control in the ECU 220 is actually performed by a CPU (Central Processing Unit), and the CPU reads a program including each step of the above-described flowchart from a ROM (Read Only Memory) and reads the program. To execute the process according to the flowchart described above. Accordingly, the ROM corresponds to a computer (CPU) readable recording medium that records a program including the steps of the above-described flowchart.

  In the above, insulation resistance drop detector 190 and ECU 220 form one embodiment of the “insulation resistance drop detection device” in the present invention, and AC port 200 serves as one embodiment of “charging port” in the present invention. Correspond.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

It is a functional block diagram of the electric system mounted in the electric vehicle by embodiment of this invention. It is a schematic block diagram of the part regarding the charge mechanism of the electric system shown in FIG. It is the figure which showed the structure of the insulation resistance fall detector shown in FIG. It is a figure for demonstrating the detection principle of the insulation resistance by the insulation resistance fall detector shown in FIG. It is a flowchart for demonstrating the control structure at the time of charge mode by ECU. It is a flowchart for demonstrating the process for specifying an insulation resistance fall part by ECU. It is the figure which showed the zero-phase equivalent circuit of the 1st and 2nd inverter and 1st and 2nd MG which are shown in FIG. 10 is a flowchart for explaining a process for specifying an insulation resistance lowering portion by an ECU according to Modification 1; 12 is a flowchart for explaining processing for specifying a portion where insulation resistance is reduced by an ECU according to Modification 2;

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Electric vehicle, 12 Power supply area, 14 Air-conditioner area, 16 Transaxle ASSY area, 18 Rear motor area, 20 High voltage direct current area, 30 Resistance component, 40 Capacity component, 110, 112 Power storage device, 120, 122 SMR, 130, 132 Converter, 140, 142, 144 Inverter, 140A, 142A Upper arm, 140B, 142B Lower arm, 150, 152 MG, 154 Rear MG, 160 Air conditioner inverter, 170 Air conditioner compressor, 180 DC / DC converter, 190 Insulation resistance drop detection 191 square wave generator, 192 resistor element, 193 capacitor, 194 body ground, 195 voltage sensor, 200 AC port, 202 DFR, 204 LC filter, 206 voltage sensor, 2 08 Current sensor, 210 Charging inlet, 220 ECU, 230 Storage unit, 232 Vehicle speed sensor, 234 Open / close sensor, 310 connector, 312 Limit switch, 320 plug, 330 CCID, 332 relay, 334 Leakage detector, 336 Control pilot circuit, 400 Power outlet, 402 power supply, 500 system to be detected, PL1, PL2 positive line, NL negative line, MPL main positive line, MNL main negative line, N1, N2 neutral point, ACL1, ACL2 power line.

Claims (13)

An electric vehicle that receives electric power from a power source outside the vehicle via a charging cable and can charge the power storage device that stores electric power for vehicle travel from the power source,
A charging port for receiving power supplied from the charging cable in a charging mode in which charging from the power source is performed;
A storage unit that receives and stores information indicating leakage detection from the leakage detector when leakage is detected by the leakage detector provided in the charging cable during the charging mode;
When the information is stored in the storage unit, an electric resistance provided with an insulation resistance decrease detecting device configured to be able to specify a decrease in insulation resistance of the charging port and other predetermined parts in a travel mode in which the electric vehicle can travel. vehicle.   The insulation resistance lowering detection device applies a voltage to the electrical system including the charging port and the predetermined part, and insulates based on a change in the voltage when each of the charging port and the predetermined part is electrically disconnected. The electric vehicle according to claim 1, wherein a resistance lowering portion is specified. A relay capable of electrically connecting / disconnecting the charging port to / from the electrical system;
The electric vehicle according to claim 2, wherein the insulation resistance lowering detection device determines whether or not there is a decrease in insulation resistance in the charging port by operating the relay in the travel mode. The insulation resistance drop detecting device is
When the voltage drop is not detected when the relay is in the connected state, the insulation resistance lowering portion is determined to be outside the vehicle;
When the voltage drop is detected when the relay is in the connected state, and when the voltage return is detected when the relay is in the disconnected state, the insulation resistance lowering portion is the charging port. And
The electric vehicle according to claim 3, wherein when the voltage drop is detected regardless of the operation of the relay, the insulation resistance reduction portion is determined to be a portion other than the charging port in the vehicle.   The said insulation resistance fall detection apparatus determines the presence or absence of the insulation resistance fall in the said charge port by operating the said relay, when the speed of the said electric vehicle is more than predetermined value. Electric vehicle.   The said insulation resistance fall detection apparatus determines the presence or absence of insulation resistance fall in the said charge port by operating the said relay, when the cover of the charge port to which the said charge cable is connected is a closed state. Item 5. The electric vehicle according to Item 4. A method for detecting a decrease in insulation resistance in an electric vehicle that can be charged from a power storage device that receives electric power from a power source outside the vehicle via a charging cable and stores electric power for traveling the vehicle,
The electric vehicle includes a charging port that receives power supplied from the charging cable in a charging mode in which charging from the power source is performed,
The insulation resistance drop detection method is:
When leakage is detected by a leakage detector provided on the charging cable during the charging mode, receiving information indicating leakage detection from the leakage detector and storing it;
And a step of specifying a decrease in insulation resistance of the charging port and other predetermined parts in a travel mode in which the electric vehicle can travel when the information is stored.   In the step of specifying a decrease in insulation resistance, a voltage is applied to the electrical system including the charging port and the predetermined part, and the voltage changes when the charging port and the predetermined part are electrically disconnected. The insulation resistance reduction detection method according to claim 7, wherein an insulation resistance reduction site is identified based on the basis. The electric vehicle further includes a relay capable of electrically connecting / disconnecting the charging port to / from the electric system,
The method for detecting a decrease in insulation resistance according to claim 8, wherein in the step of identifying a decrease in insulation resistance, the presence or absence of a decrease in insulation resistance at the charging port is determined by operating the relay in the travel mode. The step of identifying a decrease in insulation resistance comprises:
When the voltage drop is not detected when the relay is in the connected state, the sub-step of determining that the insulation resistance lowering part is outside the vehicle;
When the voltage drop is detected when the relay is in the connected state, and when the voltage return is detected when the relay is in the disconnected state, the insulation resistance lowering portion is the charging port. A sub-step for determining
10. The insulation according to claim 9, further comprising: a sub-step of determining that the insulation resistance lowering portion is a portion other than the charging port in the vehicle when the voltage drop is detected regardless of the operation of the relay. Resistance drop detection method. Determining whether the speed of the electric vehicle is equal to or higher than a predetermined value;
When it is determined that the speed of the electric vehicle is equal to or higher than a predetermined value, in the step of specifying a decrease in insulation resistance, the presence or absence of a decrease in insulation resistance in the charging port is determined by operating the relay. Item 11. The method for detecting a decrease in insulation resistance according to Item 9 or Item 10. Further comprising the step of determining whether the lid of the charging port to which the charging cable is connected is closed,
When it is determined that the lid of the charging port is in a closed state, in the step of specifying a decrease in insulation resistance, it is determined whether or not there is a decrease in insulation resistance in the charging port by operating the relay. The method for detecting a decrease in insulation resistance according to claim 9 or claim 10.   A computer-readable recording medium storing a program for causing a computer to execute the insulation resistance reduction detecting method according to any one of claims 7 to 12.

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