vehicle

Abstract

The present invention provides a vehicle that can realize that the equipment using the battery power can continue to be used and the relay is protected even when the battery charging is started while the equipment is driven by the battery power. The vehicle comprises: a battery that stores power for driving; a power acquisition unit that acquires power for charging from the outside; a power supply function unit that can supply power from the battery to equipment other than the driving motor; a first relay that connects or disconnects the battery to or from the power line; a second relay that connects or disconnects the power acquisition unit to or from the power line; and a control unit that can execute a first switching control that switches the second relay to a connected state while keeping the first relay in a connected state. Furthermore, when the control unit switches the second relay to a connected state in the first switching control (step S13), the power input from the power acquisition unit is used to reduce the potential difference between the power acquisition unit side and the battery side of the second relay (step S8).

Description

Technical Field

[0001] The present invention relates to a vehicle including a battery for storing electric power for traveling and a power acquisition unit for acquiring electric power for charging the battery from the outside. Background Art

[0002] Vehicles such as EV (Electric Vehicle) and PHEV (Plug-in Hybrid Electric Vehicle) are equipped with large-capacity high-voltage batteries that store electricity for driving. High-voltage batteries are sometimes used as power sources for vehicle-mounted equipment such as air conditioners and navigation systems. In addition, in recent years, the convenience function of supplying AC power from sockets installed inside and outside the vehicle body has become practical, and high-voltage batteries can also be used as power sources for convenience functions.

[0003] Such vehicles can charge their high-voltage batteries by receiving power from an external power source. There are two types of charging: non-contact charging, which receives power from a power transmission coil of ground equipment, and wired charging, which receives power via a charging connector.

[0004] Generally, in a vehicle equipped with a high-voltage battery, in order to prevent the voltage of the high-voltage battery from being excessively output to the power line of the system, the power line can be disconnected from the high-voltage battery via a system main relay. In addition, in a vehicle capable of charging the high-voltage battery from an external power source, in order to prevent the voltage of the high-voltage battery from being unnecessarily output to the power acquisition unit, the voltage acquisition unit can be disconnected from the power line via a charging relay.

[0005] Patent Document 1 discloses an electric vehicle having a high voltage battery, a system main relay intermittently connecting the high voltage battery and a power line, a charger connected to an external power source to charge the high voltage battery, and an external charging relay intermittently connecting the charger and the high voltage battery.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2011 / 016134 Summary of the invention

[0009] Technical issues

[0010] In a vehicle with a high-voltage battery, in order to prevent excessive current such as inrush current from flowing to the relay, relay switching control is performed. For example, when the charging relay is switched to the connected state to start charging, the system main relay is temporarily switched to the disconnected state to disconnect the high-voltage battery from the power line, and then the charging relay is switched to the connected state. Then, the system main relay is switched to the connected state again. Since a protection mechanism is added to the system main relay to slowly change the voltage between its two ends, according to the above sequence, the high-voltage battery and the power acquisition unit can be connected via the power line without a large current flowing through the charging relay and the system main relay.

[0011] However, when charging the high voltage battery while operating an in-vehicle device or an electrical device connected to the outlet for a convenience function, if the switching control of the relay is performed as described above, there arises a problem that the power supply of the device is temporarily cut off.

[0012] An object of the present invention is to provide a vehicle that enables the equipment using the power of the battery to continue to be used and the relay to be protected even when charging of the battery is started while the equipment is driven by the power of the battery.

[0013] Technical Solution

[0014] The invention described in a first aspect provides a vehicle, characterized by comprising:

[0015] A battery that stores electricity for driving;

[0016] A power acquisition unit that acquires power for charging from the outside;

[0017] A power supply function unit capable of supplying power from the battery to devices other than the driving motor;

[0018] a first relay for connecting or disconnecting the battery from a power line;

[0019] a second relay that connects or disconnects the power acquisition unit and the power line; and

[0020] a control unit capable of executing a first switching control for switching the second relay to a connected state while keeping the first relay in a connected state,

[0021] When the control unit switches the second relay to the connection state by the first switching control, the control unit reduces a potential difference between the power acquisition unit side and the battery side of the second relay using the power input from the power acquisition unit.

[0022] The invention described in the second aspect is characterized in that, according to the vehicle described in the first aspect,

[0023] The control unit may further reduce a potential on the battery side of the second relay by increasing a load connected to the power line during the first switching control.

[0024] The invention according to the third aspect is characterized in that, according to the vehicle according to the second aspect,

[0025] The control unit switches between execution and non-execution of a process of lowering the potential on the battery side by increasing the load based on chargeable power of the battery.

[0026] The invention described in a fourth aspect is characterized in that, according to the vehicle described in any one of the first to third aspects,

[0027] The control unit measures a potential difference between the battery side and the power acquisition unit side of the second relay in the first switching control, and switches the second relay to a connection state when the measured potential difference is within a predetermined range.

[0028] The invention according to a fifth aspect is characterized in that, according to the vehicle according to any one of the first to fourth aspects,

[0029] Before switching the second relay to the connected state, the control unit determines whether the power supply function unit is in use. If it is in use, the second relay is switched by the first switching control. On the other hand, if it is not in use, the second relay is switched by other switching controls.

[0030] The invention according to a sixth aspect is characterized in that, according to the vehicle according to any one of the first to fifth aspects,

[0031] The power acquisition unit includes a power receiving coil that acquires power from a power transmission coil of an on-ground device in a non-contact manner.

[0032] The vehicle further includes a charging control unit, wherein the charging control unit makes a first excitation request to the ground device in order to determine whether the power transmission coil and the power receiving coil are aligned, wherein the first excitation request causes the power transmission coil to be excited at a lower level than when the charging power is transmitted.

[0033] The control unit issues a second excitation request to the ground equipment during the first switching control, wherein the second excitation request performs excitation at a higher level than the first excitation request and lower level than when the charging power is transmitted.

[0034] Effects of the Invention

[0035] According to the present invention, since the second relay is switched from the disconnected state to the connected state while the first relay is kept in the connected state by the first switching control, the power supply function part can be used continuously without interrupting the power supply to the device even if the battery charging starts during the use of the power supply function part. On the other hand, if the above switching of the first relay and the second relay is performed without any processing, a large current may flow to the second relay, but in the first switching control, when the second relay is switched, the power input from the power acquisition part is used to reduce the potential difference between the two ends of the second relay.

[0036] Thus, even if the second relay is connected with the battery connected to the power line, a large current can be suppressed from flowing to the second relay. Thus, even if the battery is charged during use of the power function unit, the device can be continuously used using the power function unit while protecting the second relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a block diagram showing a vehicle according to an embodiment of the present invention.

[0038] Figure 2 This is a flowchart showing the procedure of the non-contact charging transfer process executed by the charging control unit.

[0039] Figure 3 Yes means Figure 2 Flowchart of details of the voltage matching process of step S12.

[0040] Explanation of symbols

[0041] 1: Vehicle

[0042] 11: Battery

[0043] 12: Inverter

[0044] 13: Travel motor

[0045] 15: Vehicle Control Unit

[0046] 21: Inverter for air conditioner

[0047] 23: Car inverter

[0048] 24: In-car socket

[0049] 25: Power supply function unit

[0050] 31: Power receiving coil (power acquisition unit)

[0051] 32: Rectifier (power acquisition unit)

[0052] 34: Charging control unit

[0053] 36: Contactless charging transfer switch

[0054] Lb: Power line

[0055] Lc: Communication line

[0056] R1: System main relay (1st relay)

[0057] R2: Charging relay (second relay)

[0058] PC: Pre-charge unit

[0059] 100: Ground equipment

[0060] 103: Power transmission coil DETAILED DESCRIPTION

[0061] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 This is a block diagram showing a vehicle according to an embodiment of the present invention.

[0062] The vehicle 1 according to the embodiment of the present invention is an EV or HEV (Hybrid Electric Vehicle), etc., and includes a battery 11 for storing electric power for traveling, a travel motor 13 for driving driving wheels, and an inverter 12 for converting electric power between the battery 11 and the travel motor 13. The battery 11 outputs a high voltage for driving the travel motor 13, and can be called a high-voltage battery. The battery 11 is, for example, a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery.

[0063] The vehicle 1 also includes a system main relay R1, a pre-charging unit PC and a power line Lb. The battery 11 is connected to the power line Lb via the system main relay R1 and the pre-charging unit PC. The pre-charging unit PC has a function of slowly approaching the voltage between the two ends of the system main relay R1 when the system main relay R1 is in a disconnected state. In order to connect the battery 11 to the power line Lb, first, the pre-charging unit PC is switched to a connected state, thereby reducing the potential difference between the two ends of the system main relay R1. Thereafter, the system main relay R1 is switched to a connected state, and the pre-charging unit PC is switched to a disconnected state, thereby enabling the system main relay R1 to be switched from a disconnected state to a connected state without causing a large current to flow through the system main relay R1. Below, when explaining switching the system main relay R1 to a connected state, the above-mentioned switching action of the pre-charging unit PC is included. The system main relay R1 is equivalent to an example of the first relay of the present invention.

[0064] The vehicle 1 also includes a vehicle control unit 15 for controlling driving and various parts. The vehicle control unit 15 may be composed of one ECU (Electronic Control Unit) or a plurality of ECUs that operate in cooperation with each other. The vehicle control unit 15 drives the inverter 12, for example, according to the operation of the driving operation unit (pedals, shift levers, etc. not shown in the figure), so that the driving motor 13 performs power operation or regeneration operation. In this way, the vehicle 1 is driven in accordance with the driving operation. In addition, the vehicle control unit 15 performs startup control of the power supply function unit 25 and switching control of the system main relay R1 and the pre-charging unit PC.

[0065] The vehicle 1 also has a power supply function unit 25 that can use the power of the battery 11 to supply power supply voltage to electrical equipment other than the driving motor 13. The power supply function unit 25 includes an air-conditioning inverter 21 and a vehicle-mounted inverter 23. The air-conditioning inverter 21 converts the power of the battery 11 and transmits a driving current to the air conditioner 22 (compressor, etc.). The vehicle-mounted inverter 23 converts the power of the battery 11 into an AC power supply voltage and outputs it to the in-vehicle socket 24. By driving the vehicle-mounted inverter 23, the passengers of the vehicle 1 can connect household appliances, such as household appliances, to the socket for use. Although omitted from the figure, the vehicle 1 has a PTC (Positive Temperature Coefficient) heater as a load connected to the power line Lb. The PTC heater is a heater for heating the refrigerant for the air conditioner or the battery 11, and is connected to the power line Lb via a heater switch.

[0066] It should be noted that, in place of the in-vehicle socket 24 or in addition to the in-vehicle socket 24, an out-vehicle socket or an indoor socket that can use electrical appliances near the vehicle 1 (outside the vehicle compartment) can be connected to the in-vehicle inverter 23. Alternatively, the power supply function unit 25 can include a connector and a relay that can connect an external inverter instead of the in-vehicle inverter 23. In addition, it can also be configured such that: by connecting an external inverter to the connector, the relay is turned on, and thus, under the control of the vehicle control unit 15, power is supplied from the power line Lb to the inverter, and the AC power supply voltage is output from the external inverter to the out-vehicle socket. In addition, it can be configured such that the AC power supply voltage is output from the external inverter to the socket at home. The configuration of supplying the AC power supply voltage from the vehicle 1 to the outside of the vehicle is V2L (Vehicle to Load), and the configuration of supplying the AC power supply voltage from the vehicle 1 to the indoor is V2H (Vehicle to Home). With such a configuration, the user of the vehicle 1 can use electrical appliances near the vehicle 1 or at home using the power supplied from the vehicle 1.

[0067] The vehicle 1 further includes a non-contact charging mechanism 30 for contactlessly acquiring power from the ground equipment 100. The non-contact charging mechanism 30 includes a power receiving coil 31, a rectifier 32, a voltage sensor D1, a voltage sensor D2, a communication unit 33 for wireless communication, a charging control unit 34, and a charging relay R2. The power receiving coil 31 can receive power from the power transmitting coil 103 of the ground equipment 100 by electromagnetic coupling or electromagnetic resonance in a state of facing the power transmitting coil 103. The rectifier 32 rectifies the AC current output from the power receiving coil 31 and transmits it to the power line Lb side. The charging relay R2 switches the rectifier 32 and the power line Lb between a connected state and a disconnected state. The voltage sensors D1 and D2 detect the voltage on the power line Lb side of the charging relay R2 and the voltage on the rectifier 32 side, and transmit the detected values ​​to the charging control unit 34.

[0068] The charging control unit 34 is an ECU having a CPU (Central Processing Unit), a storage unit storing control programs and control data executed by the CPU, and a RAM (Random Access Memory) for CPU expansion data. The charging control unit 34 communicates with the ground equipment 100 via the communication unit 33, and receives voltage information from the rectifier 32 to control non-contact charging. The control of non-contact charging includes switching control of the charging relay R2. The charging control unit 34 communicates via the communication line Lc and cooperates with the vehicle control unit 15. That is, the charging control unit 34 can perform switching control of the system main relay R1 via the vehicle control unit 15.

[0069] The vehicle 1 further includes a non-contact charging transfer switch 36 provided on a dashboard or the like. The passenger of the vehicle 1 can send a command to the charging control unit 34 to transfer to non-contact charging by operating the non-contact charging transfer switch 36 .

[0070] It should be noted that since the vehicle control unit 15 and the charging control unit 34 cooperate with each other through communication via the communication line Lc, Figure 1 A part of the processing of the vehicle control unit 15 shown in the example (for example, the switching control of the system main relay R1) can be performed by the charging control unit 34. On the contrary, Figure 1 A part of the processing of the charging control unit 34 shown in the example (for example, the signal input from the contactless charging transfer switch 36, the switching control of the charging relay R2) can also be performed by the vehicle control unit 15. In addition, the vehicle control unit 15 and the charging control unit 34 can be integrated into a set of control units without having to be configured separately.

[0071] The ground equipment 100 includes a power transmission coil 103 for contactlessly transmitting electric power, an inverter 102 for converting electric power from an external power source and outputting the electric power to the power transmission coil 103, a communication unit 106 capable of communicating with the charging control unit 34 of the vehicle 1, and a ground equipment control unit 105 for driving and controlling the inverter 102. The charging control unit 34 of the vehicle 1 can send an excitation request for the power transmission coil 103 to the ground equipment control unit 105 via wireless communication performed by the communication units 33 and 106.

[0072] <Contactless charging transfer processing>

[0073] Next, the non-contact charging process for charging the battery 11 using the non-contact charging mechanism 30 will be described. The non-contact charging process includes a non-contact charging transfer process for transferring the state of the vehicle 1 to a state in which power can be transferred, and a power transfer process for transferring power contactlessly to actually charge the battery 11. When performing the non-contact charging process, the passengers of the vehicle 1 sometimes use the air conditioner 22 or any electrical equipment using the power function unit 25, and sometimes do not use the power function unit 25. During the use of electrical equipment, if the power function unit 25 stops and the electrical equipment in use stops, it will cause discomfort to the passengers.

[0074] Figure 2 This is a flowchart showing the procedure of the non-contact charging transfer process executed by the charging control unit. Figure 3 Yes means Figure 2 Flowchart of details of the voltage matching process of step S12.

[0075] The non-contact charging transfer process is started when the driver operates the non-contact charging transfer switch 36 when the vehicle 1 is located near the ground equipment 100. When the process is started, first, the charging control unit 34 communicates with the ground equipment control unit 105 via the communication unit 33, and requests the ground equipment control unit 105 for excitation for alignment (step S1). The excitation for alignment is an excitation for aligning the power receiving coil 31 with the power transmitting coil 103, and has a very small intensity compared to the excitation during charging. The request for excitation in step S1 is equivalent to an example of the first excitation request of the present invention.

[0076] If the excitation for alignment is performed based on the request of step S1, the charging control unit 34 performs the alignment process (step S2). In the alignment process, the charging control unit 34 monitors the induced electromotive force generated by the rectifier 32, and guides the driver to move the vehicle 1 or sends instructions to the automatic driving function, so as to position the receiving coil 31 at a position opposite to the transmission coil 103. If the vehicle 1 is stopped in a state where the receiving coil 31 generates an induced electromotive force of a predetermined size through the induction of the charging control unit 34, the charging control unit 34 communicates with the ground device control unit 105 via the communication unit 33, and requests the ground device control unit 105 to end the excitation (step S3). As a result, the excitation of the transmission coil 103 is temporarily ended.

[0077] Next, the charging control unit 34 accesses the vehicle control unit 15 to determine whether the power supply function unit 25 is in use (step S4). As a result, if the power supply function unit 25 is not in use, the charging control unit 34 connects the power receiving coil 31 and the rectifier 32 to the power line Lb through the usual relay switching process (steps S5 to S7). That is, the charging control unit 34 first switches the system main relay R1 to the disconnected state via the vehicle control unit 15 (step S5), and if the voltage of the power line Lb decreases, the charging relay R2 is connected (step S6). In addition, the charging control unit 34 switches the system main relay R1 to the connected state via the vehicle control unit 15 (step S7). In the switching of step S7, the function of the above-mentioned pre-charging unit PC is utilized to suppress excessive currents such as inrush current flowing into each part.

[0078] When the normal relay switching process of steps S5 to S7 is completed, the charging control unit 34 ends the non-contact charging transfer process and transfers the process to the power transmission process.

[0079] On the other hand, if the result of the determination in step S4 is that the power supply function unit 25 is in use, the charging control unit 34 connects the power receiving coil 31 and the rectifier 32 to the power supply line Lb through another type of relay switching process (steps S8 to S13). Hereinafter, the relay switching process of steps S8 to S13 is referred to as "the relay switching process of the first type". The relay switching process of the first type is equivalent to an example of the first switching control of the present invention.

[0080] In the relay switching process of the first mode, first, the charging control unit 34 requests the ground equipment control unit 105 for excitation for voltage matching through communication via the communication unit 33 (step S8). This excitation is larger than the excitation for alignment and smaller than the excitation during power transmission. The excitation is pre-set to a magnitude that causes the voltage on the rectifier 32 side of the charging relay R2 to rise to the same voltage as the power line Lb. Since the charging relay R2 is cut off, even if the excitation is smaller than the excitation during power transmission, the voltage on the rectifier 32 side of the charging relay R2 can be increased significantly.

[0081] Next, the charging control unit 34 cooperates with the vehicle control unit 15 to determine whether the output of the power supply function unit 25 is stable (step S9). When stable, the potential difference between the two ends of the charging relay R2 is measured based on the output of the voltage sensors D1 and D2 (step S10). Then, the charging control unit 34 determines whether the measured potential difference is within a predetermined range (step S11). Here, for the predetermined range, it is set to a voltage range that does not cause a large current to flow through the second relay R2 when the second relay R2 is switched to the connected state. Then, in the judgment of step S11, if it is determined that the potential difference is within the predetermined range, at this moment, the charging control unit 34 switches the charging relay R2 to the connected state (step S13).

[0082] On the other hand, in the determination process of step S11, if it is determined that the potential difference is not within the predetermined range, the charging control unit 34 performs the voltage matching process of step S12 (step S12). Figure 3 As shown, in the voltage matching process, first, the charging control unit 34 determines whether the voltage on the rectifier 32 side is low (step S21). If not, it requests the ground device control unit 105 to reduce the excitation of the power transmission coil 103 through communication via the communication unit 33 (step S23). Here, the charging control unit 34 can request to reduce the amount of a predetermined section, or it can request to reduce the amount corresponding to the potential difference compared in step S21 to eliminate the potential difference. In step S23, if the excitation reduction is requested, the charging control unit 34 ends the voltage matching process and returns the process to the non-contact charging transfer process ( Figure 2 ) in step S9.

[0083] On the other hand, if it is determined in step S21 that the voltage on the rectifier 32 side is low, the charging control unit 34 determines whether the rechargeable power Win of the battery 11 is below a preset threshold value (step S22). The information of the rechargeable power Win is calculated and maintained by the management unit (battery control unit) of the battery 11 (not shown) based on various state information such as the temperature and voltage of the battery 11. The charging control unit 34 can obtain the rechargeable power Win from the management unit of the battery 11 via the communication line Lc. The rechargeable power Win refers to the limit value of the charging power that can flow in the battery 11. For example, when the battery 11 is cold or the charging rate is high, the rechargeable power Win becomes smaller. When the rechargeable power Win is small, if the charging relay R2 is connected when the voltage on the rectifier 32 side is high, there is a possibility that the power transmitted from the non-contact charging mechanism 30 to the battery 11 exceeds the rechargeable power Win. Therefore, it is preferable not to increase the voltage on the rectifier 32 side.

[0084] If the result of the judgment in step S22 is that the chargeable power Win is greater than the threshold value, the charging control unit 34 requests the ground device control unit 105 to increase the excitation of the power transmission coil 103 through the communication via the communication unit 33 (step S24). Here, the charging control unit 34 may request to increase the amount by a predetermined amount, or may request to increase the amount corresponding to the potential difference compared in step S21 to eliminate the potential difference. In step S24, if the request to increase the excitation is made, the charging control unit 34 ends the voltage matching process and returns the process to the non-contact charging transfer process ( Figure 2 ) in step S9.

[0085] On the other hand, if the result of the judgment in step S22 is that the chargeable power Win is below the threshold value, the charging control unit 34 increases the load connected to the power line Lb (step S25) according to the request to the vehicle control unit 15, for example, by driving the heater, disconnecting the drive wheel and driving only the travel motor 13, or increasing the driving amount of the air conditioner 22. In this way, the voltage on the power line Lb side of the charging relay R2 can be reduced, and the potential difference between the two ends of the charging relay R2 can be reduced. In step S25, if the load is increased, the charging control unit 34 ends the voltage matching process and returns the process to the non-contact charging transfer process ( Figure 2 ) in step S9.

[0086] By the voltage matching process as described above, even when the potential difference between the two ends of the charging relay R2 is greater than a predetermined range, the potential difference can be reduced. Figure 2), by repeating the loop processing of steps S9 to S12, the potential difference between the two ends of the charging relay R2 is reduced to a predetermined range. In this state, the charging relay R2 can be switched to a connected state in a manner that does not cause a large current to flow through the charging relay R2.

[0087] When the non-contact charging transfer process is completed, the charging control unit 34 transfers the process to the power transmission process, and excites the power transmission coil 103 for power transmission. Through this excitation, the charging current is transmitted to the battery 11 via the power receiving coil 31, the rectifier 32, the charging relay R2 and the system main relay R1. In addition, even if the electrical device is being used while receiving power from the power supply function unit 25 before charging, the electrical device can be used continuously without interrupting the power supply.

[0088] As described above, according to the vehicle 1 of the present embodiment, the charging control unit 34 can perform the relay switching process ( Figure 2 In steps S8 to S13), the charging relay R2 is switched to a connected state while the system main relay R1 remains in a connected state. In addition, in the relay switching process of the first mode (steps S8 to S13), the charging control unit 34 uses the power obtained from the ground equipment 100 to reduce the potential difference between the power line Lb side of the charging relay R2 and the rectifier 32 side. And, in a state where the potential difference is reduced, the charging relay R2 is switched to a connected state. Therefore, even in the case where charging is started during the use of the power supply function unit 25, the charging of the battery 11 can be started without interrupting the power supply of the power supply function unit 25. In addition, when the state of the charging relay R2 is switched, the charging relay R2 can be protected in a manner that prevents a large current from flowing through the charging relay R2.

[0089] When the battery 11 is charged in a non-contact charging mode, the driver or passengers often stay in the vehicle when charging starts, and often use electrical equipment with the power of the power supply function unit 25 when charging the battery 11 starts. Therefore, the relay switching process of the first mode described above is more effective in starting non-contact charging without temporarily stopping the power supply function unit 25.

[0090] In addition, according to the relay switching process (steps S8 to S13) of the first mode, since the disconnection of the system main relay R1 and the pre-charging operation by the pre-charging unit PC are not required, the charging relay R2 can be connected in a short time compared to the existing relay switching method, so that the system can be transferred to a state where charging is possible. In addition, since the operation of the system main relay R1 and the pre-charging unit PC is not required, the time-dependent degradation of the system main relay R1 and the pre-charging unit PC can be reduced.

[0091] Furthermore, according to the vehicle 1 of the present embodiment, when performing the voltage matching process ( Figure 3 ), the charging control unit 34 increases the load connected to the power line Lb, thereby reducing the potential difference between the two ends of the charging relay R2 (step S25). By combining these processes, even if it is not desired to excessively increase the voltage on the rectifier 32 side, the potential on the power line Lb side can be reduced, thereby reducing the potential difference between the two ends of the charging relay R2.

[0092] According to the vehicle 1 of the present embodiment, the charging control unit 34 switches between execution and non-execution of control of increasing and decreasing the load connected to the power line Lb based on the chargeable power Win of the battery 11 ( Figure 3 Therefore, when the chargeable power Win of the battery 11 is small, the voltage on the power line Lb side can be lowered, the potential difference between the two ends of the charging relay R2 can be reduced, and a large charging current flowing into the battery 11 can be suppressed.

[0093] Furthermore, according to the vehicle 1 of the present embodiment, the charging control unit 34 determines whether the power supply function unit 25 is in use ( Figure 2 Step S4 of the embodiment). Furthermore, when in use, the charging relay R2 is switched to the connected state while the system main relay R1 is kept connected according to the relay switching process of the first embodiment (steps S8 to S13). On the other hand, if the power supply function unit 25 is not in use, the relay switching process of the normal embodiment (steps S5 to S7) is performed. Therefore, in the case where the system main relay R1 can be disconnected, the voltage matching process can be omitted.

[0094] In addition, according to the vehicle 1 of the present embodiment, the charging control unit 34 makes an excitation request (step S8) to the ground equipment 100 that is smaller than that during power transmission and larger than that during alignment in the relay switching process (steps S8 to S13) of the first mode. As a result, when performing contactless charging, the potential on the rectifier 32 side of the second relay R2 can be increased, and the potential difference between the two ends of the second relay R2 can be reduced. The excitation request of step S8 is equivalent to an example of the second excitation request of the present invention.

[0095] The above is a description of the embodiment of the present invention. However, the present invention is not limited to the above embodiment. For example, sometimes a vehicle includes a power supply function unit such as an air-conditioning inverter and a heater switch that allow power supply interruption, and a power supply function unit that has the possibility of connecting a device such as a vehicle-mounted inverter that does not allow power supply interruption. In the above embodiment, the air-conditioning inverter, the vehicle-mounted inverter, and the heater switch are all regarded as the power supply function unit of the present invention, and the structure of selecting the first mode of relay switching processing (steps S8 to S13) as long as one of them is in use is shown. However, only a specific part of these power supply function units, such as a specific part of the power supply function unit that is generated when the power supply interruption is not allowed, can be regarded as the power supply function unit of the present invention. And, when a specific part of the power supply function unit is in use, the first mode of relay switching processing (steps S8 to S13) can be selected; when a specific part of the power supply function unit is not in use, the normal mode of relay switching processing (steps S5 to S7) can be selected.

[0096] In addition, in the above-mentioned embodiment, in order to measure the potential difference between the two ends of the charging relay R2, a configuration is shown in which dedicated voltage sensors D1 and D2 are provided, but, for example, a voltage sensor in the inverter 12 or a voltage sensor of the battery 11 may be used instead of the voltage sensor D1. In addition, the voltage sensor D2 may be provided in the rectifier 32 or in the power receiving coil 31, and a configuration in which the voltage on the rectifier 32 side is estimated based on the strength information of the excitation of the power transmission coil, etc. may be used instead of the voltage sensor D2.

[0097] In addition, the control processing shown in the above embodiment, for example, Figure 2 In steps S4 to S7, the relay switching process of the first mode is performed regardless of whether the power supply function unit is used or not. In addition, in the relay switching process of the first mode, the process of confirming and adjusting the potential difference in steps S9 to S12 can be omitted, and the control of reducing the potential difference between the two ends of the charging relay can be completed only by excitation for voltage matching. In addition, in the voltage matching process, steps S22 and S25 can be omitted, and voltage matching can be performed only by increasing or decreasing excitation.

[0098] In addition, in the above-mentioned embodiment, as the power acquisition unit of the present invention, a structure for non-contact power transmission is shown as an example. However, as the power acquisition unit of the present invention, a structure for transmitting power from an external power source through a wired connection can also be used. For example, in a vehicle that charges a battery by acquiring a DC power supply voltage from the outside, as a power acquisition unit that receives the DC power supply voltage, a power receiving coil and a rectifier in a non-contact charging mechanism are used to convert into a wired power line, and a communication unit is converted into a wired structure, and other components are almost the same as the non-contact charging mechanism. Therefore, even in a vehicle that charges a battery from a DC power supply through a wired connection, the present invention can be applied using the same structure and control method as the embodiment. In addition, the details shown in the embodiment can be appropriately changed without departing from the main purpose of the invention.

Claims

1. A vehicle, characterized in that: have: A battery that stores electricity for driving; A power acquisition unit that acquires power for charging from the outside; a power supply function unit capable of supplying power from the battery to devices other than the travel motor; a first relay, which connects or disconnects the battery to a power line; a second relay that connects or disconnects the power acquisition unit and the power line; and a control unit capable of executing a first switching control for switching the second relay to a connected state while keeping the first relay in a connected state, When the control unit switches the second relay to the connected state by the first switching control, the control unit reduces the potential difference between the power acquisition unit side and the battery side of the second relay using the power input from the power acquisition unit, The control unit further reduces the potential of the battery side of the second relay by increasing a load connected to the power line during the first switching control. The control unit switches between execution and non-execution of a process of lowering the potential on the battery side by increasing the load based on the chargeable power of the battery.

2. The vehicle according to claim 1, characterized in that The control unit measures a potential difference between the battery side and the power acquisition unit side of the second relay in the first switching control, and switches the second relay to a connection state when the measured potential difference is within a predetermined range.

3. The vehicle according to claim 1 or 2, characterized in that: Before switching the second relay to the connected state, the control unit determines whether the power supply function unit is in use, and if in use, switches the second relay through the first switching control, and on the other hand, if not in use, switches the second relay through other switching controls.

4. The vehicle according to claim 1 or 2, characterized in that: The power acquisition unit includes a power receiving coil that acquires power from a power transmission coil of the ground equipment in a non-contact manner. The vehicle further includes a charging control unit, wherein the charging control unit makes a first excitation request to the ground device in order to determine whether the power transmission coil and the power reception coil are aligned, wherein the first excitation request causes the power transmission coil to be excited at a lower level than when the charging power is transmitted. The control unit issues a second excitation request to the ground equipment during the first switching control, wherein the second excitation request performs excitation at a higher level than the first excitation request and lower level than when the charging power is transmitted.

5. The vehicle according to claim 3, characterized in that The power acquisition unit includes a power receiving coil that acquires power from a power transmission coil of the ground equipment in a non-contact manner. The vehicle further includes a charging control unit, wherein the charging control unit makes a first excitation request to the ground device in order to determine whether the power transmission coil and the power reception coil are aligned, wherein the first excitation request causes the power transmission coil to be excited at a lower level than when the charging power is transmitted. The control unit issues a second excitation request to the ground equipment during the first switching control, wherein the second excitation request performs excitation at a higher level than the first excitation request and lower level than when the charging power is transmitted.

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