JP5421000B2 - Electric vehicle, welding determination device, and welding determination program - Google Patents

Description

  The present invention relates to an electric vehicle, a welding determination device, and a welding determination program, and more particularly to determination of welding of a relay of a charging device in an electric vehicle.

  In an electric vehicle having a traveling motor that is driven by electric power of the power storage device, there is a technique for charging the power storage device with an external power source outside the vehicle (see, for example, Patent Document 1).

  Patent Document 1 describes a system including an electric vehicle and a charging device that charges a power storage device of the electric vehicle with electric power from an AC power supply outside the vehicle. In this system, the charging device includes a relay that cuts off / connects a power feeding path from the AC power source to the power storage device, and a test circuit that determines welding of the relay. When an AC power source is connected to the charging device, the test circuit acquires a voltage value on the opposite side of the AC power source of the relay, and when the voltage value indicates an AC voltage (specifically, AC 100 V), Determined to be welded.

JP 2008-31380 A

  By the way, in an electric vehicle having a relay that opens and closes a power supply path from an external power source to the power storage device, in the configuration in which the voltage of the external power source is applied to the relay to determine welding of the relay, it is necessary to connect the external power source to the electric vehicle. Yes, for example, the welding of the relay cannot be determined while the vehicle is running.

  The present invention relates to an electric vehicle, a welding determination device, and a welding determination capable of determining welding of a relay that opens and closes a power supply path from an external power source to a power storage device without the need to apply the voltage of the external power source to the relay. Provide a program.

An electric vehicle according to the present invention includes a power storage device, an inverter that drives a rotating electric machine for traveling with the power of the power storage device, and an alternating current of the external power source to direct current to charge the power storage device with power of an external power source. A charging device for converting into current, the charging device including a pair of relays for opening and closing a power feeding path from the external power source to the power storage device so as not to interrupt a path between the power storage device and the inverter; during switching operation of the inverter, while controlling the respective relays in the open state, the detected voltage caused by the switching noise of the inverter in the external power supply side of each relay, each relay on the basis of the detection result And a welding determination device for determining whether or not at least one of them is welded.

The welding determination device according to the present invention includes an AC current of the external power source for charging the power storage device, an inverter that drives a rotating electric machine for traveling with the power of the power storage device, and an external power source. A charging device for converting to direct current, the charging device including a pair of relays for opening and closing a power feeding path from the external power source to the power storage device so as not to interrupt a path between the power storage device and the inverter; , a welding determination device for an electric vehicle having a, during a switching operation of the inverter, while controlling the respective relays in the open state, the voltage due to switching noise of the inverter in the external power supply side of each relay a voltage detecting means for detecting whether at least one of the detection results on the basis of the respective relay the voltage detecting means is welded And determining the welding judging means, characterized by having a.

The welding determination program according to the present invention includes an AC current of the external power supply for charging the power storage device, an inverter that drives a rotating electric machine for traveling with the power of the power storage device, and an electric power of an external power supply. A charging device for converting to direct current, the charging device including a pair of relays for opening and closing a power feeding path from the external power source to the power storage device so as not to interrupt a path between the power storage device and the inverter; , a welding determination program of an electric vehicle having a, in the computer, during a switching operation of the inverter, while controlling the respective relays in the open state, the switching noise of the inverter in the external power supply side of each relay a voltage detection procedure for detecting a voltage caused by, Sukunakutomoizu of each relay based on a detection result of said voltage detection procedure Or the other is characterized in that to execute a welding determination procedure for determining whether or not the welding.

  According to the present invention, it is possible to determine the welding of a relay that opens and closes a power supply path from an external power source to a power storage device without the need to apply the voltage of the external power source to the relay.

1 is a schematic configuration diagram showing a configuration of an electric vehicle according to an embodiment. It is a flowchart which shows an example of the welding determination process in embodiment. It is a block diagram showing a first specific example of an electric vehicle according to an embodiment. It is a wave form diagram which shows typically a potential when the relay of the positive electrode side is in a connection state. It is a wave form diagram which shows typically a potential when the relay of the negative electrode side is in a connection state. It is a block diagram which shows the 2nd specific example of the electric vehicle which concerns on embodiment. It is a sequence diagram which shows an example of operation | movement of the welding determination method different from embodiment. It is a sequence diagram which shows an example of operation | movement of the welding determination method of embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing a configuration of an electric vehicle 1 according to the present embodiment. The electric vehicle 1 is a vehicle that travels by driving a rotating electric machine for traveling with the electric power of the power storage device, and is configured such that the power storage device can be charged by an external power source outside the vehicle.

  In FIG. 1, electric vehicle 1 includes power storage device 10, inverter 20, rotating electrical machine 30, charging device 40, and control device 50.

  The power storage device 10 is a device that stores electric power for vehicle travel and is configured to be chargeable / dischargeable. The power storage device 10 is a secondary battery such as a nickel metal hydride battery or a lithium ion battery. However, the power storage device 10 may be other than a secondary battery such as a large capacity capacitor.

  The inverter 20 drives and controls the traveling rotary electric machine 30 with the electric power from the power storage device 10. Inverter 20 may charge power storage device 10 with electric power generated by rotating electrical machine 30. Specifically, inverter 20 includes a switching element, and performs power conversion between power storage device 10 and rotating electrical machine 30 by a switching operation of the switching element.

  The rotating electrical machine 30 is supplied with electric power from the inverter 20 and rotates a wheel (not shown). The rotating electrical machine 30 may operate as a generator during regenerative braking and supply generated power to the inverter 20.

  Charging device 40 is a device for charging power storage device 10 with electric power from external power supply 2 that is a power supply outside the vehicle, and includes at least a relay that opens and closes a power supply path from external power supply 2 to power storage device 10. This relay is provided so as not to interrupt the path between power storage device 10 and inverter 20. The external power source 2 is a commercial power source such as a household commercial power source (for example, single-phase AC 100 V).

  In the example of FIG. 1, the charging device 40 includes relays 41 and 42 that open and close a power supply path from the external power supply 2 to the power storage device 10, and a charging unit 43 that is the other component.

  Relay 41 is provided on power line L1 for connecting the positive electrode of power storage device 10 and charging unit 43, and relay 42 is provided on power line L2 for connecting the negative electrode of power storage device 10 and charging unit 43. It is done. Power line L1 is connected to a positive line PL that connects the positive electrode of power storage device 10 and inverter 20, and power line L2 is connected to a negative electrode line NL that connects the negative electrode of power storage device 10 and inverter 20.

  The charging unit 43 has, for example, a function of converting AC power of the external power source 2 into DC power, a function of boosting, and the like.

  The control device 50 controls the operation of the electric vehicle 1. In one embodiment, the control device 50 is realized by cooperation of hardware resources and software, and is, for example, an electronic control unit (ECU). Specifically, the function of the control device 50 is realized by reading a program recorded in a recording medium such as a ROM (Read Only Memory) into the main memory and executing it by a CPU (Central Processing Unit). . The program can be provided by being recorded on a computer-readable recording medium, or can be provided by communication as a data signal. However, the control device 50 may be realized only by hardware. The control device 50 may be physically realized by one device or may be realized by a plurality of devices.

  The control device 50 controls the rotating electrical machine 30 by controlling the switching operation of the inverter 20 during traveling of the vehicle.

  When charging the power storage device 10 with the external power source 2, the control device 50 controls the charging unit 43 while controlling the relays 41 and 42 to close the power storage device 10 with the power of the external power source 2. Charge.

  Further, the control device 50 has a function as a welding determination device that determines welding of the relay of the charging device 40. The relay welding determination will be described below.

  During the switching operation of the inverter 20 such as when the vehicle is running, switching noise (high frequency noise) is generated. For example, the potential of the high-voltage circuit (for example, the potential of the positive line PL or the negative line NL) with respect to the vehicle body ground such as the vehicle chassis or the vehicle body. ) Changes. At this time, if one or both of the relays 41 and 42 are in a closed state (connected state), switching noise propagates to the external power source 2 side of the relay, and the vehicle body ground of the power lines L1 and L2 on the external power source 2 side of the relay Variation in the potential with respect to.

  Therefore, when switching noise or potential fluctuation is observed on the external power supply 2 side of the relay despite the relays 41 and 42 being controlled to be in the open state, the relay 41 or 42 may be welded. It is considered that the nature is high.

  Therefore, in the present embodiment, the control device 50 detects the voltage on the external power supply 2 side of the relays 41 and 42 while controlling the relays 41 and 42 in the open state during the switching operation of the inverter 20, and detects the detection. The welding of the relay is determined based on the result. Specifically, the control device 50 determines that the relay is welded when a voltage equal to or higher than a predetermined threshold is detected. In other words, when the control device 50 controls the relays 41 and 42 to the open state during the switching operation of the inverter 20, when switching noise is detected on the external power supply 2 side of the relays 41 and 42. It is determined that the relay is welded. In short, in the present embodiment, the welding determination of the relay is performed using switching noise caused by the inverter 20.

  In one aspect, the control device 50 detects the voltage between the power lines L1 and L2 on the external power supply 2 side of the relays 41 and 42 while controlling the relays 41 and 42 to be in an open state, and based on the detection result. The presence or absence of welding of the relays 41 and 42 is determined. For example, when a voltage equal to or higher than a predetermined threshold is detected, it is determined that at least one of the relays 41 and 42 is welded.

  The control device 50 detects the voltage between the power line L1 on the external power supply 2 side of the relay 41 and the vehicle body ground (that is, the potential of the power line L1) while controlling at least the relay 41 in the open state, and the detection result Whether or not the relay 41 is welded may be determined based on the above. Further, the control device 50 detects the voltage between the power line L2 on the external power supply 2 side of the relay 42 and the vehicle body ground (that is, the potential of the power line L2) while controlling at least the relay 42 in the open state. Whether or not the relay 42 is welded may be determined based on the detection result.

  Moreover, in one aspect, the relays 41 and 42 are normally open types, and are closed by a connection command from the control device 50, and are opened when there is no connection command. In this case, the control device 50 detects the voltage on the external power supply 2 side of the relays 41 and 42 without issuing a connection command to the relays 41 and 42 during the switching operation of the inverter 20, and relays based on the detection result. Welding judgment is performed.

  Further, in one aspect, the voltage detection and welding determination described above are always performed during the switching operation of the inverter 20 such as when the vehicle is traveling. However, voltage detection and welding determination need not always be performed, but may be performed at appropriate timing.

  In FIG. 1, the control device 50 includes a voltage detection unit 51 and a welding determination unit 52 as functional blocks for welding determination.

  The voltage detector 51 detects the voltage on the external power supply 2 side of the relays 41 and 42 while controlling the relays 41 and 42 to be in an open state during the operation of the inverter 20. The voltage detector 51 acquires a voltage detected by, for example, a voltage sensor.

  The welding determination unit 52 determines welding of the relays 41 and 42 based on the detection result of the voltage detection unit 51.

  FIG. 2 is a flowchart showing an example of welding determination processing in the present embodiment. This welding determination process is repeatedly executed, for example, every predetermined time.

  In FIG. 2, the control device 50 determines whether or not the switching operation of the inverter 20 is being performed (S1).

  When it is determined that the switching operation is not being performed (S1: NO), the control device 50 ends the process.

  On the other hand, when it is determined that the switching operation is being performed (S1: YES), the control device 50 controls the relays 41 and 42 to be in the open state, and the power line L1 on the external power source 2 side of the relays 41 and 42. , L2 is detected (S2).

  Next, the control device 50 determines whether or not the voltage detected in step S2 is greater than or equal to a predetermined threshold (S3).

  When it is determined that the detected voltage is equal to or higher than the predetermined threshold (S3: YES), the control device 50 determines that the relays 41 and 42 are welded, and notifies the user to that effect (S4).

  On the other hand, when it is determined that the detected voltage is not equal to or higher than the predetermined threshold (S3: NO), the control device 50 determines that the relays 41 and 42 are not welded and ends the process.

  According to the present embodiment described above, the following effects (1) and (2) can be obtained.

  (1) In the present embodiment, the electric vehicle includes a power storage device, an inverter that drives a rotating electric machine for traveling with the power of the power storage device, and a charging device for charging the power storage device with power from an external power source. The charging device includes a relay that opens and closes a power feeding path from the external power source to the power storage device so as not to interrupt a path between the power storage device and the inverter. In the electric vehicle, the welding determination device detects the voltage on the external power supply side of the relay while controlling the relay in the open state during the switching operation of the inverter, and determines the welding of the relay based on the detection result. Therefore, according to the present embodiment, it is possible to determine the welding of the relay using switching noise, and it is possible to determine the welding of the relay without the need to apply the voltage of the external power source to the relay. . Thereby, for example, it becomes possible to determine welding of the relay while the vehicle is traveling.

  (2) As a welding determination method for a relay different from the present embodiment, a connection command is given to one of the two relays on the positive electrode side and the negative electrode side, and at this time, between the power lines on the external power supply side of the two relays A method of detecting the voltage and determining that the other relay is welded when a voltage equal to or higher than a predetermined threshold is detected is assumed. That is, a method of performing relay welding determination using the voltage of the power storage device is conceivable. However, with this method, when a connection command is given to one relay during the switching operation of the inverter, the potential on the external power supply side of the relay is affected by switching noise, and relay welding may be erroneously determined. There is sex. On the other hand, according to the present embodiment, it is possible to satisfactorily determine relay welding even during the switching operation of the inverter.

  In the example of FIG. 1, the two relays 41 and 42 on the positive electrode side and the negative electrode side are provided, but a configuration in which the relay is provided on only one side of the positive electrode side and the negative electrode side may be employed. Further, part or all of the charging unit 43 may be provided outside the vehicle. For example, the charging unit 43 may be configured by an on-vehicle charger and an on-vehicle charger.

  The welding determination device may cause the inverter to perform a switching operation in order to determine relay welding.

  Hereinafter, two specific examples of the electric vehicle 1 according to the present embodiment will be shown as more specific configuration examples. In the following specific example, the electric vehicle 1 is a hybrid vehicle having an internal combustion engine and a rotating electric machine as drive sources.

(First specific example)
FIG. 3 is a configuration diagram showing a first specific example of electrically powered vehicle 1 according to the present embodiment. Hereinafter, a first specific example of the electric vehicle 1 will be described with reference to FIG.

  In FIG. 3, an electric vehicle 1 includes a power storage device 110, system main relays (hereinafter referred to as “SMR”) 121, 122, 123, a smoothing capacitor C1, a boost converter 130, a smoothing capacitor C2, inverters 141, 142, a rotating electric machine. 151, 152, a charging device 160, a connector 170, and a control device 180.

  The power storage device 110 is a rechargeable power source that supplies DC power to a load. Positive electrode line PL1 is connected to the positive electrode of power storage device 110, and negative electrode line NL1 is connected to the negative electrode.

  SMRs 121, 122, and 123 open and close a power supply path from power storage device 110 to boost converter 130. The SMR 121 is inserted into the positive electrode line PL1, and the SMRs 122 and 123 are inserted into the negative electrode line NL1. A resistor R1 is connected in series to the SMR 123, and this series connection is connected in parallel to the SMR 122.

  The smoothing capacitor C1 is connected between the positive electrode line PL1 and the negative electrode line NL1, and plays a role of smoothing the voltage between the positive electrode line PL1 and the negative electrode line NL1.

  Boost converter 130 boosts the voltage (that is, power supply voltage) from power storage device 110 and supplies the boosted voltage to inverters 141 and 142. Boost converter 130 steps down the voltage supplied from inverters 141 and 142 to charge power storage device 110.

  In the example of FIG. 3, boost converter 130 includes a reactor L, switching elements (for example, IGBTs) Q1, Q2, and diodes D1, D2. Switching elements Q1, Q2 are connected in series between positive electrode line PL2 and negative electrode line NL1. The collector of switching element Q1 in the upper arm is connected to positive line PL2, and the emitter of switching element Q2 in the lower arm is connected to negative line NL1. One end of the reactor L is connected to an intermediate point between the switching elements Q1 and Q2, that is, a connection point between the emitter of the switching element Q1 and the collector of the switching element Q2. The other end of reactor L is connected to positive electrode line PL1. Further, diodes D1 and D2 are arranged between the collector and emitter of each switching element Q1 and Q2 so that a current flows from the emitter side to the collector side. Boost converter 130 performs voltage conversion by switching (on / off) switching elements Q1, Q2 based on a control signal from control device 180.

  On the boost side of the boost converter 130, a resistor R2, a smoothing capacitor C2, an inverter 141, and an inverter 142 are connected in parallel.

  The smoothing capacitor C2 is connected between the positive electrode line PL2 and the negative electrode line NL1, and plays a role of smoothing the voltage between the positive electrode line PL2 and the negative electrode line NL1.

  Inverter 141 controls rotating electrical machine 151 with the electric power supplied from boost converter 130. Specifically, the inverter 141 converts the DC power supplied from the boost converter 130 into AC power and supplies the AC power to the rotating electrical machine 151, thereby rotating the rotating electrical machine 151. Inverter 141 also converts AC power generated by rotating electric machine 151 into DC power and supplies it to boost converter 130. That is, inverter 141 performs power conversion between boost converter 130 and rotating electric machine 151.

  In the example of FIG. 3, the inverter 141 is configured to include U-phase, V-phase, and W-phase arms arranged in parallel with each other between the positive electrode line PL2 and the negative electrode line NL1. The U-phase arm consists of a series connection of switching elements Q11 and Q12, the V-phase arm consists of a series connection of switching elements Q13 and Q14, and the W-phase arm consists of a series connection of switching elements Q15 and Q16. Switching elements Q11 to Q16 are, for example, IGBTs. Between the collectors and emitters of the switching elements Q11 to Q16, diodes D11 to D16 are arranged to flow current from the emitter side to the collector side, respectively. Inverter 141 performs power conversion by switching (on / off) switching elements Q11 to Q16 based on a control signal from control device 180.

  Inverter 142 controls rotating electric machine 152 by the electric power supplied from boost converter 130. Specifically, the inverter 142 converts the DC power supplied from the boost converter 130 into AC power and supplies the AC power to the rotating electrical machine 152, thereby rotating the rotating electrical machine 152. Inverter 142 also converts AC power generated by rotating electrical machine 152 into DC power and supplies it to boost converter 130. That is, inverter 142 performs power conversion between boost converter 130 and rotating electrical machine 152.

  In the example of FIG. 3, the inverter 142 includes U-phase, V-phase, and W-phase arms arranged in parallel with each other between the positive electrode line PL2 and the negative electrode line NL1. The U-phase arm consists of a series connection of switching elements Q21 and Q22, the V-phase arm consists of a series connection of switching elements Q23 and Q24, and the W-phase arm consists of a series connection of switching elements Q25 and Q26. The switching elements Q21 to Q26 are, for example, IGBTs. Between the collectors and emitters of the respective switching elements Q21 to Q26, diodes D21 to D26 for passing a current from the emitter side to the collector side are arranged. Inverter 142 performs power conversion by switching (on / off) switching elements Q21 to Q26 based on a control signal from control device 180.

  Rotating electric machine 151 includes three stator coils of U, V, and W phases. One end of the three-phase coil is commonly connected to the neutral point N1, the other end of the U-phase coil is at the midpoint between the switching elements Q11 and Q12, and the other end of the V-phase coil is at the midpoint between the switching elements Q13 and Q14. On the other hand, the other end of the W-phase coil is connected to an intermediate point between the switching elements Q15 and Q16. The rotating electrical machine 151 functions as an electric motor driven by electric power from the inverter 141 or a generator that outputs generated electric power to the inverter 141. The rotating electrical machine 151 is, for example, a permanent magnet motor.

  The rotating electrical machine 152 includes three stator coils of U, V, and W phases. One end of the three-phase coil is commonly connected to the neutral point N2, the other end of the U-phase coil is at the midpoint between the switching elements Q21 and Q22, and the other end of the V-phase coil is at the midpoint between the switching elements Q23 and Q24. On the other hand, the other end of the W-phase coil is connected to an intermediate point between the switching elements Q25 and Q26. The rotating electrical machine 152 functions as an electric motor driven by electric power from the inverter 142 or a generator that outputs generated electric power to the inverter 142. The rotating electrical machine 152 is, for example, a permanent magnet motor.

  Here, the electric vehicle 1 is a hybrid vehicle that uses an unillustrated engine and a rotating electric machine as drive sources, and the rotating electric machines 151 and 152 function as follows.

  The rotating electrical machine 151 mainly operates as a generator. Specifically, the rotating electrical machine 151 operates as a motor upon receiving power supply from the inverter 141, and cranks and starts an engine (not shown). The rotating electrical machine 151 is rotated by the driving force of the engine to generate electric power after the engine is started. The AC power generated by the rotating electrical machine 151 is converted into DC power by the inverter 141 and charged in the power storage device 110 or used for driving the rotating electrical machine 152.

  The rotating electrical machine 152 mainly operates as an electric motor. Specifically, the rotating electrical machine 152 is supplied with electric power from the inverter 142 during power running and generates torque for rotationally driving a wheel (not shown). The rotating electrical machine 152 generates power by being rotated by wheels during regenerative braking. The AC power generated by the rotating electrical machine 152 is converted into DC power by the inverter 142 and charged in the power storage device 110.

  Charging device 160 charges power storage device 110 with electric power from external power supply 2 outside the vehicle. The charging device 160 includes a filter 161, a waveform conversion circuit 162, a DC-DC converter 163, a rectifier circuit 164, relays Ry1 and Ry2, a voltage sensor 165, and a control device 166.

  Filter 161 removes harmonic noise on power lines L 11 and L 12 between external power supply 2 and power storage device 110. The filter 161 is connected between the power line L11 and the power line L12, the capacitor connected between the power line L11 and the vehicle body ground, and connected between the power line L12 and the vehicle body ground. A capacitor, an inductor inserted in series with the power line L11 on the external power supply 2 side of the capacitor, and an inductor inserted in series with the power line L12 on the side of the external power supply 2 with respect to the capacitor. Yes.

  A connector 170 is connected to the external power supply 2 side of the filter 161, and a waveform conversion circuit 162 is connected to the power storage device 110 side of the filter 161.

  The waveform conversion circuit 162 converts the sine wave of the AC voltage supplied from the external power supply 2 through the filter 161 and outputs a rectangular wave. The waveform conversion circuit 162 may perform boosting or power factor control. A DC-DC converter 163 is connected to the power storage device 110 side of the waveform conversion circuit 162 via power lines L13 and L14.

  The DC-DC converter 163 is an insulating converter that boosts the voltage from the waveform conversion circuit 162. A rectifier circuit 164 is connected to the power storage device 110 side of the boost converter 163 via power lines L15 and L16.

  The rectifier circuit 164 is a circuit that rectifies the voltage supplied from the boost converter 163 into a DC voltage, and includes a resistor and a capacitor connected between the power line L15 and the power line L16. The positive side of rectifier circuit 164 is connected to the positive electrode of power storage device 110 via power line L17 and positive electrode line PL1, and the negative side of rectifier circuit 164 is the negative electrode of power storage device 110 via power line L18 and negative electrode line NL1. Connected to. Specifically, one end of power line L17 is connected to the positive electrode side of rectifier circuit 164, and the other end of power line L17 is connected to positive electrode line PL1 between SMR 121 and boost converter 130. One end of power line L18 is connected to the negative electrode side of rectifier circuit 164, and the other end of power line L18 is connected to negative electrode line NL1 between SMR 122 and boost converter 130.

  Relays Ry1 and Ry2 open and close a power feeding path from rectifier circuit 164 to power storage device 110. Relays Ry1 and Ry2 are arranged so as not to interrupt the path from power storage device 110 to boost converter 130. Specifically, the relay Ry1 is provided on the positive power line L17, and the relay Ry2 is provided on the negative power line L18. Here, relays Ry1 and Ry2 are normally open, and are closed when there is a connection command from control device 180 or 166, and open when there is no connection command.

  Voltage sensor 165 detects the voltage between power lines L17 and L18 on the external power supply 2 side of relays Ry1 and Ry2. The voltage sensor 165 is provided between the relays Ry1 and Ry2 and the rectifier circuit 164.

  The control device 166 controls the operation of the charging device 160 and includes, for example, a microcomputer. Specifically, control device 166 controls waveform conversion circuit 162 and boost converter 163.

  The connector 170 is an interface for connecting the external power supply 2 to the vehicle. The external power source 2 is connected to the connector 170 when the power storage device 110 is charged. Specifically, the connector 170 is connected to the external power source 2 via the charging cable unit 200. The charging cable unit 200 includes power lines L21 and L22, a connector 201 connected to one end of the power lines L21 and L22, a connector 202 connected to the other end of the power lines L21 and L22, and a connector 201 and a connector 202. And an outside unit 203 provided between the two. When the power storage device 110 is charged, the connector 201 is connected to the connector 170, and the connector 202 is connected to the connector (for example, outlet) 3 on the external power supply 2 side. The vehicle exterior unit 203 includes a relay inserted in the power lines L21 and L22, a leakage detection circuit, and the like.

  In the above configuration, the high-voltage components such as the inverters 141 and 142 and the charging device 160 and the lines connecting them are mounted on the vehicle body, and are connected to the vehicle body ground via a capacitance such as a stray capacitance. FIG. 3 exemplarily shows the capacity between the U, V, W phase lines of the inverters 141 and 142 and the vehicle body ground, and the capacity between the power line L18 of the charging device 160 and the vehicle body ground. ing.

  The control device 180 controls the operation of the electric vehicle 1 and is, for example, an electronic control unit (ECU).

  Specifically, control device 180 controls rotating electric machines 151 and 152 by controlling the switching operations of inverters 141 and 142 during vehicle travel. In addition, when charging power storage device 110 with external power supply 2, control device 180 controls SMR 121 and 122 and relays Ry 1 and Ry 2 to be in a closed state, and controls control device 166 to use power from external power supply 2. The power storage device 110 is charged.

  Further, control device 180 performs welding determination of relays Ry1 and Ry2. Hereinafter, this welding determination will be described.

  During the switching operation of the inverter 141 or 142, switching noise (high-frequency noise) is generated, and the potential of the high-voltage circuit with respect to the vehicle body ground (for example, the potential of the positive line PL1, the negative line NL1, etc.) varies. At this time, if the relay Ry1 is in the connected state, the potential of the power line L17 on the external power source 2 side of the relay Ry1 varies, and if the relay Ry2 is in the connected state, the power line L18 on the external power source 2 side of the relay Ry2. Fluctuations occur in the potential.

  4 is a waveform diagram schematically showing the potential when the positive-side relay Ry1 is in a connected state, and FIG. 5 is a waveform diagrammatically showing the potential when the negative-side relay Ry2 is in a connected state. FIG. 4 and 5, the vertical axis represents the potential with respect to the vehicle body ground, and the horizontal axis represents time. The solid line VP represents the potential of the positive power line L17 on the external power supply side of the relay, and the solid line VN represents the potential of the negative power line L18 on the external power supply side of the relay.

  As shown in FIG. 4, when the positive-side relay Ry1 is in the connected state, the potential of the negative-side power line L18 is substantially zero, while the positive-side power line L17 is relatively low due to switching noise. A positive potential with a large absolute value appears.

  Further, as shown in FIG. 5, when the negative side relay Ry2 is in the connected state, the potential of the positive power line L17 is substantially zero, while the negative power line L18 is caused by switching noise. A negative potential having a relatively large absolute value appears.

  4 and 5, the potential difference (VP−VN) between the potential VP and the potential VN is a voltage applied to the voltage sensor 165 due to switching noise.

  Therefore, when the voltage due to switching noise is detected by the voltage sensor 165 even though the relays Ry1 and Ry2 are controlled to be in the open state, it is considered that the relay Ry1 or Ry2 is likely to be welded. It is done.

  Therefore, the control device 180 does not issue a connection command to the relays Ry1 and Ry2 during the switching operation of the inverter 141 or 142 (that is, while controlling the relays Ry1 and Ry2 to be in the open state), and detects the detected value of the voltage sensor 165. Monitoring is performed, and welding determination of the relays Ry1 and Ry2 is performed based on the detected value. Specifically, control device 180 determines that the relay is welded when voltage sensor 165 detects a voltage equal to or higher than a predetermined threshold.

(Second specific example)
FIG. 6 is a configuration diagram showing a second specific example of electrically powered vehicle 1 according to the present embodiment. Hereinafter, a second specific example of the electric vehicle 1 will be described with reference to FIG. Since the second specific example is almost the same as the first specific example, portions common to the first specific example are denoted by the same reference numerals and description thereof is omitted.

  The electric vehicle 1 of this example has a plurality of power storage devices from the viewpoint of increasing the storage capacity. In FIG. 6, electric vehicle 1 includes power storage devices 110-1 and 110-2 in addition to power storage device 110. Here, the power storage device 110 is, for example, a master battery, and the power storage devices 110-1 and 110-2 are, for example, first and second slave batteries. However, the number of additional power storage devices is not limited to two, and may be one or three or more.

  Similarly to power storage device 110, positive electrode line PL1-1, negative electrode line NL1-1, SMRs 121-1, 122-1, 123-1 and resistor R1-1 are connected to power storage device 110-1.

  Similarly, positive electrode line PL1-2, negative electrode line NL1-2, SMRs 121-2, 122-2, 123-2, and resistor R1-2 are also connected to power storage device 110-2.

  Smoothing capacitor C1-1 and slave boost converter 130-1 are connected to power storage devices 110-1 and 110-2.

  Boost converter 130-1 boosts the voltage from power storage devices 110-1 and 110-2 and supplies the boosted voltage to inverters 141 and 142. Boost converter 130-1 steps down the voltage supplied from inverters 141 and 142 and charges power storage devices 110-1 and 110-2. Boost converter 130-1 includes a reactor L-1, switching elements (eg, IGBTs) Q1-1 and Q2-1, and diodes D1-1 and D2-1, similarly to master boost converter 130. Switching elements Q1-1 and Q2-1 are connected in series between positive electrode line PL2-1 and negative electrode line NL1-1. The collector of upper-arm switching element Q1-1 is connected to positive line PL2-1, and the emitter of lower-arm switching element Q2-1 is connected to negative line NL1-1. One end of reactor L-1 is connected to an intermediate point of switching elements Q1-1 and Q2-1, that is, a connection point between the emitter of switching element Q1-1 and the collector of switching element Q2-1. The other end of reactor L-1 is connected to positive electrode lines PL1-1 and PL1-2. In addition, diodes D1-1 and D2-1 are arranged between the collector and emitter of each switching element Q1-1 and Q2-1 so that a current flows from the emitter side to the collector side. Boost converter 130-1 performs voltage conversion by switching (on / off) switching elements Q1-1 and Q2-1 based on a control signal from control device 180.

  Positive line PL2-1 is connected to positive line PL2, and negative line NL1-1 is connected to negative line NL1.

  In this example, power lines L17 and L18 of charging device 160 are connected to positive line PL1-1 and negative line NL1-1, respectively, between SMRs 121-1 and 122-1 and boost converter 130-1. .

  When charging power storage device 110 with external power supply 2, control device 180 controls SMR 121 and 122 and relays Ry 1 and Ry 2 to a closed state, controls switching element Q 1 to an on state, and controls control device 166. Then, the power storage device 110 is charged with the electric power of the external power source 2.

  In addition, when charging power storage device 110-1 with external power supply 2, control device 180 controls SMRs 121-1 and 122-1 and relays Ry <b> 1 and Ry <b> 2 to be closed and controls control device 166 to control power storage device 110-1. The power storage device 110-1 is charged with the electric power of the external power source 2.

  Similarly, when charging power storage device 110-2 with external power supply 2, control device 180 controls SMRs 121-2 and 122-2 and relays Ry1 and Ry2 to be closed and controls control device 166. Then, the power storage device 110-2 is charged with the electric power of the external power source 2.

  Similarly to the first specific example, the control device 180 does not issue a connection command to the relays Ry1 and Ry2 during the switching operation of the inverter 141 or 142 (that is, while controlling the relays Ry1 and Ry2 to the open state). The detection value of voltage sensor 165 is monitored, and welding determination of relays Ry1 and Ry2 is performed based on the detection value.

  In the electric vehicle 1 having the above configuration, as a welding determination method different from the present embodiment, a connection command is given to one of the two relays Ry1 and Ry2, and at this time, the power line on the external power source 2 side of the two relays A method of monitoring the voltage between L17 and L18 with the voltage sensor 165 and determining that the other relay is welded when a voltage equal to or higher than a predetermined threshold is detected is assumed. That is, a method of performing relay welding determination using the voltage of the power storage device is conceivable.

  FIG. 7 is a sequence diagram showing an example of the operation of the welding determination method different from the present embodiment. FIG. 8 is a sequence diagram showing an example of the operation of the welding determination method of the present embodiment.

  7 and 8, master SMRs 121, 122, slave SMRs 121-1, 122-1, positive side relay Ry1, negative side relay Ry2, and switching on / off of inverters 141, 142, and voltage sensors are shown. A detection value of 165 is shown.

  7 and 8, the master SMRs 121 and 122 are turned on, the inverter is switched, and the rotating electrical machine is driven and controlled by the electric power of the master power storage device 110.

  In this case, in FIG. 7, the welding determination of the relays Ry1 and Ry2 is performed using the voltage of the slave power storage device 110-1. Specifically, when the slave SMRs 121-1 and 122-1 are turned on, an ON command (connection command) is given to the relay Ry 1, and at this time, when the voltage sensor 165 detects a voltage value equal to or higher than a predetermined threshold value. It is determined that the relay Ry2 is welded. Further, when the slave SMRs 121-1 and 122-1 are turned on, an on command (connection command) is given to the relay Ry 2, and when a voltage value equal to or higher than a predetermined threshold is detected by the voltage sensor 165 at this time, the relay Ry 1 Is determined to be welded. Ideally, when the relays Ry1 and Ry2 are not welded, no voltage is applied to the voltage sensor 165 even if one of the relays is connected. However, if one of the relays is connected during the switching operation of the inverter, the voltage due to the switching noise is applied to the voltage sensor 165, so that relay welding may be erroneously determined.

  On the other hand, in FIG. 8, since it is not necessary to apply the voltage of the power storage device to the relay, the slave SMRs 121-1, 122-1 do not need to be turned on and are not turned on. Also, no ON command (connection command) is given to the relays Ry1 and Ry2. Therefore, when the relays Ry1 and Ry2 are not welded, the voltage sensor 165 is not applied with a voltage due to switching noise, and it is determined that there is no relay welding. On the other hand, when at least one relay is welded, a voltage due to switching noise is applied to the voltage sensor 165, and it is determined that there is relay welding.

  In addition, this invention is not limited to the said embodiment, It can change variously within the range which does not deviate from the summary of this invention.

  DESCRIPTION OF SYMBOLS 1 Electric vehicle, 10 Power storage device, 20 Inverter, 30 Rotating electric machine, 40 Charging device, 41, 42 Relay, 50 Control device.

Claims (3)

A power storage device;
An inverter that drives a rotating electric machine for traveling with electric power of the power storage device;
A charging device that converts an alternating current of the external power source into a direct current in order to charge the power storage device with electric power from an external power source, and the external power supply is not cut off from a path between the power storage device and the inverter. A charging device including a pair of relays for opening and closing a power supply path from a power source to the power storage device;
During switching operation of the inverter, while controlling the respective relays in the open state, the detected voltage caused by the switching noise of the inverter in the external power supply side of each relay, each relay on the basis of the detection result A welding determination device for determining whether or not at least one of these is welded,
An electric vehicle comprising: A power storage device;
An inverter that drives a rotating electric machine for traveling with electric power of the power storage device;
A charging device that converts an alternating current of the external power source into a direct current in order to charge the power storage device with electric power from an external power source, and the external power supply is not cut off from a path between the power storage device and the inverter. A charging device including a pair of relays for opening and closing a power supply path from a power source to the power storage device;
A welding determination device for an electric vehicle having
During switching operation of the inverter, a voltage detecting means for detecting the while controlling the relays to the open state, the voltage caused by the switching noise of the inverter in the external power supply side of each relay,
And determining the welding judging means for judging whether at least one is welded detection result on the basis of the respective relay the voltage detecting means,
The welding determination apparatus characterized by having. A power storage device;
An inverter that drives a rotating electric machine for traveling with electric power of the power storage device;
A charging device that converts an alternating current of the external power source into a direct current in order to charge the power storage device with electric power from an external power source, and the external power supply is not cut off from a path between the power storage device and the inverter. A charging device including a pair of relays for opening and closing a power supply path from a power source to the power storage device;
A welding determination program for an electric vehicle having a computer,
During switching operation of the inverter, a voltage detection procedure for detecting the while controlling the relays to the open state, the voltage caused by the switching noise of the inverter in the external power supply side of each relay,
And the welding determination procedure for determining whether at least one of said each relay is welded based on a detection result of said voltage detection procedure,
A welding determination program characterized in that

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