Charging system for vehicle, charging circuit, charging device, and voltage control method

Abstract

A charging system for a vehicle, a charging circuit, a charging device, and a voltage control method are provided. When the voltage supplied to the first connector (111) is a DC voltage and when the voltage of the battery (106) is higher than a predetermined value, the ECU (320) applies the DC voltage from the pair of first power lines (350) to the auxiliary machine DDC (200) by closing the first switching device (301). Furthermore, when the voltage supplied to the first connector (111) is a DC voltage and when the voltage of the battery (106) is lower than a predetermined value, the ECU (320) opens the first switching device (301) and operates at least one of the PFC (154) and the insulated DC-DC converter (170), thereby applying the DC voltage transformed by the charging circuit (180) to the auxiliary machine group (108).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a charging system for a vehicle, a charging circuit, a charging device, and a voltage control method. BACKGROUND

[0002] Japanese Patent Application Publication No. 2021-141545 discloses a power supply system for an electric vehicle. In the power supply system, a direct-current voltage is supplied from an external charger provided at a charging station to an electric vehicle to charge a battery. Specifically, the power supply system has an inlet for a DC power supply, and charges the battery with a direct-current voltage corresponding to the state of the battery supplied from the external charger. In a case where the charge amount of the battery is low and the battery voltage is lower than usual, the supplied direct-current voltage also becomes low. This charging is also referred to as fast charging.

[0003] Further, Japanese Patent Application Publication No. 2023-047162 discloses a technology that switches the connection of battery cells that constitute a battery between series connection / parallel connection depending on the charge and discharge state of the battery.

[0004] Generally, an electric vehicle has a DCDC converter for auxiliary machines that steps down the battery voltage of 400 V, for example, to 14 V to supply power to the auxiliary machine group in order to operate the auxiliary machine group of the vehicle. The auxiliary machine group also includes an ECU (Electronic Control Unit) used in vehicle control and a charging relay, an air conditioning device, a battery temperature regulating device, and a sound equipment, and the like. It is desirable that these devices included in the auxiliary machine group also operate during charging of the battery. In other words, in an electric vehicle, it is preferable that stable power be supplied to the auxiliary machine group even during charging of the battery.

[0005] However, there are cases where stable power cannot be supplied to the auxiliary machine group due to voltage fluctuation of the battery at the time of charging. Such cases include a first case and a second case. The first case is a case where the direct-current voltage supplied from the charger is low due to the charge amount of the battery being low and the battery voltage being lower than usual. Further, the second case is a case where the connection of battery cells that constitute a battery is switched between series connection and parallel connection depending on the charge and discharge state of the battery. SUMMARY

[0006] The present disclosure was completed to solve the above-described problems, and an object of an aspect is to supply stable power to an auxiliary machine group regardless of the voltage of a battery during charging of the battery.

[0007] A charging system for a vehicle according to the present disclosure is mounted on a vehicle. The charging system includes a battery that stores electric power used to generate driving force of the vehicle, a first connector that is supplied with at least a direct-current voltage from an external charger, and a pair of first power lines that link the battery and the first connector. The charging system also includes a charging circuit that charges the battery by converting an alternating-current voltage supplied from the external charger into a direct-current voltage and outputting the direct-current voltage to the pair of first power lines, an auxiliary machine DC-DC converter that converts a voltage of the battery input from the pair of first power lines and supplies the converted voltage to an auxiliary machine group including at least an auxiliary machine, a first switching device that is disposed between the pair of first power lines and an output side of the charging circuit and an input side of the auxiliary machine DC-DC converter, and a control circuit. The charging circuit includes a power factor improvement circuit and a charging DC-DC converter that steps up a direct-current voltage output from the power factor improvement circuit. When a predetermined condition related to charging of the battery is satisfied, the control circuit cuts off the pair of first power lines from the output side of the charging circuit and the input side of the auxiliary machine DC-DC converter by opening the first switching device, and supplies a direct-current voltage supplied to the first connector to the charging circuit and operates at least one of the power factor improvement circuit and the charging DC-DC converter, thereby supplying the direct-current voltage stepped up by the charging circuit to the auxiliary machine group.

[0008] A charging circuit according to the present disclosure is a charging circuit mounted on a vehicle and charging a battery, the vehicle including the battery that stores electric power used to generate driving force of the vehicle. The vehicle includes a first connector that is supplied with at least a direct-current voltage from an external charger, a pair of first power lines that link the battery and the first connector, an auxiliary machine DC-DC converter that converts a voltage of the battery input from the pair of first power lines and supplies the converted voltage to an auxiliary machine group including at least an auxiliary machine, and a first switching device that is disposed between the pair of first power lines and an output side of the charging circuit and an input side of the auxiliary machine DC-DC converter. The charging circuit includes a power factor improvement circuit and a charging DC-DC converter that steps up a direct-current voltage output from the power factor improvement circuit. The charging circuit charges the battery by converting an alternating-current voltage supplied from the external charger into a direct-current voltage and outputting the direct-current voltage to the pair of first power lines. When a predetermined condition related to charging of the battery is satisfied, the first switching device is opened, thereby cutting off the pair of first power lines from the output side of the charging circuit and the input side of the auxiliary machine DC-DC converter, and a direct-current voltage supplied to the first connector is supplied to the charging circuit and at least one of the power factor improvement circuit and the charging DC-DC converter is operated, thereby supplying the direct-current voltage stepped up by the charging circuit to the auxiliary machine group.

[0009] The control method of the present disclosure is a control method of voltage in a vehicle. The vehicle is provided with: a battery that stores electric power used to generate a driving force of the vehicle; a first connector that is supplied with at least a direct-current voltage from an external charger; a pair of first power lines that link the battery and the first connection connector; a charging circuit that charges the battery by converting an alternating-current voltage supplied from the external charger into a direct-current voltage and outputting the direct-current voltage to the pair of first power lines; an auxiliary machine DCDC converter that converts a voltage of the battery input from the pair of first power lines and supplies the converted voltage to an auxiliary machine group including at least an auxiliary machine; and a first switching device that is arranged between the pair of first power lines and an output side of the charging circuit, and an input side of the auxiliary machine DCDC converter. The charging circuit is provided with a power factor improvement circuit and a charging DCDC converter that steps up a direct-current voltage output from the power factor improvement circuit. The control method is provided with a step of, when a predetermined condition related to charging of the battery is satisfied, opening the first switching device to thereby cut off the pair of first power lines from the output side of the charging circuit and the input side of the auxiliary machine DCDC converter, and supply a direct-current voltage supplied to the first connector to the charging circuit and operate at least one of the power factor improvement circuit and the charging DCDC converter, whereby the direct-current voltage stepped up by the charging circuit is supplied to the auxiliary machine group.

[0010] The above and other objects, features, aspects and advantages of the present application will become more apparent from the following detailed description of the present application when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a block diagram showing the structure of a vehicle.

[0012] Figure 2 is a block diagram of a charging system of the first embodiment.

[0013] Figure 3 is a flowchart of a process performed by an ECU of the first embodiment.

[0014] Figure 4 is a block diagram of a charging system of the second embodiment.

[0015] Figure 5 is a flowchart of a process performed by an ECU of the second embodiment.

[0016] Figure 6 is a block diagram of a charging system of the third embodiment.

[0017] Figure 7 is a block diagram of a charging system of the fourth embodiment.

[0018] Figure 8 is a block diagram of a charging system of the fifth embodiment.

[0019] Figure 9 is a block diagram of a charging system of the 6th embodiment.

[0020] Figure 10 is a block diagram of another charging system of the 6th embodiment.

[0021] Figure 11 is a block diagram of a charging system of the 7th embodiment.

[0022] Figure 12 is a block diagram of another charging system of the 7th embodiment.

[0023] Figure 13 is a block diagram of another charging system of the 7th embodiment. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present disclosure will be explained in detail with reference to the attached drawings. In addition, the same or equivalent portions will be denoted by the same reference numerals, and their explanations will not be repeated.

[0025] <1st Embodiment>

[0026] [Charging System]

[0027] Figure 1 is a block diagram showing the structure of a vehicle. The charging system 100 of the present embodiment is mounted on a vehicle 1000. The vehicle 1000 is an electric vehicle. In this way, the charging system 100 is a charging system for the vehicle 1000.

[0028] Figure 2 is a block diagram of the charging system 100 of the present embodiment. The charging system 100 is provided with an ECU 320, a 1st connector 111, a pair of 1st power lines 350, an electrical load 104, a battery 106, a charging device 300, an auxiliary machine group 108, an in-vehicle power supply connector 110, and a sensor 107. The pair of 1st power lines 350 corresponds to the "pair of 1st power lines" of the present disclosure.

[0029] The 1st connector 111 is inserted with, for example, a charger 113 provided at a charging station, and is applied with an AC (Alternating Current) voltage or a DC (Direct Current) voltage from the charger 113. The ECU 320 can determine which one of the AC voltage and the DC voltage is supplied from the 1st connector 111. For example, the charger 113 transmits a voltage kind signal showing which one of the AC voltage and the DC voltage to the ECU 320. The ECU 320 can determine which one of the AC voltage and the DC voltage is charged based on the voltage kind signal.

[0030] The battery 106 is a high-voltage battery, for example, a 400 V battery. Further, the sensor 107 detects the voltage of the battery 106. The sensor 107 detects, for example, the SOC (State Of Charge) of the battery 106 or the like.

[0031] The charging device 300 is provided with a charging circuit 180, a DCF (Direct Current Filter) 190, and an auxiliary machine DDC 200. Typically, the charging circuit 180 is an on-board charger. The charging circuit 180 converts the alternating voltage supplied to the first connector 111 into direct current voltage to charge the battery 106. The auxiliary machine DDC 200 corresponds to the "auxiliary machine DCDC converter" of the present disclosure.

[0032] The charging circuit 180 has an OBC ACF (On-Board Charger Alternating Current Filter) 152, a PFC (Power Factor Correction) 154, and an insulation type DCDC converter 170. The insulation type DCDC converter 170 includes a primary (Pri; same below) circuit 156, a transformer 158, and a secondary (sec; same below) circuit 160. The insulation type DCDC converter 170 corresponds to the "charging DCDC converter" of the present disclosure.

[0033] The OBC ACF 152 suppresses noise sent to the commercial AC line (first connector 111) and noise input to the charging circuit 180. The PFC 154 improves the power factor of the AC power supplied from the OBC ACF 152. The PFC 154 corresponds to the "power factor improvement circuit" of the present disclosure. Also, the PFC 154 converts the AC voltage of the AC power after the power factor improvement into a DC voltage (rectification). The insulation type DCDC converter 170 performs voltage conversion on the DC voltage supplied from the PFC 254. In the present embodiment, the voltage conversion is "step-up".

[0034] In addition, the charging circuit 180 can perform bidirectional operation. The insulation type DCDC converter 170 of the charging circuit 180 performs voltage conversion on the direct current voltage supplied from the battery 106, and the PFC 154 converts the direct current voltage into alternating current voltage (performs DC / AC conversion operation) to supply power to the in-vehicle power supply connector 110. The supplied voltage is, for example, AC 100 V for household use.

[0035] The DCF 190 is a filter that suppresses noise of the voltage supplied to the battery 106 and noise of the voltage supplied from the battery 106.

[0036] The auxiliary machine DDC 200 supplies electric power to the auxiliary machine group 108. The auxiliary machine group 108 includes at least an auxiliary machine. The auxiliary machine includes, for example, the ECU 320, a plurality of switching devices described later, a temperature adjustment device (not shown) that adjusts the temperature of the battery 106, an in-vehicle air conditioner (not shown), and the like. Further, the auxiliary machine group can include an auxiliary machine battery for the auxiliary machine.

[0037] The auxiliary machine DDC 200 includes an isolated DCDC converter 210 and a DDC-F (Filter of the auxiliary machine DDC 200) 212. The isolated DCDC converter 210 includes a primary circuit 202, a transformer 204, and a secondary circuit 206.

[0038] A pair of the first power lines 350 is a power line that links the first connector 111 and the battery 106. In other words, one end of the pair of the first power lines 350 is connected to the first connector 111, and the other end of the pair of the first power lines 350 is connected to the battery 106. For the pair of the first power lines 350, a high-voltage power line 350H through which a high-voltage current flows and a low-voltage power line 350L through which a low-voltage current flows are paired.

[0039] The first node 102A, the second node 102B, and the third node 102C are provided at the pair of the first power lines 350. The second node 102B is provided at a position closer to the battery 106 than the first node 102A. The third node 102C is provided at a position closer to the battery 106 than the second node 102B.

[0040] At the first node 102A, a power line is branched from the pair of the first power lines 350. The branched power line is connected to an OBCACF (On-Board Charger Alternating Current Filter) 152 included in the charging circuit 180.

[0041] At the second node 102B, a power line is branched from the pair of the first power lines 350. The branched power line is connected to the electric load 104. The electric load 104 is a load that generates driving force of the vehicle 1000 by electric power of the battery 106. The electric load 104 is, for example, a traction inverter.

[0042] At the third node 102C, a power line is branched from the pair of the first power lines 350. The branched power line 351 is connected to a DCF (Direct Current Filter) 190 included in the charging device 300. In addition, although not shown, the power line 351 is connected to both the charging circuit 180 and the auxiliary machine DDC 200 inside the DCF 190.

[0043] The charging system 100 also has a plurality of switching devices. The plurality of switching devices includes a first switching device 301, a second switching device 302, and a third switching device 303. One switching device includes a high-voltage side relay provided on a high-voltage side power line and a low-voltage side relay provided on a low-voltage side power line. For example, the first switching device 301 includes a high-voltage side relay 301H and a low-voltage side relay 301L. The first switching device 301 is arranged between a pair of first power lines 350 and an output side (secondary circuit 160) of the charging circuit 180, an input side (primary circuit 202) of the auxiliary machine DDC 200.

[0044] Further, in the present disclosure, "opening a switching device" means "opening both the high-voltage side relay and the low-voltage side relay included in the switching device". By opening the switching device, electricity becomes non-conductive (cannot be conducted) at the position of the switching device. On the other hand, "closing a switching device" means "closing both the high-voltage side relay and the low-voltage side relay included in the switching device". By closing the switching device, electricity becomes conductive (can be conducted) at the position of the switching device.

[0045] In addition, the third switching device 303 includes a relay 303P connected to a resistor in addition to the relay 303H and the relay 303L. For example, the charging system 100 closes the relay 303H and the relay 303P when pre-charging a capacitor of the electrical load 104 at the time of starting the vehicle 1000. Thereby, the current flowing can be reduced in correspondence with the resistor connected to the relay 303P, and thus, the rush current flowing to the capacitor can be suppressed.

[0046] The ECU 320 performs control of charging by the external power source, control of switching of the plurality of switching devices, control of the charging device 300, and the like. The ECU 320 corresponds to the "control circuit" of the present disclosure.

[0047] [Control of ECU 320]

[0048] Next, the control of the ECU 320 will be described. The ECU 320 performs control of switching of the plurality of switching devices and control of the charging device 300. Thereby, the state of the vehicle 1000 (the charging system 100) can be switched to any one of a plurality of states. The plurality of states include a battery discharge state, an AC charging state, and a DC charging state.

[0049] First, the battery discharge state will be described. The battery discharge state is a state in which the battery 106 is discharged, and is, for example, a state in which the vehicle 1000 is driven (driven). The ECU 320 closes the first switching device 301, opens the second switching device 302, and closes the third switching device 303, thereby making the state of the charging system 100 the battery discharge state.

[0050] In the battery discharge state, electric power from the battery 106 is applied to the electrical load 104 and the DCF 190. Also, electric power is applied from the DCF 190 to the charging circuit 180 and the auxiliary machine DDC 200. Electric power from the charging circuit 180 is applied to the in-vehicle power supply connector 110 through the reverse action of the insulation type DCDC converter 170 and the above-described DC / AC conversion action of the PFC 154. The voltage applied to the in-vehicle power supply connector 110 is, for example, AC 100 V of a household. Also, electric power from the auxiliary machine DDC 200 is applied to the auxiliary machine group 108.

[0051] Next, the AC charging state will be described. The AC charging state is a state in which the battery 106 is charged by being supplied with an AC voltage from the first connector 111. The ECU 320 opens the second switch device 302 and closes the first switch device 301 and the third switch device 303 if it determines that an AC voltage is applied from the charger 113.

[0052] In addition, either the second switch device 302 or the third switch device 303 can be open. However, if both the second switch device 302 and the third switch device 303 are open, it is possible to prevent a situation in which electric power is accidentally supplied to the electrical load 104.

[0053] In the AC charging state, the AC electric power supplied from the first connector is applied to the OBC ACF 152. The OBC ACF 152 suppresses noise input to the charging circuit 180.

[0054] The PFC 154 improves the power factor of the AC electric power supplied from the OBC ACF 152. Also, the PFC 154 converts the AC voltage of the AC electric power after the improvement of the power factor into a DC voltage (rectification). The insulation type DCDC converter 170 steps up the DC voltage supplied from the PFC 154.

[0055] The DCF 190 suppresses noise of the voltage supplied from the insulation type DCDC converter 170. The voltage from the DCF 190 is applied to the auxiliary machine DDC 200 and the battery 106. Thereby, electric power from the DCF 190 is supplied to the auxiliary machine DDC 200 and the battery 106. The auxiliary machine DDC 200 supplies electric power from the charging circuit 180 (insulation type DCDC converter 170) or the battery 106 to the auxiliary machine group 108 (auxiliary machines, auxiliary battery). The auxiliary battery is charged by the supplied electric power.

[0056] Next, the DC charging (quick charging) state will be described. The ECU 320 acquires the voltage of the battery 106 before DC charging, which is detected by the sensor 107, in a case where DC charging is performed. Also, the ECU 320 transmits a request signal to the charger 113. The request signal is a signal for requesting the charger 113 to start charging of the battery 106 at a start time voltage. The start time voltage is the voltage from a time point at which charging by the charger 113 is started to a time point at which a predetermined short time (for example, 3 seconds) elapses. The start time voltage is also referred to as a start voltage.

[0057] Specifically, in a case where the voltage detected by the sensor 107 (the voltage of the battery 106 before charging) is a predetermined value or more, the ECU 320 transmits a request signal for requesting a higher voltage, which is the voltage at the start of charging, to the charger 113. The predetermined value is a value decided in advance.

[0058] Also, the ECU 320 closes the first switching device 301, the second switching device 302, and the third switching device 303, and does not cause the charging circuit 180 to perform a charging operation. Thereby, a sufficient voltage is supplied from the charger 113 to the battery 106. In addition, the potential of the third node 102C becomes a high potential. Therefore, the current flowing in the pair of first power lines 350 is branched at the third node 102C, and the branched current can be supplied to the charging device 300 via the pair of power lines 351. The charging device 300 can cause the current to flow to the in-vehicle power supply connector 110 and the auxiliary machine group 108. Thereby, the ECU 320 can supply stable electric power to the in-vehicle power supply connector 110 and the auxiliary machine group 108.

[0059] On the other hand, there is a case where the voltage detected by the sensor 107 is lower than the predetermined value (a case where the electric power of the battery 106 is depleted). In this case, there is a tendency that excessive current flows from the charger 113 to the battery 106 at the start of DC charging with the same voltage as in a case where the voltage detected by the sensor 107 is the predetermined value or more. In this case, in a case where a higher voltage is supplied from the charger 113 to the battery 106, there is a case where damage to the battery 106 or the like occurs.

[0060] Therefore, in order to suppress damage to the battery 106 or the like, in a case where the voltage of the battery 106 before charging is lower than the predetermined value described above, the ECU 320 transmits a request signal for requesting a lower voltage, which is a voltage higher than the voltage of the battery 106 before charging, to the charger 113.

[0061] In other words, the start voltage requested by the request signal in the case where the voltage of the battery 106 is lower than the predetermined value is lower than the start voltage requested by the request signal in the case where the voltage of the battery 106 is higher than the predetermined value. Hereinafter, the control of changing the level of the start voltage depending on the level of the voltage of the battery 106 before charging is also referred to as "voltage control".

[0062] However, in the case where a lower voltage is requested from the charger 113, on the one hand, damage to the battery 106 and the like can be suppressed, and on the other hand, sufficient electric power cannot be supplied to the auxiliary machine DDC 200. As described above, the auxiliary machine DDC 200 supplies electric power to the auxiliary machine group 108, the ECU 320, the first switching device 301, the second switching device 302, and the third switching device 303, and the like. Therefore, there is a case where, in the case where the start voltage from the charger 113 is low, the auxiliary machine DDC 200 cannot supply sufficient electric power to the auxiliary machine group 108, the ECU 320, the first switching device 301, the second switching device 302, and the third switching device 303, and the like during DC charging of the battery 106.

[0063] Therefore, in the present embodiment, in the case where the voltage detected by the sensor 107 is lower than the predetermined value, the ECU 320 steps up the lower voltage from the charger 113 at the charging circuit 180 and supplies it to the auxiliary machine DDC 200. Specifically, the ECU 320 opens the first switching device 301 and closes the second switching device 302 and the third switching device 303. Also, the ECU 320 operates the charging circuit 180.

[0064] By this, the current from the charger 113 flows to the OBC ACF 152. Therefore, the DC voltage supplied from the first connector 111 is applied to the OBC ACF 152. The OBC ACF 152 suppresses noise of the DC voltage.

[0065] The PFC 154 steps up the DC voltage (lower voltage) supplied from the OBC ACF 152. In addition, the PFC 154 is configured by any one of a bridge type PFC circuit, a bridgeless PFC circuit, and a totem pole type PFC circuit, and the like. Therefore, the PFC 154 can step up the DC voltage.

[0066] In particular, in the present embodiment, the charging circuit 180 can supply the household AC 100 V to the in-vehicle power supply connector 110. Therefore, the PFC 154 in the charging circuit 180 is configured by a PFC circuit in which all switching elements are used instead of diodes. The PFC circuit in which all switching elements are used is, for example, a bridgeless PFC circuit or a totem pole type PFC circuit.

[0067] The insulation type DCDC converter 170 steps up the DC voltage supplied from the PFC 154, and becomes a voltage that enables the auxiliary machine DDC 200 to operate stably. Thus, in the present embodiment, the charging circuit 180 that converts from the AC voltage to the DC voltage during the AC charging functions as a voltage conversion circuit (voltage step-up circuit) when the voltage of the battery 106 before charging is lower than the predetermined value described above. In the present embodiment, both the PFC 154 and the insulation type DCDC converter 170 in the charging circuit 180 function as the voltage conversion circuit (voltage step-up circuit). However, as a modification, either the PFC 154 or the insulation type DCDC converter 170 can function as the voltage conversion circuit (voltage step-up circuit).

[0068] The DCF 190 suppresses noise of the stepped-up DC voltage supplied from the insulation type DCDC converter 170. The voltage from the DCF 190 (voltage generated by the DCF 190) is applied to the auxiliary machine DDC 200.

[0069] Further, the DC voltage from the first connector 111 is supplied to the battery 106 via the second switch device 302 and the third switch device 303. Thereby, the power from the DCF 190 is supplied to the auxiliary machine DDC 200. In addition, since the first switch device 301 is open, the pair of first power lines 350 is cut off between the output of the charging circuit 180 (secondary circuit 160) and the input of the auxiliary machine DDC 200 (primary circuit 202). Thus, it is possible to suppress a case where the current from the DCF 190 flows to the battery 106 or a case where the current from the battery 106 flows to the DCF 190.

[0070] Further, the auxiliary machine DDC 200 supplies the stable power from the DCF 190 to the auxiliary machine group (auxiliary machines, auxiliary battery). The auxiliary battery is charged by the supplied power.

[0071] [Flowchart]

[0072] Figure 3 is a flowchart of the process performed by the ECU 320 of the present embodiment. First, in step S2, the ECU 320 determines which one of the AC voltage and the DC voltage is the supply voltage supplied from the charger 113, based on the voltage type signal from the charger 113. In a case where the supply voltage is the AC voltage (YES in step S2), the process proceeds to step S4.

[0073] In step S4, the ECU 320 closes the first switching device 301, opens the second switching device 302, and closes the third switching device 303. Also, the ECU 320 operates the charging circuit 180. The ECU 320 is able to perform power factor improvement and conversion of the AC voltage to the DC voltage by the charging circuit 180 and supply electric power to the battery 106 and the auxiliary machine DDC 200 by executing the process of this step S4.

[0074] On the other hand, in step S2, in the case where the supply voltage is the DC voltage (NO in step S2), in step S6, the ECU 320 determines whether the voltage of the battery 106 is the predetermined value or more. In the case where the voltage of the battery 106 is the predetermined value or more (YES in step S6), in step S8, the ECU 320 requests a higher start voltage to the charger 113. Next, in step S10, the ECU 320 closes all of the first switching device 301, the second switching device 302, and the third switching device 303. Also, the ECU 320 does not operate the charging circuit 180 for charging. The ECU 320 is able to supply electric power to the battery 106 and the auxiliary machine DDC 200 by executing the process of this step S10.

[0075] On the other hand, in step S6, in the case where the voltage of the battery 106 is less than the predetermined value (NO in step S6), in step S12, the ECU 320 requests a lower start voltage to the charger 113. Next, in step S14, the ECU 320 opens the first switching device 301 and closes the second switching device 302 and the third switching device 303. Also, the ECU 320 operates the charging circuit 180. The ECU 320 is able to charge the battery 106 and supply stable electric power to the auxiliary machine DDC 200, that is, the auxiliary machine group 108, even for a lower start voltage, by executing the process of this step S14.

[0076] In addition, the condition that the voltage of the battery 106 is less than the predetermined value in step S6 (NO in step S6) corresponds to one example of the "predetermined condition related to charging of the battery" of the present disclosure. In other words, when this predetermined condition is established (when NO is determined in step S6), the ECU 320 executes the process of step S14.

[0077] [SUMMARY]

[0078] (1) In the above, in the present embodiment, the charging system 100 executes the above-described voltage control (steps S8, S12) for the protection of the battery 106. Therefore, it is possible to suppress the damage of the battery 106. In a case where the voltage of the battery 106 before charging is higher than the predetermined value (YES in step S6), the first switching device 301, the second switching device 302, and the third switching device 303 are all closed (step S10). Thereby, it is possible to apply sufficient voltage to the battery 106 and the auxiliary machine DDC 200.

[0079] On the other hand, in a case where the voltage of the battery 106 before charging is lower than the predetermined value, it is not possible to apply sufficient voltage to the charging device 300 by executing the above-described voltage control. In a case where it is not possible to apply sufficient voltage to the charging device 300, it is not possible to apply sufficient voltage to the auxiliary machine DDC 200. In a case where it is not possible to apply sufficient voltage to the auxiliary machine DDC 200, a problem can occur that it is not possible to supply power to the ECU 320 and the switching devices (the first switching device 301 to the third switching device 303) and the like during the charging of the battery 106, and it is not possible to charge the battery 106. In addition, a problem can occur that it is not possible to supply power to the in-vehicle air conditioner and the temperature adjustment device of the battery 106.

[0080] Therefore, the charging system 100 of the present embodiment opens the first switching device 301, and closes the second switching device 302 and the third switching device 303 (step S14). Also, the charging system 100 operates both the PFC 154 and the insulation type DCDC converter 170. Thereby, the PFC 154 and the insulation type DCDC converter 170 can step up the lower voltage from the charger 113 and apply it to the DCF 300. Also, the voltage generated by the DCF 300 (the voltage after being stepped up by the PFC 154 and the insulation type DCDC converter 170) is applied to the auxiliary machine DDC 200.

[0081] Therefore, the charging system 100 can supply stable power to the auxiliary machine group 108 regardless of the voltage of the battery 106 during the charging of the battery 106. In particular, the charging system 100 can supply power to the charging of the battery 106 and the auxiliary machine DDC 200 even in a case where the voltage of the battery 106 is lower than the predetermined value. Therefore, the charging system 100 suppresses the occurrence of the above-described problems.

[0082] In particular, in the present embodiment, the charging circuit 180 (particularly, the PFC 154 and the insulation-type DCDC converter 170) used in AC charging is used as a step-up circuit in DC charging. Therefore, it is possible to step up the DC voltage from the charger 113 without adding a special circuit to the charging device 300. In other words, the charging system 100 of the present embodiment can use the charging circuit 180 for AC as a circuit for DC. Therefore, the charging system 100 of the present embodiment does not need to separately have the charging circuit 180 used in AC charging and the step-up circuit for DC charging. Therefore, compared with the existing charging system, the charging system 100 of the present embodiment can reduce the number of components.

[0083] (2) Further, in a case where the supply voltage is an AC voltage, the charging system 100 performs the process of step S4. Thereby, it is possible to supply electric power to the auxiliary machine DDC 200 and the battery 106.

[0084] <2nd Embodiment>

[0085] Figure 4 is a configuration example of the charging system 100A of the 2nd embodiment. The battery 106 of the charging system 100A includes a 1st module 106A and a 2nd module 106B. The 1st module 106A includes at least one battery cell. The 2nd module 106B includes at least one battery cell. The 1st module 106A and the 2nd module 106B are, for example, 400 V voltage. Also, the charging system 100A has a 1st switching circuit 400 including a 1st relay 401, a 2nd relay 402, and a 3rd relay 403.

[0086] One end of the 1st relay 401 is connected to the negative side of the 1st module 106A, and the other end of the 1st relay 401 is connected to the low-voltage power line 350L (the negative side of the 2nd module 106B). One end of the 2nd relay 402 is connected to the negative side of the 1st module 106A, and the other end of the 2nd relay 402 is connected to the positive side of the 2nd module 106B. One end of the 3rd relay 403 is connected to the positive side of the 2nd module 106B, and the other end of the 3rd relay 403 is connected to the high-voltage power line 350H (the positive side of the 1st module 106A).

[0087] The 1st switching circuit 400 is a circuit that switches the state of the charging system 100A between a 1st state and a 2nd state. The 1st state is a state in which the 1st module 106A and the 2nd module 106B are connected in series between a pair of 1st power lines 350. The 2nd state is a state in which the 1st module 106A and the 2nd module 106B are connected in parallel with respect to the pair of 1st power lines 350.

[0088] In Figure 4In the example of FIG. 4, the first state is a state in which the first relay 401 and the third relay 403 are open, and the second relay 402 is closed. The second state is a state in which the first relay 401 and the third relay 403 are closed, and the second relay 402 is open. The sensor 107 detects the line-to-line voltage of the pair of first power lines 350 as the voltage of the battery 106 in both the first state and the second state.

[0089] For example, in a case where the vehicle 1000 is driven (in a case where the electrical load 104 is operated), the ECU 320 closes the third switching device 303. Thereby, the electrical power from the battery 106 is supplied to the electrical load 104. Also, in a case where the third switching device 303 is closed, the ECU 320 causes the first switching circuit 400 to be in the first state (a state in which the first module 106A and the second module 106B are connected in series). Thereby, the charging system 100A can supply a larger voltage to the electrical load 104 by connecting the first module 106A and the second module 106B in series.

[0090] Further, in a case where the DC voltage supplied from the external charger 113 to the first connector 111 is higher than a predetermined voltage, the ECU 320 causes the first switching circuit 400 to be in the first state. Here, the predetermined voltage is, for example, 600 V. Further, the case where the DC voltage supplied to the first connector 111 is higher than the predetermined voltage is, for example, a case where the rated voltage of the DC voltage supplied from the charger 113 is 800 V. In other words, this case is a case where the battery 106 is charged by the charger 113 for a battery of 800 V.

[0091] On the other hand, there is a case where the DC voltage supplied from the external charger 113 to the first connector 111 is lower than the predetermined voltage. This case is, for example, a case where the rated voltage of the DC voltage supplied from the charger 113 is 400 V. In other words, this case is a case where the battery 106 is charged by the charger 113 for a battery of 400 V.

[0092] In a case where the ECU 320 charges by the charger 113 for a battery of 400 V, the ECU 320 causes the first switching circuit 400 to be in the second state (a state in which the first module 106A and the second module 106B are connected in parallel). Thereby, the charging system 100A can charge both the first module 106A and the second module 106B at a lower voltage compared to the case where the first module 106A and the second module 106B are connected in series.

[0093] In addition, the ECU 320 can determine which one of 400 V and 800 V is the DC voltage supplied from the charger 113 by communicating with the charger 113.

[0094] Further, for example, the 1st module 106A and the 2nd module 106B are each configured of 100 battery cells each of which is used under a condition of 2.5 V to 4.2 V. In this case, if the battery 106 is during discharging, since the 1st module 106A and the 2nd module 106B are connected in series, the auxiliary DDC 200 needs to be designed to withstand application of a voltage of 500 V to 840 V.

[0095] Further, if the battery 106 is during charging, since the 1st module 106A and the 2nd module 106B are connected in parallel, the auxiliary DDC 200 needs to be designed to withstand application of a voltage of 250 V to 420 V. In other words, in the auxiliary DDC 200, in fact, it is necessary to be designed to withstand application of a voltage in a larger voltage range such as 250 V to 840 V. In the existing auxiliary DDC, it is designed to withstand such a larger voltage range, and in the case where the DC charging is 400 V and the voltage of the battery 106 is low, it is not easy to design the auxiliary DDC 200.

[0096] In this regard, in the present embodiment, as will be described below, for example, it is possible to make the auxiliary DDC 200 a voltage withstand design that withstands a voltage in a voltage range of 500 V to 840 V. This voltage range (500 V to 840 V) is a voltage range that can be applied to the auxiliary DDC 200 when the 1st module 106A and the 2nd module 106B are in a state of being connected in series (1st state).

[0097] By being thus configured, it is possible to make the design of the auxiliary DDC 200 relatively easy. In addition, even in the case where, since the DC charging is 400 V and the voltage of the battery 106 becomes the 2nd state and is lower than the predetermined value, the charging system 100A boosts the 400 V of the DC charging by the charging circuit 180 in such a manner that it becomes within the range of 500 V to 840 V and supplies the voltage after the boosting to the auxiliary DDC 200. Thereby, the voltage supplied to the auxiliary DDC 200 belongs to the voltage range (500 V to 840 V) involved in the above voltage withstand design of the auxiliary DDC 200, and it is possible to supply sufficient electric power to the auxiliary DDC 200, and it is possible to supply stable electric power to the auxiliary group 108. Therefore, it is possible to narrow the voltage range involved in the above voltage withstand design of the auxiliary DDC 200.

[0098] Further, in the above 1st embodiment, it is described that the predetermined condition related to charging of the battery includes the condition that the voltage of the battery 106 is lower than the predetermined value. However, in this 2nd embodiment, the predetermined condition can also be other conditions. Hereinafter, the other conditions will be described.

[0099] It is understood that the voltage of the battery 106 changes significantly depending on which of the first state and the second state the state of the first switching circuit 400 is. Therefore, it can also be that the ECU 320 determines that the voltage of the battery 106 is higher than the predetermined value when the state of the first switching circuit 400 is the first state. It can also be that the ECU 320 determines that the voltage of the battery 106 is lower than the predetermined value when the state of the first switching circuit 400 is the second state.

[0100] Further, it can also be that the predetermined condition includes a condition that the direct current voltage supplied to the first connector 111 is lower than a predetermined voltage (600 V) (in other words, a condition that DC charging of 400 V is performed). Figure 5 is a flowchart of the process performed by the ECU 320 of the second embodiment in the case where such a structure is employed.

[0101] Figure 5 In this case, Figure 3 Step S6 of is replaced by Step S6A, and Steps S8 and S12 are not executed. In Step S6A, the ECU 320 determines whether the direct current voltage supplied to the first connector 111 is the predetermined voltage or more. In the case where the determination in Step S6A is "Yes", the ECU 320 does not execute the process of Step S8, but executes the process of Step S10. Further, in the case where the determination in Step S6A is "No", the ECU 320 does not execute the process of Step S12, but executes the process of Step S14.

[0102] Further, it can also be that, in Step S6A, the ECU 320 determines whether the state of the first switching circuit 400 is the first state, as indicated by the parentheses of Step S6A. In the case where the determination in Step S6A is "Yes", the ECU 320 does not execute the process of Step S8, but executes the process of Step S10. Further, in the case where the determination in Step S6A is "No", the ECU 320 does not execute the process of Step S12, but executes the process of Step S14. In the structure of the parentheses of Step S6A, a condition that the state of the first switching circuit 400 is the second state is included.

[0103] <3rd Embodiment>

[0104] Figure 4In the case where the difference between the voltage of the first module 106A and the voltage of the second module 106B becomes large as discharging progresses, the first module 106A and the second module 106B do not appropriately perform charging and discharging based on the first module 106A and the second module 106B, and the battery capacity cannot be sufficiently utilized. In addition, the number of battery cells in the first module 106A and the second module 106B can be different. In the third embodiment, even in the case where the difference between the voltage of the first module 106A and the voltage of the second module 106B is large, the adjustment circuit corresponding to the difference is applied.

[0105] Figure 6 is a configuration example of a charging system 100B of the third embodiment. The charging system 100B is a system obtained by adding an adjustment circuit 500 to the charging system 100A. Figure 4

[0106] The adjustment circuit 500 steps up or steps down the voltage of the pair of first power lines 350. In the second state, the adjustment circuit 500 applies the stepped-up or stepped-down voltage to the second module 106B. In the third state, the adjustment circuit 500 applies the stepped-up or stepped-down voltage to the first module 106A. Figure 6 In the adjustment circuit 500, the adjustment circuit 500 is a step-up / down converter that steps up or steps down the voltage of the pair of first power lines 350.

[0107] According to such a configuration, for example, at the time of DC charging, a voltage higher than the voltage applied to the first module 106A or a voltage lower than the voltage applied to the first module 106A can be applied to the second module 106B. In addition, the charging system 100B can output only the voltage corresponding to the first module 106A from the charger 113. Therefore, even in the case where the difference between the voltage of the first module 106A and the voltage of the second module 106B is large, the charging system 100B can cope with the difference. That is, the adjustment circuit 500 can eliminate the imbalance of the voltage, or can charge even in the case where the number of battery cells is different.

[0108] In addition, the adjustment circuit 500 is not limited to the step-up / down converter, and can be an inverter or a motor, or the like.

[0109] <Fourth Embodiment>

[0110] Figure 7 is a configuration example of a charging system 100C of the fourth embodiment. The charging system 100C has a second connector 112 in addition to the first connector 111. The first connector 111 of the charging system 100C is applied with a DC voltage. The second connector 112 of the charging system 100C is applied with an AC voltage.

[0111] ​Further, the charging system 100C has a second switching circuit 304 for switching the voltage input to the charging device 300 (the charging circuit 180), that is, switching between the first connector 111 and the second connector 112. The second switching circuit 304 includes a high-voltage side relay 304H and a low-voltage side relay 304L.

[0112] For the ECU 320, on the one hand, in a case where the DC voltage is applied and the voltage of the battery 106 is lower than a predetermined value, the second switching circuit 304 is switched to a first state in which the first connector 111 and the charging device 300 are made conductive. On the other hand, in a case where the AC voltage is applied, the second switching circuit 304 is switched to a second state in which the second connector 112 and the charging device 300 are made conductive. According to such a structure, the connector to which the DC voltage is applied and the connector to which the AC voltage is applied can be clearly distinguished. In this way, the idea of the present disclosure can also be applied to a vehicle in which the connector to which the DC voltage is applied and the connector to which the AC voltage is applied are provided separately.

[0113] <5th Embodiment>

[0114] Figure 8 is a configuration example of a charging system 100D of the 5th embodiment. In the charging system 100D, a pair of power lines 360 is further provided. The pair of power lines 360 corresponds to the "pair of second power lines" of the present disclosure. The pair of power lines 360 each connects the pair of first power lines 350 each to the electrical load 104. Specifically, the pair of power lines 360 has a high-voltage power line 360H and a low-voltage power line 360L. Further, the high-voltage power line 350H is connected to the high-voltage power line 360H, and the low-voltage power line 350L is connected to the low-voltage power line 360L. Moreover, the third switching device 303 is disposed to the pair of power lines 360.

[0115] Further, in a case where the electrical load 104 is operated (for example, in a case where the vehicle 1000 is driven), the ECU 320 closes the third switching device 303. On the other hand, in a case where the battery 106 is charged, the ECU 320 opens the third switching device 303.

[0116] According to the charging system 100D, in a case where the electrical load 104 is operated, the voltage can be appropriately applied to the electrical load 104. On the other hand, in a case where the battery 106 is charged, the battery 106 can be insulated from the electrical load 104.

[0117] <6th Embodiment>

[0118] In the above-described embodiments, an example in which the same auxiliary machine DDC 200 is used in both cases of discharging and charging the battery 106 has been described. However, a structure in which different auxiliary machine DDCs are used in discharging and charging the battery 106 can also be adopted.

[0119] Figure 9 is a configuration example of a charging system 100E of the 6th embodiment. In the charging system 100E, a structure capable of supplying a voltage to the auxiliary machine DDC 700 from the middle of the charging circuit 180 is adopted. In other words, the auxiliary machine DDC 700 can be supplied with power from the so-called DC link voltage on the side of the insulation type DCDC converter 170 of the PFC 154. The auxiliary machine DDC 700 adopts the same structure as the auxiliary machine DDC 200, for example.

[0120] In Figure 9 the example, when the battery 106 is charged in a case where the voltage of the battery 106 supplied at the 1st connector 111 is lower than a predetermined value, the auxiliary machine DDC 700 can supply stable power to the auxiliary machine group 108. On the other hand, when the battery 106 is discharged, the auxiliary machine DDC 200 supplies power to the auxiliary machine group 108.

[0121] Figure 10 is a configuration example of another charging system 100F of the 6th embodiment. Figure 10 In the example of , a winding of a secondary circuit 161 different from the charging circuit 180 is magnetically coupled to the core of the transformer 158 and capable of supplying a voltage to the secondary circuit 161. Moreover, the auxiliary machine DDC 700 can be supplied with a voltage from the secondary circuit 161.

[0122] The charging system adopting such a structure can also have the same effects as the above-described embodiments.

[0123] <7th Embodiment>

[0124] In the 7th embodiment, another example of Figure 7 will be described. Figure 11 is a configuration example of a charging system 100G of the 1st example of the 7th embodiment. The 2nd state of the 2nd switching circuit 304 in the charging system 100G is a state in which the 2nd connector 112 is connected to the OBC ACF 152 (the state of Figure 11 ). In addition, the 1st state of the 2nd switching circuit 304 is a state in which the pair of 1st power lines 350 (the branched power line 351) on the side of the battery 106 is connected to the OBC ACF 152 (the charging circuit 180) through the power line 362.

[0125] Further, in a case where the AC is charged, the ECU 320 switches the 2nd switching circuit 304 to the 2nd state. Thereby, the charging circuit 180 is able to convert the AC voltage to the DC voltage and supply to the auxiliary machine DDC 200 and the battery 106.

[0126] Further, in a case where the DC voltage is supplied at the 1st connector 111, the battery 106 is charged when the voltage of the battery 106 is lower than the predetermined value, the ECU 320 switches the 2nd switching circuit 304 to the 1st state. At the same time, the ECU 320 opens the 1st switching device 301. Thereby, the DC voltage from the 1st connector 111 is boosted by the charging circuit 180 via the power line 362. Therefore, the charging system 100G boosts the voltage from the battery 106 and supplies to the auxiliary machine DDC 200, and is able to supply the stable electric power to the auxiliary machine group 108.

[0127] Figure 12 is a configuration example of the charging system 100H which is the 2nd example of the 7th embodiment. The 2nd state of the 2nd switching circuit 304 is a state of connecting the in-vehicle power supply connector 110 with the OBC ACF 152 (the state of Figure 12 Further, the 1st state of the 2nd switching circuit 304 is a state of connecting the battery 106 with the OBC ACF 152 (the charging circuit 180).

[0128] Further, in a case where the AC is charged, the ECU 320 switches the 2nd switching circuit 304 to the 2nd state. Thereby, the charging circuit 180 is able to convert the AC voltage to the DC voltage and supply to the auxiliary machine DDC 200 and the battery 106.

[0129] Further, in a case where the DC voltage is supplied at the 1st connector 111, the battery 106 is charged when the voltage of the battery 106 is lower than the predetermined value, the ECU 320 switches the 2nd switching circuit 304 to the 1st state. At the same time, the ECU 320 opens the 1st switching device 301. Thereby, the DC voltage from the 1st connector 111 is boosted by the charging circuit 180 via the power line 362. Therefore, the charging system 100G boosts the voltage from the battery 106 and supplies to the auxiliary machine DDC 200, and is able to supply the stable electric power to the auxiliary machine group 108.

[0130] Figure 13 is a configuration example of the charging system 100H which is the 2nd example of the 7th embodiment. The 2nd state of the 2nd switching circuit 304 is a state of connecting the in-vehicle power supply connector 110 with the OBC ACF 152 (the state of Figure 13 Further, the 1st state of the 2nd switching circuit 304 is a state of connecting the battery 106 with the OBC ACF 152 (the charging circuit 180).

[0131] Further, in a case where the electrical load 104 is operating (for example, in a case where the vehicle 1000 is being driven), the ECU 320 switches the second switching circuit 304 to the second state. Also, the ECU 320 causes the first switching device 301 to be closed. Thereby, a DC voltage is supplied from the battery 106 via the DCF 190 to the in-vehicle power supply connector 110 and the auxiliary machine DDC 200.

[0132] Further, in a case where the voltage of the battery 106 is lower than a predetermined value when the battery 106 is being charged with the DC voltage supplied at the first connector 111, the ECU 320 switches the second switching circuit 304 to the first state. Thereby, the charging circuit 180 steps up the DC voltage and supplies it to the auxiliary machine DDC 200, and supplies stable electric power to the auxiliary machine group 108.

[0133] The charging system having such a configuration also has the same effects as the above-described embodiments.

[0134] [Supplementary note]

[0135] (1) The charging system for a vehicle according to the present disclosure is mounted on a vehicle. The charging system includes a battery that stores electric power used to generate drive power of the vehicle; a first connector that is supplied with at least a DC voltage from an external charger; a pair of first power lines that link the battery and the first connector. Further, the charging system includes a charging circuit that charges the battery by converting an AC voltage supplied from the external charger into a DC voltage and outputting it to the pair of power lines; an auxiliary machine DCDC converter that converts a voltage of the battery input from the pair of power lines and supplies the converted voltage to an auxiliary machine group including at least an auxiliary machine; a first switching device that is disposed between the pair of first power lines and an output side of the charging circuit and an input side of the auxiliary machine DCDC converter; and a control circuit. The charging circuit includes a power factor improvement circuit and a charging DCDC converter that steps up a DC voltage output from the power factor improvement circuit. When a predetermined condition related to charging of the battery is satisfied, the control circuit opens the first switching device, thereby cutting off the pair of power lines from the output side of the charging circuit and the input side of the auxiliary machine DCDC converter, and supplies the DC voltage supplied to the first connector to the charging circuit and causes at least one of the power factor improvement circuit and the charging DCDC converter to operate, thereby supplying the DC voltage stepped up by the charging circuit to the auxiliary machine group.

[0136] According to such a structure, the charging circuit is able to charge the battery by converting the AC voltage into a DC voltage and outputting the DC voltage to the pair of power lines in a case where the AC voltage is input from the external charger. Also, the charging circuit is able to supply the auxiliary machine group with the DC voltage obtained by transforming the DC voltage using the charging circuit by operating at least one of the power factor improvement circuit and the charging DC-DC converter in a case where the DC voltage is input from the external charger. Therefore, the auxiliary machine group is able to be supplied with stable electric power regardless of the voltage of the battery.

[0137] (2) In the charging system for a vehicle according to (1), the predetermined condition includes a condition that the voltage supplied to the first connector is a DC voltage and the voltage of the battery is lower than a predetermined value.

[0138] According to such a structure, the DC voltage transformed using the charging circuit is able to be supplied to the auxiliary machine group even in a case where the voltage of the battery is lower than the predetermined value.

[0139] (3) In the charging system for a vehicle according to (2), in a case where the voltage supplied to the first connector is a DC voltage and the voltage of the battery is higher than a predetermined value, the control circuit closes the first switching device, and thereby, the DC voltage from the pair of first power lines is supplied to the auxiliary machine group.

[0140] According to such a structure, in a case where the voltage of the battery is higher than the predetermined value, the charging circuit is not required to be used for charging, and thereby, a loss caused by the operation of the charging circuit is able to be reduced, or the charging circuit is able to be used in a case where the in-vehicle power supply connector is supplied with electric power by operating the charging circuit in reverse.

[0141] (4) In the charging system for a vehicle according to (3), in a case where the voltage supplied to the first connector is a DC voltage, the control circuit transmits a request signal to the charger, the request signal being a signal for requesting the charger to request a start-time voltage at which charging of the battery is started by the DC voltage. Also, for the control circuit, the start-time voltage requested by the request signal in a case where the voltage of the battery is lower than the predetermined value is lower than the start-time voltage requested by the request signal in a case where the voltage of the battery is higher than the predetermined value.

[0142] According to such a structure, damage to the battery is suppressed, and the DC voltage transformed by the charging circuit is able to be supplied to the auxiliary machine group regardless of the voltage of the battery.

[0143] (5) In the charging system for a vehicle described in (1), the battery includes a first module including at least one battery cell, and a second module including at least one battery cell. The charging system for a vehicle further includes a switching circuit that switches between a first state in which the first module and the second module are connected in series between a pair of first power lines, and a second state in which the first module and the second module are connected in parallel with respect to the pair of first power lines. The predetermined condition includes a condition in which a direct current voltage supplied to the first connector is lower than a predetermined voltage, or a condition in which the state of the switching circuit is the second state.

[0144] According to such a configuration, it is possible to reduce the voltage range of the withstand voltage of the auxiliary machine DCDC converter.

[0145] Further, it can also be that, in a case where the direct current voltage supplied to the first connector is higher than the predetermined voltage, the control circuit causes the state of the switching circuit to be the first state. Further, it can also be that, in a case where the direct current voltage supplied to the first connector is lower than the predetermined voltage, the control circuit causes the state of the switching circuit to be the second state.

[0146] (6) In the charging system for a vehicle described in (5), the charging system for a vehicle further includes an adjustment circuit that steps down the voltage of the pair of first power lines, and applies the stepped-down voltage to the second module.

[0147] According to such a configuration, even in a case where the difference between the voltage of the first module and the voltage of the second module is large, it is possible to charge the battery in response to the difference.

[0148] (7) In the charging system for a vehicle described in (1) to (6), the charging system for a vehicle further includes a second switching device disposed on the pair of first power lines. In a case where the voltage supplied to the first connector is an alternating current voltage, the control circuit closes the first switching device and opens the second switching device, and causes the charging circuit to operate. Further, in a case where the voltage supplied to the first connector is a direct current voltage, the control circuit closes the second switching device.

[0149] According to such a configuration, even in a case where the voltage supplied from the first connector is an alternating current voltage, it is possible to apply the voltage to the battery and the auxiliary machine DCDC converter.

[0150] (8) In the charging system for a vehicle described in (1) to (7), the first connector is supplied with a direct current voltage. Further, the charging system for a vehicle further includes a second connector that is supplied with an alternating current voltage.

[0151] According to such a configuration, it is possible to clearly distinguish between the connector to which a direct current voltage is applied and the connector to which an alternating current voltage is applied.

[0152] (9) In the charging system for a vehicle according to any one of (1) to (8), the charging system further includes an electric load that generates a driving force of the vehicle by the electric power of the battery, a pair of second electric power lines that connect between the electric load and each of the pair of first electric power lines, and a third switching device that is provided to the pair of second electric power lines. In a case where the electric load is operated, the control circuit closes the third switching device. In a case where the battery is charged, the control circuit opens the third switching device.

[0153] According to such a configuration, in a case where the battery is discharged, the third switching device is closed, and thus, the electric load can be supplied with the electric power from the battery. Further, in a case where the battery is charged, the third switching device is opened, and thus, it is possible to suppress a situation where unnecessary electric power is supplied to the electric load.

[0154] In addition, in the circuit configuration of each embodiment, there is a concern that a DC voltage is applied to the terminals of the second connector 112 and the in-vehicle power supply connector 110, and thus, a switching device, a switching circuit, or the like that has a function of cutting off can be provided to a wiring that is connected to the circuit of the OBC ACF 152 and the PFC 154 or the second connector 112 and the in-vehicle power supply connector 110.

[0155] Embodiments of the present application have been described, but it should be considered that the embodiments disclosed this time are all illustrative in all respects and are not limitative. The scope of the present application is shown by the claims, and is intended to include all modifications within the meaning and range equivalent to the claims.

Claims

1. A vehicle charging system, which is a vehicle charging system mounted on a vehicle, characterized in that: have: a battery that stores electricity for generating driving force for the vehicle; a first connector to which at least a DC voltage is supplied from an external charger; a pair of first power lines connecting the battery to the first connector; a charging circuit that charges the battery by converting an AC voltage supplied from an external charger into a DC voltage and outputting the DC voltage to the pair of first power lines; an auxiliary machine DCDC converter that converts a voltage of the battery input from the pair of first power lines and supplies the converted voltage to an auxiliary machine group including at least an auxiliary machine; a first switching device disposed between the pair of first power lines and the output terminal side of the charging circuit and the input terminal of the auxiliary machine DCDC converter; as well as control circuit, The charging circuit has: Power factor improvement circuit; as well as a charging DCDC converter that transforms the DC voltage output from the power factor improvement circuit, When a predetermined condition related to charging of the battery is satisfied, the control circuit opens the first switching device to disconnect the pair of first power lines from the output end of the charging circuit and the input end of the auxiliary machine DC-DC converter. Furthermore, the control circuit supplies the DC voltage supplied to the first connector to the charging circuit and activates at least one of the power factor improvement circuit and the charging DC-DC converter. As a result, the DC voltage transformed by the charging circuit is supplied to the auxiliary machine group.

2. The vehicle charging system according to claim 1, wherein: The predetermined condition includes a condition that the voltage supplied to the first connector is a DC voltage and the voltage of the battery is lower than a predetermined value.

3. The vehicle charging system according to claim 2, wherein: When the voltage supplied to the first connector is a DC voltage and the battery voltage is higher than the predetermined value, the control circuit closes the first switching device to supply the DC voltage from the pair of first power lines to the auxiliary machine group.

4. The vehicle charging system according to claim 3, wherein: When the voltage supplied to the first connector is a DC voltage, the control circuit transmits a request signal to the charger, the request signal being a signal for requesting the charger to set a starting voltage when starting charging of the battery using the DC voltage. The start voltage requested by the request signal when the battery voltage is lower than a predetermined value is lower than the start voltage requested by the request signal when the battery voltage is higher than the predetermined value.

5. The vehicle charging system according to claim 1, wherein: The battery comprises: a first module comprising at least one battery cell; and A second module comprising at least one battery cell, The vehicle charging system further includes a switching circuit for switching between a first state in which the first module and the second module are connected in series between the pair of first power lines and a second state in which the first module and the second module are connected in parallel with respect to the pair of first power lines. The predetermined condition includes a condition that the DC voltage supplied to the first connector is lower than a predetermined voltage, or a condition that the state of the switching circuit is the second state.

6. The vehicle charging system according to claim 5, wherein: The vehicle charging system further includes a regulator circuit that transforms the voltage of the pair of first power lines and applies the transformed voltage to the second module.

7. The vehicle charging system according to any one of claims 1 to 6, wherein: The vehicle charging system further includes a second switch device disposed on the pair of first power lines. For the control circuit, When the voltage supplied to the first connector is an AC voltage, the control circuit closes the first switching device and opens the second switching device to operate the charging circuit. When the voltage supplied to the first connector is a DC voltage, the control circuit closes the second switching device.

8. The vehicle charging system according to any one of claims 1 to 6, wherein: The first connector is supplied with a DC voltage, A second connector to which an AC voltage is supplied is further provided.

9. The vehicle charging system according to any one of claims 1 to 6, wherein: The charging system further comprises: an electrical load that generates driving force for the vehicle using electricity from the battery; a pair of second power lines connecting each of the pair of first power lines to the electrical load; as well as a third switch device disposed on the pair of second power lines, For the control circuit, When the electrical load is operated, the control circuit closes the third switching device; when the battery is charged, the control circuit opens the third switching device.

10. A charging circuit mounted on a vehicle and configured to charge a battery, wherein the vehicle includes a battery storing electric power for generating a driving force for the vehicle, wherein the charging circuit is characterized in that: The vehicle has: a first connector to which at least a DC voltage is supplied from an external charger; a pair of first power lines connecting the battery to the first connector; an auxiliary machine DCDC converter that converts a voltage of the battery input from the pair of first power lines and supplies the converted voltage to an auxiliary machine group including at least an auxiliary machine; as well as a first switching device disposed between the pair of first power lines, the output terminal side of the charging circuit, and the input terminal of the auxiliary machine DCDC converter; The charging circuit has: Power factor improvement circuit; as well as a charging DCDC converter that transforms the DC voltage output from the power factor improvement circuit, For the charging circuit, The battery is charged by converting an AC voltage supplied from an external charger into a DC voltage and outputting the DC voltage to the pair of first power lines. When a predetermined condition related to charging the battery is satisfied, the charging circuit opens the first switching device to disconnect the pair of first power lines from the output end of the charging circuit and the input end of the auxiliary machine DC-DC converter. Furthermore, the DC voltage supplied to the first connector is supplied to the charging circuit, and at least one of the power factor improvement circuit and the charging DC-DC converter is operated. As a result, the DC voltage transformed by the charging circuit is supplied to the auxiliary machine group.

11. A charging device, characterized in that: have: The charging circuit according to claim 10 and the auxiliary machine DCDC converter.

12. A voltage control method in a vehicle, characterized in that: The vehicle has: a battery that stores electricity for generating driving force for the vehicle; a first connector to which at least a DC voltage is supplied from an external charger; a pair of first power lines connecting the battery to the first connector; a charging circuit that charges the battery by converting an AC voltage supplied from an external charger into a DC voltage and outputting the DC voltage to the pair of first power lines; an auxiliary machine DCDC converter that converts a voltage of the battery input from the pair of first power lines and supplies the converted voltage to an auxiliary machine group including at least an auxiliary machine; as well as a first switching device disposed between the pair of first power lines, the output terminal side of the charging circuit, and the input terminal of the auxiliary machine DCDC converter; The charging circuit has: Power factor improvement circuit; and a charging DCDC converter that transforms the DC voltage output from the power factor improvement circuit, The control method includes the steps of: when a predetermined condition related to charging the battery is satisfied, opening the first switching device to disconnect the pair of first power lines from the output end of the charging circuit and the input end of the auxiliary machine DC-DC converter, supplying the DC voltage supplied to the first connector to the charging circuit and operating at least one of the power factor improvement circuit and the charging DC-DC converter, thereby supplying the DC voltage transformed by the charging circuit to the auxiliary machine group.

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