Electric Vehicles

Abstract

To provide an electric vehicle configured so that safety can be enhanced.SOLUTION: An electric vehicle comprises: a mounted object that is operated by electric power; and a vehicle body that is mounted with the mounted object. The electric vehicle further comprises: a battery that supplies electric power to an electric motor for operating the vehicle body; a first electric power supply line through which electric power is supplied from the battery to the mounted object; a third electric power supply line through which electric power is supplied from a rapid charger to the battery; a first protection circuit which is provided on the first electric power supply line and which can cut off electric power; a third protection circuit which is provided on the third electric power supply line and which can cut off electric power; and a control part that, when key-off operation is performed and when determining whether or not the first protection circuit and the third protection circuit are each failed welded by heat and then determining that at least one of the first protection circuit and the third protection circuit has been failed welded by heat, stores information indicating the failure due to being welded by heat, and when the vehicle body is operated next time, executes control of transmitting the information indicating the failure due to being welded by heat, onto a CAN path.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to electric vehicles. [Background technology]

[0002] In general, an electric vehicle is a vehicle equipped with a battery and a traction motor that is driven by the power of the battery.

[0003] Moreover, in recent years, from the viewpoint of reducing the environmental load, electric vehicles in which mounted equipment for performing predetermined work is operated by battery power have become known as work vehicles.

[0004] The battery may be charged at a high voltage by a quick charger installed outside the vehicle. In this case, the vehicle is provided with a charging connector for connecting the quick charger and a power supply line for supplying power from the charging connector to the battery.

[0005] For example, Patent Document 1 describes a control device that includes a charging plug (connector) to which a charger is connected, a power supply line that supplies power from the charging plug to a battery, a relay circuit arranged on the power supply line, and a charging control device that controls charging of the battery. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-44929 Summary of the Invention [Problem to be solved by the invention]

[0007] However, for example, if a relay circuit arranged on a power supply line for rapid charging suffers a welding fault, high voltage is exposed to the charging plug (connector), posing a risk of electric shock to a user who touches the connector, and therefore there is a need to improve safety.

[0008] An object of the present disclosure is to provide an electric vehicle that can improve safety. [Means for solving the problem]

[0009] In order to achieve the above object, the electric vehicle in the present disclosure includes: An electric vehicle having an attachment that operates by electric power and a vehicle body on which the attachment is mounted, a battery for supplying power to an electric motor for operating the vehicle body; A first power supply line arranged on the vehicle body side for supplying power from the battery to the mounted object; A second power supply line arranged on the mounting side for supplying power from the battery to the mounting; a third power supply line for supplying power from a quick charger to the battery; a first protection circuit provided on the first power supply line and capable of cutting off power; a second protection circuit provided on the second power supply line and capable of cutting off power; a third protection circuit provided on the third power supply line and capable of cutting off power; A battery relay that is disposed between the battery and the first power supply line and is capable of cutting off the power supplied from the battery to the mounted object. circuit and, A control unit that controls a battery relay circuit to cut off power supplied from the battery to the mounted object when the first protection circuit has a welding failure and when the state of the second protection circuit has a welding failure; Equipped with picture, When a key-off operation is performed and the control unit determines whether or not each of the first protection circuit and the third protection circuit has a welding fault, and when it is determined that at least one of the first protection circuit and the third protection circuit has a welding fault, stores information indicating the welding fault, and executes control to transmit the information indicating the welding fault onto a CAN bus when the vehicle body is next operated. do. Effect of the Invention

[0010] According to the present disclosure, safety can be improved. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a diagram illustrating an example of a power system of an electric vehicle according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram illustrating an example of a quick-charging relay circuit. [Diagram 3] FIG. 3 is a configuration block diagram showing an example of a power system of an electric vehicle according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a flowchart showing the operation of the control unit of the power system according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. 1 is a diagram showing an example of a power system of an electric vehicle in an embodiment of the present disclosure. An electric vehicle 100 (Electric Vehicle: EV) in this embodiment is an electric work vehicle having a vehicle body 110 equipped with a battery 111, an electric motor 112 for running driven by the power of the battery 111, and an attached object 150 for performing a predetermined work by the power of the battery 111. Note that the electric vehicle 100 in this embodiment has a load (not shown) such as a heater in addition to the electric motor 112 and the attached object 150, but in order to simply explain the embodiment, a description of these loads will be omitted.

[0013] (Battery 111) The battery 111 is a secondary battery that is charged by an external power source. The battery 111 has one or more battery packs BP. Since each of the multiple battery packs BP has the same configuration, one battery pack BP among the multiple battery packs BP will be described as a representative. The battery pack BP has multiple cells 111a, a battery relay (+) 111b, a battery relay (-) 111c, and a battery pack management system 117P (PBMS). The battery relay (+) 111b and the battery relay (-) 111c are collectively referred to as "battery relay circuit 116B." The battery relay circuit 116B may be referred to as a "fourth protection circuit."

[0014] One terminal of the battery relay (+) 111b is connected to the positive terminal of the cell 111a via the high voltage line 111L(+). The other terminal of the battery relay (+) 111b is connected to the high voltage line 122L(+). One terminal of the battery relay (-) 111c is connected to the negative terminal of the cell 111a via the high voltage line 111L(-). The other terminal of the battery relay (-) 111c is connected to the high voltage line 122L(-).

[0015] The cell 111a has a temperature sensor 111e and a voltage sensor 111f. The temperature sensor 111e detects the cell temperature. The temperature sensor 111e outputs the detection result (cell temperature) to the battery pack management system 117P. The voltage sensor 111f detects the cell voltage. The voltage sensor 111f outputs the detection result (cell voltage) to the battery pack management system 117P. The voltage sensor 111f may be referred to as a "fourth detection unit."

[0016] The battery pack management system 117P controls the battery relay (+) 111b to connect / disconnect between the high voltage line 111L(+) and the high voltage line 122L(+) based on the input cell temperature and cell voltage, respectively, and controls the battery relay (-) 111c to connect / disconnect between the high voltage line 111L(-) and the high voltage line 122L(-).

[0017] (Junction Box JB) The vehicle body 110 has a junction box JB. The junction box JB is disposed between the battery pack BP and the electric motor 112 and the quick charger 130Q. The junction box JB has a quick charging relay circuit 116Q, a power extraction relay circuit 116T, and a battery management system 117J (MBMS). The battery pack management system 117P and the battery management system 117J are collectively referred to as the "battery management unit 117." The power extraction relay circuit 116T may be referred to as the "first protection circuit."

[0018] One terminal (+) of the quick charging relay circuit 116Q is connected to the high voltage line 122L(+). The other terminal (+) of the quick charging relay circuit 116Q is connected to the connector 121CQ via the high voltage line 121LQ(+). One terminal (-) of the quick charging relay circuit 116Q is connected to the high voltage line 122L(-). The other terminal (-) of the quick charging relay circuit 116Q is connected to the connector 121CQ via the high voltage line 121LQ(-). The battery management system 117J controls the quick charging relay circuit 116Q to connect / disconnect between the high voltage line 122L(+) and the high voltage line 121LQ(+) and to connect / disconnect between the high voltage line 122L(-) and the high voltage line 121LQ(-) based on an instruction from a vehicle control unit 118 (Vehicle Control Unit: VCU). In the following description, the high voltage line 121LQ(+) and the high voltage line 121LQ(-) are collectively referred to as the "power supply line 121LQ." Furthermore, the high voltage line 122L(+) and the high voltage line 122L(-) are collectively referred to as the "power supply line 122L." The power supply line 121LQ and the power supply line 122L may be referred to as the "third power supply line."

[0019] (Connector 121CQ) (Vehicle 110) Vehicle body 110 has connector 121CQ. Connector 121CQ is also called a charging port. Connector 121CQ is a connector for quick charging to which connector 131CQ can be electrically connected.

[0020] (Quick charger 130Q) Rapid charger 130Q is provided outside vehicle body 110. Rapid charger 130Q has a charging cable 131Q extending from its body, and a connector 131CQ provided at the tip of charging cable 131Q. Rapid charger 130Q is capable of charging battery 111 at high voltage by electrically connecting connector 131CQ to connector 121CQ.

[0021] The vehicle body 110 has an ignition switch (not shown) which is a switch for turning on / off a starter relay (not shown). For example, when the starter relay is turned on (key-on), power is sent from the battery 111 to a coil (not shown) of the battery relay circuit 116B. This turns on the battery relay circuit 116B, so that power is supplied from the battery 111 to the electric motor 112 via the battery relay circuit 116B (operation of the electric motor). When the starter relay is turned off (key-off), the battery relay circuit 116B turns off, so that power from the battery 111 to the electric motor 112 is cut off (stopping of the electric motor).

[0022] (Power supply line 121LQ, power supply line 122L, quick charging relay circuit 116Q) As shown in FIG. 1, a rapid charging relay circuit 116Q is provided on the power supply lines 121LQ and 122L. The power supply line 121LQ electrically connects the connector 121CQ and the rapid charging relay circuit 116Q. The power supply line 121LQ has a high voltage line 121LQ(+) and a high voltage line 121LQ(-). The power supply line 122L electrically connects the battery 111 and the rapid charging relay circuit 116Q. The power supply line 122L has a high voltage line 122L(+) and a high voltage line 122L(-). The rapid charging relay circuit 116Q may be referred to as a "third protection circuit."

[0023] FIG. 2 is a diagram showing an example of a quick-charging relay circuit. The quick-charging relay circuit 116Q has a relay (+) and a relay (-). The relay (+) has a coil (not shown), one terminal (+), the other terminal (+), a movable contact MC, a fixed contact FC on one side provided on the one terminal (+) side, and a fixed contact FC on the other side provided on the other terminal (+). A high-voltage line 121LQ(+) is connected to one terminal (+) of the relay (+). A high-voltage line 122L(+) is connected to the other terminal (+) of the relay (+). The relay (-) has a coil (not shown), one terminal (-), the other terminal (-), a movable contact MC, a fixed contact FC on one side provided on the one terminal (-) side, and a fixed contact FC on the other side provided on the other terminal (-). A high-voltage line 121LQ(-) is connected to one terminal (-) of the relay (-). The other terminal (-) of the relay (-) is connected to a high voltage line 122L (-).

[0024] In each of the relays (+) and (-), when a current flows through the coil, the movable contact MC is attracted by an electromagnetic force, and the movable contact MC electrically contacts the fixed contact FC on one side and the fixed contact FC on the other side. When no current flows through the coil, the movable contact MC returns to its original position and separates from the fixed contact FC on one side and the fixed contact FC on the other side. When the movable contact MC of the relay (+) separates from the fixed contact FC on one side and the fixed contact FC on the other side of the relay (+), or when the movable contact MC of the relay (-) separates from the fixed contact FC on one side and the fixed contact FC on the other side of the relay (-), the power supply lines 121LQ and 122L are electrically disconnected. This makes it possible to cut off the power supplied from the quick charger 130Q to the battery 111.

[0025] In either relay (+) or relay (-) of quick charging relay circuit 116Q, a state in which the movable contact MC is welded to each of the fixed contact FC on one side and the fixed contact FC on the other side and cannot be separated is called a "welding failure of the relay," "single welding failure of the relay," or simply "single welding failure." In addition, in either relay (+) or relay (-), a state in which the movable contact MC is welded to each of the fixed contact FC on one side and the fixed contact FC on the other side and cannot be separated is called a "double welding failure of the relay" or simply "double welding failure." In addition, either or both of the single welding failure and the double welding failure are collectively called a "welding failure."

[0026] (Power supply line 122L, power supply line 123L, power extraction relay circuit 116T) As shown in Fig. 1, the power supply lines 122L, 123L are provided with a power extraction relay circuit 116T. The power supply line 122L electrically connects the battery 111 and the power extraction relay circuit 116T. The power supply line 123L electrically connects the power extraction relay circuit 116T and the connector 123C. The power supply line 123L has a high voltage line 123L(+) and a high voltage line 123L(-). The power supply line 122L and the power supply line 123L may be referred to as a "first power supply line."

[0027] The power extraction relay circuit 116T has a relay (+) and a relay (-). The relay (+) and relay (-) have the same configuration as the relay (+) and relay (-) in the quick charging relay circuit 116Q, and therefore the same components are given the same reference numerals and their description is omitted. A high voltage line 122L(+) is connected to one terminal (+) of the relay (+). A high voltage line 123L(+) is connected to the other terminal (+) of the relay (+). A high voltage line 122L(-) is connected to one terminal (-) of the relay (-). A high voltage line 123L(-) is connected to the other terminal (-) of the relay (-).

[0028] The power supplied from the battery 111 to the equipment 150 (equipment relay circuit 156) can be cut off by moving the movable contact MC of the relay (+) away from the fixed contact FC on one side of the relay (+) and the fixed contact FC on the other side, or by moving the movable contact MC of the relay (-) away from the fixed contact FC on one side of the relay (-) and the fixed contact FC on the other side.

[0029] In either the relay (+) or relay (-) of the power extraction relay circuit 116T, a state in which the movable contact MC is welded to each of the fixed contacts FC on one side and the fixed contacts FC on the other side and cannot be separated is called a "welding failure of the relay," "single welding failure of the relay," or simply "single welding failure." In addition, in either the relay (+) or relay (-), a state in which the movable contact MC is welded to each of the fixed contacts FC on one side and the fixed contacts FC on the other side and cannot be separated is called a "double welding failure of the relay" or simply "double welding failure." In addition, either or both of the single welding failure and double welding failure are collectively called a "welding failure."

[0030] (Connector 123C) The connector 123C is electrically connected to a connector 153C provided on the mounting 150.

[0031] (Mounted object 150) 3, in addition to the connector 153C, the mounting 150 has a load (not shown), a power supply line 153L, a communication unit 155, a mounting relay circuit 156, a detection unit 157, and a control unit 158. The mounting relay circuit 156 may be referred to as a "second protection circuit."

[0032] (Power supply line 153L, bodywork relay circuit 156) The high voltage line 153L electrically connects the connector 153C and the body relay circuit 156. The power supply line 153L has a high voltage line 153L(+) and a high voltage line 153L(-). The body relay circuit 156 has a relay (+) and a relay (-). The relay (+) and the relay (-) have the same configuration as the relay (+) and the relay (-) in the quick charging relay circuit 116Q, so the same reference numerals are used for the same configuration and the description thereof is omitted. The high voltage line 153L(+) is connected to one terminal (+) of the relay (+). The high voltage line 153L(-) is connected to one terminal (-) of the relay (-).

[0033] (Load of 150 bodywork) The load (not shown) is, for example, an electric motor. The load is electrically connected to the body relay circuit 156 via a power supply line (not shown). That is, the load (electric motor) operates with power received from the battery 111 via the power supply line 122L, the power extraction relay circuit 116T, the power supply line 123L, the power supply line 153L, the body relay circuit 156, and the power supply line (not shown). The power supply line (not shown) has a high voltage line (+) and a high voltage line (-). The high voltage line (+) is connected to the other terminal (+) of the relay (+). The high voltage line (-) is connected to the other terminal (-) of the relay (-). The power supply line 153L and the power supply line (not shown) may be referred to as a "second power supply line". The control unit 158 ​​controls the body relay circuit 156 to close / open, thereby electrically connecting / disconnecting the second power supply line.

[0034] The relay (+) and relay (-) in the mounting relay circuit 156 have the same configuration as the relay (+) and relay (-) in the quick charging relay circuit 116Q, so the same components are given the same reference numerals and their description is omitted.

[0035] When the movable contact MC of the relay (+) is separated from the fixed contact FC on one side of the relay (+) and the fixed contact FC on the other side, or when the movable contact MC of the relay (-) is separated from the fixed contact FC on one side of the relay (-) and the fixed contact FC on the other side, it is possible to cut off the power supplied from the battery 111 to the load (not shown) via the power supply line 153L and the power supply line (not shown). In either the relay (+) or the relay (-) of the bodywork relay circuit 156, a state in which the movable contact MC is welded to each of the fixed contact FC on one side and the fixed contact FC on the other side and cannot be separated is called a "welding failure of the relay," "single welding failure of the relay," or simply a "single welding failure." In addition, in each of the relay (+) and the relay (-), a state in which the movable contact MC is welded to each of the fixed contact FC on one side and the fixed contact FC on the other side and cannot be separated is called a "double welding failure of the relay" or simply a "double welding failure." In addition, either or both of a single welding fault and a double welding fault are collectively referred to as a "welding fault."

[0036] (Detection unit 157) The detection unit 157 detects each of the states of the mounting relay circuit 156, open, closed, open failure, and welded failure (closed failure). The detection unit 157 also outputs an error signal indicating that the state of the mounting relay circuit 156 cannot be detected. The detection unit 157 may be referred to as a "second detection unit." The detection signals for the open failure and welded failure, as well as the error signal, may be referred to as "abnormality signals from the mounting side" or simply as "abnormality signals."

[0037] (Control unit 158) The control unit 158 ​​is a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and executes a program stored in a storage device (not shown) to centrally control a plurality of devices constituting the mounting 150. The control unit 158 ​​also acquires an abnormality signal and controls the communication unit 155 to transmit the acquired abnormality signal to the communication unit 115.

[0038] (Communications Department 155) Information is exchanged between the communication units 155 and 115 via any means. For example, the communication units 155 and 115 are connected to each other via a communication network NW having a function of wirelessly communicating over the Internet. This enables the communication unit 155 to transmit an abnormality signal from the mounted object 150 side to the vehicle body 110 side.

[0039] (Communication section 115) Communication unit 115 transmits and receives information to and from communication unit 155. Communication unit 115 may be referred to as a "receiving unit." Communication unit 155 may be referred to as a "transmitting unit."

[0040] (Storage unit 113) The memory unit 113 is a storage device such as a ROM (Read Only Memory) that stores the BIOS (Basic Input Output System) of a computer that realizes the control unit 119, a RAM (Random Access Memory) that serves as the working area of ​​the control device 20, an HDD (Hard Disk Drive) or an SSD (Solid State Drive) that stores the OS (Operating System), application programs, and various information referenced when the application programs are executed.

[0041] (Control unit 119) Next, the control unit 119 will be described with reference to Figures 1 and 3. Figure 3 is a functional block diagram showing an example of a power system of an electric vehicle according to an embodiment of the present disclosure.

[0042] The control unit 119 is a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and has various functions by executing programs stored in the storage unit 113.

[0043] From the viewpoint of improving safety and protecting the battery 111, the control unit 119 executes control according to the respective states of the quick charging relay circuit 116Q, the power extraction relay circuit 116T, and the mounting relay circuit 156.

[0044] The control unit 119 stores predetermined information in the memory unit 113. The control unit 119 also displays the predetermined information on the display unit 140. Note that the predetermined information stored in the memory unit 113 is, for example, information indicating a welding failure (single welding failure, double welding failure) of each of the quick charging relay circuit 116Q and the power extraction relay circuit 116T.

[0045] The control unit 119 is realized by, for example, a plurality of processors, a memory, and other computational resources. In this case, each component constituting the control unit 119 is realized by at least one of a plurality of different processors executing a program. The control unit 119 may be configured by a single device. In this case, for example, the control unit 119 may be configured by all of the battery management unit 117 and the vehicle control unit 118 shown in FIG. 3. The control unit 119 may also be configured by a plurality of devices. In this case, for example, the control unit 119 may be configured by each of the battery management unit 117 and the vehicle control unit 118, or may be configured by a combination of the battery management unit 117 and the vehicle control unit 118 and another device.

[0046] As described above, the battery pack management system 117P and the battery management system 117J are collectively referred to as the "battery management unit 117." In this embodiment, the battery management unit 117 and the vehicle control unit 118 are included in the control unit 119. Note that the battery management unit 117 may be provided in the vehicle body 110 as a device separate from the vehicle control unit 118.

[0047] (Battery management unit 117) The battery management unit 117 controls the battery relay 116B to close / open so as to connect / disconnect the high voltage line 111L and the power supply line 122L based on the state of the battery 111 (eg, cell temperature, cell voltage).

[0048] Furthermore, the battery management unit 117 controls the quick charging relay circuit 116Q to close / open so as to connect / disconnect the power supply line 121LQ and the power supply line 122L based on the state of the battery 111 (eg, State Of Charge: SOC).

[0049] The battery management unit 117 also has a third detection unit (not shown) that detects each of the states of the quick charging relay circuit 116Q, namely, open, closed, open failure, and welding failure (close failure). The third detection unit outputs a relay state signal indicating the state of the quick charging relay circuit 116Q as a detection result. The third detection unit also outputs an error signal indicating that the state of the quick charging relay circuit 116Q cannot be detected.

[0050] Furthermore, the battery management unit 117 judges whether or not a welding failure (single welding failure, double welding failure) has occurred in the quick charging relay circuit 116Q based on the detection result of the third detection unit (welding diagnosis). The battery management unit 117 performs a welding diagnosis at a predetermined timing and transmits the information (the judgment result for the quick charging relay circuit 116Q) to the vehicle control unit 118 via a control area network (CAN). For example, the battery management unit 117 performs a welding diagnosis when the key is turned off, stores the information in, for example, an internal memory, and transmits the information via the CAN to the vehicle control unit 118 the next time the key is turned on (at startup). Here, "transmitting information via the CAN" refers to transmitting information onto a CAN bus.

[0051] Furthermore, when the rapid charging relay circuit 116Q has a double welding fault, the battery management unit 117 controls the battery relay circuit 116B to be open.

[0052] In addition, when the state of the power extraction relay circuit 116T (first protection circuit) is a closed failure and when the detection result of the detection unit 157 (second detection unit) indicates that the state of the mounting relay circuit 156 (second protection circuit) is either a closed, closed failure, or an open failure, the battery management unit 117 controls the battery relay circuit 116B to cut off the power supplied from the battery 111 to the mounting object 150 side.

[0053] Furthermore, when the rapid charging relay circuit 116Q has a single welding fault, the battery management unit 117 controls the rapid charging relay circuit 116Q to be open even when a close request is received from the higher-level vehicle control unit 118.

[0054] Furthermore, the battery management unit 117 determines whether or not the third detection unit is malfunctioning based on the error signal output from the third detection unit. The battery management unit 117 transmits the determination result regarding the third detection unit to the vehicle control unit 118 via the CAN.

[0055] Furthermore, when the battery management unit 117 receives an abnormality signal (an abnormality signal from an equipment) from the vehicle control unit 118, it performs a protective operation as the battery management unit 117, for example, controls the power extraction relay circuit 116T to open.

[0056] The battery management unit 117 also has a first detection unit (not shown) that detects the open, closed, open failure, and welded failure (close failure) states of the power extraction relay circuit 116T. The first detection unit outputs a relay state signal indicating the state of the power extraction relay circuit 116T as a detection result. The first detection unit also outputs an error signal indicating that the state of the power extraction relay circuit 116T cannot be detected.

[0057] Furthermore, the battery management unit 117 judges whether or not a welding failure (single welding failure, double welding failure) has occurred in the power extraction relay circuit 116T based on the detection result of the first detection unit (welding diagnosis). The battery management unit 117 performs a welding diagnosis at a predetermined timing and transmits the information (the judgment result for the power extraction relay circuit 116T) via the CAN to the vehicle control unit 118. For example, the battery management unit 117 performs a welding diagnosis when the key is turned off, stores the information in, for example, an internal memory, and transmits the information via the CAN to the vehicle control unit 118 the next time the key is turned on (at startup).

[0058] Furthermore, the battery management unit 117 determines whether or not the first detection unit is malfunctioning based on the error signal output from the first detection unit. The battery management unit 117 transmits the determination result regarding the first detection unit to the vehicle control unit 118 via the CAN.

[0059] (Vehicle control unit 118) The vehicle control unit 118 (VCU) judges the state of the electric vehicle 100 and executes control to maintain the electric vehicle 100 in an optimal state. Specifically, when the vehicle control unit 118 detects an abnormality in the electric vehicle 100, it controls the electric motor 112 to stop the electric vehicle 100. Furthermore, the vehicle control unit 118 controls the power supplied from the battery 111 to the electric motor 112 by changing the voltage between the battery 111 and the electric motor 112. Furthermore, the vehicle control unit 118 controls the power supplied from the battery 111 to a heater (not shown) by changing the voltage between the battery 111 and a heater (not shown). Furthermore, the vehicle control unit 118 controls the quick charger 130Q so that the charging power when charging the battery 111 does not exceed the chargeable power, for example.

[0060] Furthermore, when the state of the power extraction relay circuit 116T (first protection circuit) is a closed fault and when the detection result of the detection unit 157 (second detection unit) indicates an initial value or when the state of the mounting relay circuit 156 (second protection circuit) indicates an open state, the vehicle control unit 118 executes control not to supply power from the battery 111 to the mounting 150. Specifically, the mounting 150 is prohibited from use. Also, an instruction is given to the mounting 150 to stop operation.

[0061] Furthermore, when a first detection unit that detects the state of the power extraction relay circuit 116T (first protection circuit) outputs an error signal (when it is broken), the vehicle control unit 118 executes control to deal with the error signal depending on the state of the power extraction relay circuit 116T when the error signal was output, etc. When a third detection unit that detects the state of the quick charging relay circuit 116Q (third protection circuit) outputs an error signal (when it is broken), the vehicle control unit 118 executes control to deal with the error signal depending on the state of the quick charging relay circuit 116Q when the error signal was output, etc.

[0062] Next, an example of the operation of the control unit 119 in this embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of the operation of the control unit 119 in this embodiment. This flow is started when the electric vehicle 100 is started or when the mode is changed. The battery management unit 117 determines whether or not a key-off operation has been performed based on information received from the higher-level vehicle control unit 118. The battery management unit 117 also determines whether or not the vehicle body is operating (key-on operation) based on information received from the higher-level vehicle control unit 118.

[0063] First, in step S110, the battery management unit 117 determines whether or not a key-off operation has been performed. If a key-off operation has been performed (step S110: YES), the process proceeds to step S120. If a key-off operation has not been performed (step S110: NO), the process returns to before step S110.

[0064] Next, in step S120, the battery management unit 117 determines whether or not the power extraction relay circuit 116T has a welding fault based on the detection result of the state of the power extraction relay circuit 116T. If the power extraction relay circuit 116T has a welding fault (step S120: YES), the process proceeds to step S130. If the power extraction relay circuit 116T does not have a welding fault (step S120: NO), the process proceeds to step S140.

[0065] In step S130, the battery management unit 117 stores the welding fault of the power extraction relay circuit 116T in, for example, an internal memory.

[0066] Next, in step S140, the battery management unit 117 determines whether or not the quick charging relay circuit 116Q has a welding fault based on the detection result of the state of the quick charging relay circuit 116Q. If the quick charging relay circuit 116Q has a welding fault (step S140: YES), the process proceeds to step S150. If the quick charging relay circuit 116Q does not have a welding fault (step S140: NO), the process proceeds to step S160.

[0067] In step S150, the battery management unit 117 stores the welding fault of the rapid charging relay circuit 116Q in, for example, an internal memory.

[0068] Next, in step S160, the battery management unit 117 determines whether or not the vehicle body 110 is operated (the key is turned on). If the vehicle body 110 is operated (step S160: YES), the process proceeds to step S170. If the vehicle body 110 is not operated (step S160: NO), the process returns to before step S160.

[0069] In step S170, the battery management unit 117 determines whether or not the welding fault information is stored in the internal memory. If the welding fault information is stored (step S170: YES), the process proceeds to step S180. If the welding fault information is not stored (step S170: NO), the process ends.

[0070] In step S180, the control unit 119 executes control to transmit the welding fault information via the CAN, and then this flow ends.

[0071] The electric vehicle 100 in the above embodiment is an electric vehicle having an attached object 150 that operates by electricity, and a vehicle body 110 on which the attached object 150 is mounted, and includes a battery 111 that supplies power to an electric motor 112 for operating the vehicle body 110, power supply lines 122L, 123L that supply power from the battery 111 to the attached object 150, power supply lines 121LQ, 122L that supply power from a quick charger 130Q to the battery 111, and a power supply line 122L. The vehicle body 110 includes a power extraction relay circuit 116T provided on the power supply lines 121L and 123L and capable of cutting off power, a quick charging relay circuit 116Q provided on the power supply lines 121LQ and 122L and capable of cutting off power, and a control unit 119 that determines whether or not the power extraction relay circuit 116T and the quick charging relay circuit 116Q have a welding failure and transmits the determination result to the CAN bus when the vehicle body 110 is next operated. This makes it possible to determine whether or not the mounted object 150 and the quick charger 130Q can be operated. As a result, the risk of electric shock to the user can be eliminated, thereby improving safety.

[0072] In the electric vehicle according to the above embodiment, the vehicle control unit 118 may execute control to transmit information indicating a welding fault in the power extraction relay circuit 116T and information indicating a welding fault in the quick charging relay circuit 116Q to a terminal device (such as a user's tablet terminal or smartphone) provided outside the vehicle body via a communication network. This makes it possible to protect the user and further improve safety.

[0073] In addition, in the electric vehicle according to the above embodiment, for example, the results of determining the states of the power extraction relay circuit 116T, the quick charging relay circuit 116Q, and the mounting relay circuit 156 may be notified to a user, etc., by display, sound, etc.

[0074] In this embodiment, the battery 111 may be charged by a commercial AC power source (not shown). In this case, a charger (not shown) provided inside the vehicle body 110 is electrically connected to the battery 111. The battery can be charged by electrically connecting a charging cable extending from the commercial AC power source to the charger.

[0075] In addition, the above-mentioned embodiments are merely examples of the embodiment of the present disclosure, and the technical scope of the present disclosure should not be interpreted as being limited by them. In other words, the present disclosure can be embodied in various forms without departing from the gist or main features thereof. [Industrial Applicability]

[0076] The present disclosure is suitably used for electric vehicles equipped with a power supply device for which improved safety is required. [Explanation of symbols]

[0077] 100 Electric Vehicles 110 Body 111 Battery 112 Electric motor 115 Communications Department 116Q Quick charge relay circuit 116T Power Extraction Relay Circuit 117 Battery management unit 118 Vehicle control unit 119 Control Unit 121LQ Power Supply Line 121C Connector 121CQ Connector 122L Power supply line 122LQ Power Supply Line 123L Power supply line 123C Connector 130Q quick charger 131Q Charging Cable 131C Connector 131CQ Connector 150 Bodywork 153C Connector 153L Power supply line 155 Communications Department 156 Bodywork relay circuit 157 Detection Unit 158 Control Unit

Claims

[Claim 1] An electric vehicle having an attachment that operates by electric power and a vehicle body on which the attachment is mounted, a battery for supplying power to an electric motor for operating the vehicle body; A first power supply line arranged on the vehicle body side for supplying power from the battery to the mounted object; A second power supply line arranged on the mounting side for supplying power from the battery to the mounting; a third power supply line for supplying power from a quick charger to the battery; a first protection circuit provided on the first power supply line and capable of cutting off power; a second protection circuit provided on the second power supply line and capable of cutting off power; a third protection circuit provided on the third power supply line and capable of cutting off power; A battery relay circuit is arranged between the battery and the first power supply line and is capable of cutting off power supplied from the battery to the mounted object; A control unit that controls a battery relay circuit to cut off power supplied from the battery to the mounted object when the first protection circuit has a welding failure and when the state of the second protection circuit has a welding failure; Equipped with When a key-off operation is performed and the control unit determines whether or not each of the first protection circuit and the third protection circuit has a welding fault, and when it is determined that at least one of the first protection circuit and the third protection circuit has a welding fault, stores information indicating the welding fault, and executes control to transmit the information indicating the welding fault onto a CAN bus when the vehicle body is next operated. Electric car.

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