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

Abstract

To supply stable electric power to an auxiliary machine group regardless of a battery voltage during charging of the battery.SOLUTION: An ECU 320, when a voltage supplied to a first connector 111 is a DC voltage and a voltage of a battery 106 is higher than a predetermined value, closes a first switchgear 301 to apply the DC voltage from a pair of first power lines 350 to an auxiliary machine DDC 200. When the voltage supplied to the first connector 111 is a DC voltage and the voltage of the battery 106 is lower than the predetermined value, the ECU 320 opens the first switchgear 301 and operates at least one of a PFC 154 and an isolated DCDC converter 170 to apply, to an auxiliary machine group 108, a DC voltage converted by a charging circuit 180.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] JP 2021-141545 A (Patent Document 1) discloses a power supply system for an electric vehicle. In this power supply system, a DC voltage is supplied to the electric vehicle from an external charger installed at a charging station to charge the battery. Specifically, this power supply system has a DC power inlet, and charges the battery with a DC voltage supplied from the external charger that corresponds to the battery's state. If the battery is not charged enough and the battery voltage is lower than normal, the supplied DC voltage will also be lower. This charging is also called rapid charging.

[0003] Furthermore, Japanese Patent Application Laid-Open No. 2023-047162 (Patent Document 2) discloses a technique for switching the connection of cells constituting a battery between series and parallel connections depending on the charging and discharging of the battery. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-141545 [Patent Document 2] Japanese Patent Publication No. 2023-047162 Summary of the Invention [Problem to be solved by the invention]

[0005] Typically, an electric vehicle has an auxiliary DC-DC converter that steps down a battery voltage of, for example, 400V to 14V and supplies the voltage to the vehicle's auxiliary devices. The auxiliary devices include an ECU (Electronic Control Unit) for controlling the vehicle, a charging relay, an air conditioner, a battery temperature regulator, and audio equipment. It is desirable for these devices included in the auxiliary devices to operate even while the battery is being charged. In other words, in an electric vehicle, it is desirable to supply a stable power supply to the auxiliary devices even while the battery is being charged.

[0006] However, there are cases where stable power supply to the auxiliary machinery cannot be achieved due to fluctuations in battery voltage during charging. This includes the first and second cases. The first case occurs when the battery is low in charge and the battery voltage is lower than normal, resulting in a low DC voltage supplied from the charger. The second case occurs when the connection of the cells that make up the battery is switched between series and parallel connection depending on the charge and discharge of the battery.

[0007] The present disclosure has been made to solve the above-mentioned problems, and an object in one aspect is to supply stable power to a group of accessories while a battery is being charged, regardless of the voltage of the battery. [Means for solving the problem]

[0008] A vehicle charging system according to the present disclosure is mounted on a vehicle. The charging system includes a battery that stores power for generating driving force for the vehicle, a first connector to which at least a DC voltage is supplied from an external charger, and a pair of first power lines connecting the battery and the first connector. The charging system also includes a charging circuit that converts AC voltage supplied from the external charger into DC voltage and outputs the DC voltage to the pair of power lines to charge the battery, an auxiliary DC-DC converter that converts the battery voltage input from the pair of power lines and supplies the converted voltage to a group of accessories including at least the auxiliary equipment, a first switching device arranged between the pair of first power lines and the output side of the charging circuit and the input side of the auxiliary DC-DC converter, and a control circuit. The charging circuit includes a power factor correction circuit and a charging DC-DC converter that transforms the DC voltage output from the power factor correction circuit. When predetermined conditions related to battery charging are met, the control circuit opens the first opening / closing device to disconnect the pair of power lines from the output of the charging circuit and the input of the auxiliary DCDC converter, and supplies the DC voltage supplied to the first connector to the charging circuit, activating at least one of the power factor correction circuit and the charging DCDC converter, thereby supplying the DC voltage transformed in the charging circuit to the auxiliary group.

[0009] The charging circuit disclosed herein is mounted on a vehicle equipped with a battery that stores electric power to generate driving force for the vehicle and charges the battery. The vehicle includes: 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 and the first connector; an auxiliary DC-DC converter that converts the battery voltage input from the pair of power lines and supplies the converted voltage to an auxiliary device group including at least the auxiliary devices; and a first switching device disposed between the pair of first power lines and the output side of the charging circuit and the input side of the auxiliary DC-DC converter. The charging circuit includes a power factor correction circuit and a charging DC-DC converter that transforms the DC voltage output from the power factor correction circuit. The charging circuit charges the battery by converting the AC voltage supplied from the external charger into a DC voltage and outputting it to the pair of power lines. When predetermined conditions for charging the battery are met, the charging circuit opens the first opening / closing device, disconnecting the pair of power lines from the output of the charging circuit and the input of the auxiliary DCDC converter, and supplies the DC voltage supplied to the first connector to the charging circuit, activating at least one of the power factor correction circuit and the charging DCDC converter, thereby supplying the DC voltage transformed in the charging circuit to the auxiliary group.

[0010] The control method disclosed herein is a method for controlling voltage in a vehicle. The vehicle includes: a battery that stores power 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 and the first connector; a charging circuit that charges the battery by converting the AC voltage supplied from the external charger into a DC voltage and outputting the DC voltage to the pair of power lines; an auxiliary DC-DC converter that converts the battery voltage input from the pair of power lines and supplies the converted voltage to an auxiliary device including at least the auxiliary devices; and a first switching device arranged between the pair of first power lines and the output side of the charging circuit and the input side of the auxiliary DC-DC converter. The charging circuit has a power factor correction circuit and a charging DC-DC converter that transforms the DC voltage output from the power factor correction circuit. The control method includes, when predetermined conditions related to battery charging are met, opening a first switching device to disconnect a pair of power lines from the output of the charging circuit and the input of the auxiliary DCDC converter, and supplying the DC voltage supplied to the first connector to the charging circuit to operate at least one of the power factor correction circuit and the charging DCDC converter, thereby supplying the DC voltage transformed in the charging circuit to the auxiliary group. [Effects of the Invention]

[0011] According to the present disclosure, stable power can be supplied to the auxiliary machinery group while the battery is being charged, regardless of the voltage of the battery. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram showing the configuration of a vehicle. [Figure 2] 1 is a block diagram of a charging system according to a first embodiment. [Figure 3] 4 is a flowchart of a process performed by an ECU according to the first embodiment. [Figure 4] FIG. 10 is a block diagram of a charging system according to a second embodiment. [Figure 5] 10 is a flowchart of a process performed by an ECU according to a second embodiment. [Figure 6] FIG. 10 is a block diagram of a charging system according to a third embodiment. [Figure 7] FIG. 10 is a block diagram of a charging system according to a fourth embodiment. [Figure 8] FIG. 10 is a block diagram of a charging system according to a fifth embodiment. [Figure 9] FIG. 10 is a block diagram of a charging system according to a sixth embodiment. [Figure 10] FIG. 13 is a block diagram of another charging system according to the sixth embodiment. [Figure 11] FIG. 13 is a block diagram of a charging system according to a seventh embodiment. [Figure 12] FIG. 13 is a block diagram of another charging system according to the seventh embodiment. [Figure 13] FIG. 13 is a block diagram of another charging system according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0014] First Embodiment [Charging system] 1 is a block diagram showing the configuration of a vehicle. A charging system 100 of this embodiment is mounted on a vehicle 1000. The vehicle 1000 is an electric vehicle. In this manner, the charging system 100 is a charging system for the vehicle 1000.

[0015] 2 is a block diagram of charging system 100 according to the present embodiment. Charging system 100 includes ECU 320, a first connector 111, a pair of first power lines 350, an electric load 104, a battery 106, a charging device 300, an auxiliary machinery group 108, an in-vehicle power supply connector 110, and a sensor 107. The pair of first power lines 350 corresponds to the "pair of first power lines" of the present disclosure.

[0016] For example, a charger 113 installed in a charging station is inserted into the first connector 111, and an alternating current (AC) voltage or a direct current (DC) voltage is applied from the charger 113. The ECU 320 can identify whether an AC voltage or a DC voltage is being supplied from the first connector 111. For example, the charger 113 transmits a voltage type signal indicating whether the voltage is an AC voltage or a DC voltage to the ECU 320. The ECU 320 can identify whether the AC voltage or the DC voltage is being charged based on this voltage type signal.

[0017] The battery 106 is a high-voltage battery, for example, a 400V battery. The sensor 107 detects the voltage of the battery 106. The sensor 107 performs detection based on, for example, the SOC (State Of Charge) of the battery 106.

[0018] The charging device 300 includes a charging circuit 180, a DCF (Direct Current Filter) 190, and an auxiliary DDC 200. The charging circuit 180 is typically an on-board charger. The charging circuit 180 converts an AC voltage supplied to the first connector 111 into a DC voltage to charge the battery 106. The auxiliary DDC 200 corresponds to the "auxiliary DCDC converter" of the present disclosure.

[0019] The charging circuit 180 has an OBCACF (On-Board Charger Alternating Current Filter) 152, a PFC (Power Factor Correction) 154, and an isolated DC-DC converter 170. The isolated DC-DC converter 170 includes a primary circuit 156, a transformer 158, and a secondary circuit 160. The isolated DC-DC converter 170 corresponds to the "charging DC-DC converter" of this disclosure.

[0020] The OBCACF 152 suppresses noise transmitted 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 OBCACF 152. The PFC 154 corresponds to the "power factor correction circuit" of the present disclosure. Furthermore, the PFC 154 converts (rectifies) the AC voltage of the AC power with the improved power factor into a DC voltage. The isolated DC-DC converter 170 transforms the DC voltage supplied from the PFC 254. In this embodiment, the transformation is assumed to be "boosting."

[0021] The charging circuit 180 is capable of bidirectional operation. The isolated DC-DC converter 170 of the charging circuit 180 converts the DC voltage supplied from the battery 106, and the PFC 154 converts the DC voltage to an AC voltage (performing a DC / AC conversion operation) and supplies the power to the in-vehicle power supply connector 110. The supplied voltage is, for example, AC 100V for home use.

[0022] The DCF 190 is a filter that suppresses noise in the voltage supplied to the battery 106 and noise in the voltage supplied from the battery 106 .

[0023] The auxiliary DDC 200 supplies power to the auxiliary group 108. The auxiliary group 108 includes at least the auxiliary machines. The auxiliary machines include, for example, the ECU 320, a plurality of opening and closing devices described below, a temperature regulator (not shown) that regulates the temperature of the battery 106, and an in-vehicle air conditioner (not shown). The auxiliary group may also include an auxiliary battery for the auxiliary machines.

[0024] The auxiliary DDC 200 includes an isolated DC-DC converter 210 and a DDC-F (a filter of the auxiliary DDC 200) 212. The isolated DC-DC converter 210 includes a primary circuit 202, a transformer 204, and a secondary circuit 206.

[0025] The pair of first power lines 350 are power lines that connect the first connector 111 and the battery 106. That is, one end of the pair of first power lines 350 is connected to the first connector 111, and the other end of the pair of first power lines 350 is connected to the battery 106. The pair of first power lines 350 is a pair of 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.

[0026] A first node 102A, a second node 102B, and a third node 102C are provided on the pair of first power lines 350. The second node 102B is provided closer to the battery 106 than the first node 102A. The third node 102C is provided closer to the battery 106 than the second node 102B.

[0027] At the first node 102A, a power line branches off from the pair of first power lines 350. The branched power line is connected to an on-board charger alternating current filter (OBCACF) 152 included in the charging circuit 180.

[0028] At the second node 102B, a power line branches off from the pair of first power lines 350. The branched power line is connected to an electric load 104. The electric load 104 is a load that generates driving force for the vehicle 1000 using electric power from the battery 106. The electric load 104 is, for example, a traction inverter.

[0029] At the third node 102C, a power line branches off from the pair of first power lines 350. The branched power line 351 is connected to a DCF (Direct Current Filter) 190 included in the charging device 300. Although not shown in the figure, the power line 351 is connected to both the charging circuit 180 and the auxiliary DDC 200 within the DCF 190.

[0030] The charging system 100 further includes a plurality of switching devices. The plurality of switching devices include a first switching device 301, a second switching device 302, and a third switching device 303. Each 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 disposed between the pair of first power lines 350 and the output side (secondary circuit 160) of the charging circuit 180 and the input side (primary circuit 202) of the auxiliary DDC 200.

[0031] Furthermore, in this disclosure, "opening a switchgear" means "opening both the high-voltage side relay and the low-voltage side relay included in the switchgear." By opening the switchgear, electricity becomes non-conductive (cannot be conducted) at the location of the switchgear. On the other hand, "closing a switchgear" means "closing both the high-voltage side relay and the low-voltage side relay included in the switchgear." By closing the switchgear, electricity becomes conductive (can be conducted) at the location of the switchgear.

[0032] In addition to relays 303H and 303L, third opening / closing device 303 also includes relay 303P connected to a resistor. For example, charging system 100 closes relays 303H and 303P when pre-charging the capacitor of electric load 104 at the start of vehicle 1000. This reduces the amount of current flowing by the amount of the resistor connected to relay 303P, thereby preventing inrush current from flowing to the capacitor.

[0033] The ECU 320 executes control of charging by an external power supply, control of opening and closing of a plurality of opening and closing devices, control of the charging device 300, etc. The ECU 320 corresponds to a "control circuit" in the present disclosure.

[0034] [ECU320 control] Next, the control of ECU 320 will be described. ECU 320 controls the opening and closing of a plurality of opening and closing devices and controls charging device 300. This allows the state of vehicle 1000 (charging system 100) to be switched to one of a plurality of states. The plurality of states include a battery discharging state, an AC charging state, and a DC charging state.

[0035] First, the battery discharge state will be described. The battery discharge state is a state in which the battery 106 is discharged, for example, a state in which the vehicle 1000 is driven (running). The ECU 320 closes the first opening / closing device 301, opens the second opening / closing device 302, and closes the third opening / closing device 303, thereby putting the charging system 100 into the battery discharge state.

[0036] In the battery discharge state, power from the battery 106 is applied to the electrical load 104 and the DCF 190. Furthermore, power is applied from the DCF 190 to the charging circuit 180 and the auxiliary DDC 200. The power from the charging circuit 180 is applied to the in-vehicle power supply connector 110 by the reverse operation of the isolated DC-DC converter 170 and the above-described DC / AC conversion operation of the PFC 154. The voltage applied to the in-vehicle power supply connector 110 is, for example, 100 V AC for home use. Furthermore, power from the auxiliary DDC 200 is applied to the auxiliary group 108.

[0037] Next, the AC charging state will be described. The AC charging state is a state in which the battery 106 is charged by AC voltage supplied from the first connector 111. When the ECU 320 determines that AC voltage is being applied from the charger 113, it opens the second opening / closing device 302 and closes the first opening / closing device 301 and the third opening / closing device 303.

[0038] It is sufficient that either the second switching device 302 or the third switching device 303 is open. However, if both the second switching device 302 and the third switching device 303 are open, it is possible to prevent power from being inadvertently supplied to the electrical load 104.

[0039] In the AC charging state, the AC power supplied from the first connector is applied to the OBCACF 152. The OBCACF 152 suppresses noise input to the charging circuit 180.

[0040] The PFC 154 improves the power factor of the AC power supplied from the OBCACF 152. Furthermore, the PFC 154 converts (rectifies) the AC voltage of the AC power with the improved power factor into a DC voltage. The isolated DC-DC converter 170 transforms the DC voltage supplied from the PFC 154.

[0041] The DCF 190 suppresses noise in the voltage supplied from the isolated DC-DC converter 170. The voltage from the DCF 190 is applied to the auxiliary DDC 200 and the battery 106. As a result, power from the DCF 190 is supplied to the auxiliary DDC 200 and the battery 106. The auxiliary DDC 200 supplies power from the charging circuit 180 (isolated DC-DC converter 170) or the battery 106 to the auxiliary group 108 (auxiliary equipment, auxiliary battery). The auxiliary battery is charged with the supplied power.

[0042] Next, the DC charging (rapid charging) state will be described. When DC charging is performed, ECU 320 acquires the voltage of battery 106 before DC charging, detected by sensor 107. Then, ECU 320 transmits a request signal to charger 113. The request signal is a signal for requesting charger 113 to provide a start voltage when charging of battery 106 with DC voltage starts. The start voltage is the voltage from the timing when charging by charger 113 starts until the timing when a predetermined short time (for example, 3 seconds) has elapsed. The start voltage is also referred to as a start voltage.

[0043] Specifically, when the voltage detected by sensor 107 (the voltage of battery 106 before charging) is equal to or higher than a predetermined value, ECU 320 transmits a request signal to charger 113 to request a higher voltage as the voltage at the start of charging. The predetermined value is a value that is determined in advance.

[0044] Then, ECU 320 closes first opening / closing device 301, second opening / closing device 302, and third opening / closing device 303 and prevents charging circuit 180 from operating for charging. As a result, a sufficient voltage is supplied from charger 113 to battery 106. Furthermore, the potential of third node 102C becomes high. Therefore, the current flowing through the pair of first power lines 350 is branched at third node 102C, and the branched current can be supplied to charging device 300 via the pair of power lines 351. Charging device 300 can pass the current to in-vehicle power supply connector 110 and auxiliary machinery 108. As a result, ECU 320 can supply stable power to in-vehicle power supply connector 110 and auxiliary machinery 108.

[0045] On the other hand, ECU 320 may detect that the voltage detected by sensor 107 is lower than a predetermined value (when the power of battery 106 is depleted). In this case, if DC charging is started at the same voltage as when the voltage detected by sensor 107 is equal to or higher than the predetermined value, a large current tends to flow from charger 113 to battery 106. In this case, if a high voltage is supplied from charger 113 to battery 106, damage to battery 106 may occur.

[0046] Therefore, in order to prevent damage to the battery 106, when the voltage of the battery 106 before charging is lower than the above-mentioned predetermined value, the ECU 320 transmits a request signal to the charger 113 to request a lower voltage from the charger 113. Note that this lower voltage is higher than the voltage of the battery 106 before charging.

[0047] In other words, the start voltage required by the request signal when the voltage of the battery 106 is lower than the predetermined value is lower than the start voltage required by the request signal when the voltage of the battery 106 is higher than the predetermined value. Hereinafter, the control of changing the start voltage depending on the voltage of the battery 106 before charging is also referred to as "voltage control."

[0048] However, if a low voltage is requested from the charger 113, damage to the battery 106 can be suppressed, but sufficient power cannot be supplied to the auxiliary DDC 200. As described above, the auxiliary DDC 200 supplies power to the auxiliary group 108, the ECU 320, the first switching device 301, the second switching device 302, the third switching device 303, and the like. Therefore, if the start voltage from the charger 113 is low, the auxiliary DDC 200 may not be able to supply sufficient power to the auxiliary group 108, the ECU 320, the first switching device 301, the second switching device 302, the third switching device 303, and the like during DC charging of the battery 106.

[0049] Therefore, in the present embodiment, when the voltage detected by the sensor 107 is lower than a predetermined value, the ECU 320 causes the charging circuit 180 to boost the low voltage from the charger 113 and supply it to the accessory DDC 200. Specifically, the ECU 320 opens the first opening / closing device 301 and closes the second opening / closing device 302 and the third opening / closing device 303. Furthermore, the ECU 320 activates the charging circuit 180.

[0050] As a result, the current from the charger 113 flows to the OBCACF 152. Therefore, the DC voltage supplied from the first connector 111 is applied to the OBCACF 152. The OBCACF 152 suppresses noise in the DC voltage.

[0051] The PFC 154 boosts the DC voltage (low voltage) supplied from the OBCACF 152. The PFC 154 is configured as one of a bridge-type PFC circuit, a bridgeless PFC circuit, a totem-pole PFC circuit, etc. Therefore, the PFC 154 is capable of boosting the DC voltage.

[0052] In particular, in this embodiment, charging circuit 180 is capable of supplying household AC 100V to in-vehicle power supply connector 110. Therefore, PFC 154 in charging circuit 180 is configured as a PFC circuit that uses switching elements rather than diodes. The PFC circuit that uses switching elements is, for example, a bridgeless PFC circuit or a totem-pole PFC circuit.

[0053] The isolated DC-DC converter 170 further boosts the boosted DC voltage supplied from the PFC 154 to a voltage at which the auxiliary DDC 200 can operate stably. As described above, in this embodiment, the charging circuit 180, which converts AC voltage to DC voltage during AC charging, functions as a DC voltage transformer circuit (booster circuit) when the voltage of the battery 106 before charging is lower than the predetermined value. In this embodiment, both the PFC 154 and the isolated DC-DC converter 170 in the charging circuit 180 function as transformer circuits (booster circuits). However, as a modified example, either one of the PFC 154 or the isolated DC-DC converter 170 may function as a transformer circuit (booster circuit).

[0054] The DCF 190 suppresses noise in the boosted DC voltage supplied by the isolated DC-DC converter 170. The voltage from the DCF 190 (the voltage generated by the DCF 190) is applied to the auxiliary DDC 200.

[0055] Furthermore, a DC voltage from the first connector 111 is supplied to the battery 106 via the second switching device 302 and the third switching device 303. As a result, power from the DCF 190 is supplied to the auxiliary DDC 200. Note that, because the first switching device 301 is open, the pair of first power lines 350 is disconnected from the output (secondary circuit 160) of the charging circuit 180 and the input (primary circuit 202) of the auxiliary DDC 200. Therefore, it is possible to prevent current from the DCF 190 from flowing to the battery 106 and current from the battery 106 from flowing to the DCF 190.

[0056] Then, the auxiliary DDC 200 supplies the stable electric power from the DCF 190 to the auxiliary group (auxiliary machines, auxiliary battery). The auxiliary battery is charged with the supplied electric power.

[0057] [flowchart] 3 is a flowchart of the processing performed by ECU 320 in this embodiment. First, in step S2, ECU 320 determines whether the supply voltage supplied from charger 113 is an AC voltage or a DC voltage based on a voltage type signal from charger 113. If the supply voltage is an AC voltage (YES in step S2), the processing proceeds to step S4.

[0058] In step S4, ECU 320 closes first opening / closing device 301, opens second opening / closing device 302, and closes third opening / closing device 303. Furthermore, ECU 320 activates charging circuit 180. By executing the process of step S4, ECU 320 can correct the power factor of the AC voltage in charging circuit 180 and convert it into a DC voltage, and supply power to battery 106 and auxiliary DDC 200.

[0059] On the other hand, if the supply voltage is a DC voltage in step S2 (NO in step S2), then in step S6, ECU 320 determines whether the voltage of battery 106 is equal to or higher than a predetermined value. If the voltage of battery 106 is equal to or higher than the predetermined value (YES in step S6), then in step S8, ECU 320 requests a high start voltage from charger 113. Next, in step S10, ECU 320 closes all of first opening / closing device 301, second opening / closing device 302, and third opening / closing device 303. Furthermore, ECU 320 does not operate charging circuit 180 for charging. By executing the process of step S10, ECU 320 can supply power to battery 106 and auxiliary DDC 200.

[0060] On the other hand, if the voltage of battery 106 is less than the predetermined value in step S6 (NO in step S6), ECU 320 requests a low start voltage from charger 113 in step S12. Next, in step S14, ECU 320 opens first opening / closing device 301 and closes second opening / closing device 302 and third opening / closing device 303. Furthermore, ECU 320 activates charging circuit 180. By executing the process of step S14, ECU 320 can charge battery 106 and can supply stable power to auxiliary DDC 200, i.e., auxiliary group 108, even at a low start voltage.

[0061] The condition in step S6 that the voltage of battery 106 is less than the predetermined value (NO in step S6) corresponds to an example of a "predetermined condition related to charging of the battery" in the present disclosure. In other words, when the predetermined condition is met (when NO is determined in step S6), ECU 320 executes the process of step S14.

[0062] [Summary] (1) As described above, in this embodiment, the charging system 100 executes the above-described voltage control (steps S8 and S12) to protect the battery 106. Therefore, damage to the battery 106 can be suppressed. If the voltage of the battery 106 before charging is higher than a 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). This allows a sufficient voltage to be applied to the battery 106 and the auxiliary DDC 200.

[0063] On the other hand, if the voltage of the battery 106 before charging is lower than a predetermined value, the above-described voltage control is executed, and thus a sufficient voltage cannot be applied to the charging device 300. If a sufficient voltage cannot be applied to the charging device 300, a sufficient voltage cannot be applied to the auxiliary DDC 200. If a sufficient voltage cannot be applied to the auxiliary DDC 200, power is supplied to the ECU 320, relays, etc., and therefore power cannot be supplied to the ECU 320, the opening / closing devices (first opening / closing device 301 to third opening / closing device 303), etc. while the battery 106 is being charged, which may cause a problem in that the battery 106 cannot be charged. Furthermore, a problem in that power cannot be supplied to the interior air conditioner and the temperature adjustment device of the battery 106 may occur.

[0064] Therefore, the charging system 100 of this embodiment opens the first switching device 301 and closes the second switching device 302 and the third switching device 303 (step S14). Furthermore, the charging system 100 operates both the PFC 154 and the isolated DC-DC converter 170. This allows the PFC 154 and the isolated DC-DC converter 170 to boost the low voltage from the charger 113 and apply it to the DCF 300. Then, the voltage generated in the DCF 300 (the voltage boosted by the PFC 154 and the isolated DC-DC converter 170) is applied to the auxiliary DDC 200.

[0065] Therefore, while charging the battery 106, the charging system 100 can supply stable power to the auxiliary machinery group 108 regardless of the voltage of the battery 106. In particular, even if the voltage of the battery 106 is lower than a predetermined value, the charging system 100 can charge the battery 106 and supply power to the auxiliary machinery DDC 200. Therefore, the charging system 100 can prevent the above-mentioned problems from occurring.

[0066] In particular, in this embodiment, the charging circuit 180 (particularly the PFC 154 and the isolated DC-DC converter 170) used in AC charging is used as a boost circuit in DC charging. Therefore, the DC voltage from the charger 113 can be transformed without adding a special circuit to the charging device 300. That is, the charging system 100 of this embodiment can use the charging circuit 180 for AC as a circuit for DC. Therefore, the charging system 100 of this embodiment does not need to be provided with a separate charging circuit 180 used in AC charging and a separate boost circuit for DC charging. Therefore, the charging system 100 of this embodiment can reduce the number of parts compared to conventional charging systems.

[0067] (2) Furthermore, when the supply voltage is an AC voltage, the charging system 100 executes the process of step S4, thereby enabling power to be supplied to the auxiliary DDC 200 and the battery 106.

[0068] Second Embodiment 4 shows an example of the configuration of a charging system 100A according to the second embodiment. The battery 106 of the charging system 100A includes a first module 106A and a second module 106B. The first module 106A includes at least one cell. The second module 106B includes at least one cell. The first module 106A and the second module 106B have a voltage of, for example, 400V. The charging system 100A further includes a first switching circuit 400 including a first relay 401, a second relay 402, and a third relay 403.

[0069] One end of the first relay 401 is connected to the negative electrode side of the first module 106A, and the other end of the first relay 401 is connected to the low-voltage power line 350L (the negative electrode side of the second module 106B). One end of the second relay 402 is connected to the negative electrode side of the first module 106A, and the other end of the second relay 402 is connected to the positive electrode side of the second module 106B. One end of the third relay 403 is connected to the positive electrode side of the second module 106B, and the other end of the third relay 403 is connected to the high-voltage power line 350H (the positive electrode side of the first module 106A).

[0070] The first switching circuit 400 is a circuit that switches the state of the charging system 100A between a first state and a second state. The first state is a state in which the first module 106A and the second module 106B are connected in series between the pair of first power lines 350. The second state is a state in which the first module 106A and the second module 106B are connected in parallel to the pair of first power lines 350.

[0071] 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. In both the first state and the second state, the sensor 107 detects the line voltage of the pair of first power lines 350 as the voltage of the battery 106.

[0072] For example, when the vehicle 1000 is driven (when the electric load 104 is operated), the ECU 320 closes the third opening / closing device 303. As a result, power from the battery 106 is supplied to the electric load 104. Furthermore, when the ECU 320 closes the third opening / closing device 303, the ECU 320 sets the first switching circuit 400 to the first state (a state in which the first module 106A and the second module 106B are connected in series). As a result, the charging system 100A can supply a large voltage to the electric load 104 by connecting the first module 106A and the second module 106B in series.

[0073] Furthermore, when the DC voltage supplied to the first connector 111 from the external charger 113 is higher than a predetermined voltage, the ECU 320 sets the state of the first switching circuit 400 to the first state. Here, the predetermined voltage is, for example, 600 V. Furthermore, when the DC voltage supplied to the first connector 111 is higher than the predetermined voltage, for example, the rated voltage of the DC voltage supplied from the charger 113 is 800 V. In other words, this case is when the battery 106 is charged by the charger 113 for an 800 V battery.

[0074] On the other hand, there are cases where the DC voltage supplied from the external charger 113 to the first connector 111 is lower than the predetermined voltage. This case occurs, for example, when the rated voltage of the DC voltage supplied from the charger 113 is 400 V. In other words, this case occurs when the battery 106 is charged by the charger 113 for a 400 V battery.

[0075] When charging with charger 113 for a 400V battery, ECU 320 sets first switching circuit 400 to the second state (a state in which first module 106A and second module 106B are connected in parallel). This allows charging system 100A to charge both first module 106A and second module 106B at a lower voltage than when first module 106A and second module 106B are connected in series.

[0076] By communicating with the charger 113, the ECU 320 can determine whether the DC voltage supplied from the charger 113 is 400V or 800V.

[0077] Also, for example, assume that first module 106A and second module 106B each include 100 cells, and each of the 100 cells is used at 2.5 V to 4.2 V. In this case, when battery 106 is discharging, first module 106A and second module 106B are connected in series, and therefore auxiliary DDC 200 needs to be designed to withstand the application of a voltage of 500 V to 840 V.

[0078] Furthermore, when the battery 106 is being charged, the first module 106A and the second module 106B are connected in parallel, so the auxiliary DDC 200 needs to be designed to withstand the application of voltages from 250 V to 420 V. In other words, the auxiliary DDC 200 must be designed to withstand the application of voltages over a wide voltage range, such as 250 V to 840 V. In conventional auxiliary DDCs, it has been difficult to design the auxiliary DDC 200 to withstand such a wide voltage range when DC charging is performed at 400 V and the voltage of the battery 106 is low.

[0079] In contrast, in the present embodiment, as described below, auxiliary DDC 200 can be designed to withstand voltages in a range of 500 V to 840 V. This voltage range (500 V to 840 V) is the voltage range that can be applied to auxiliary DDC 200 when first module 106A and second module 106B are connected in series (first state).

[0080] This configuration makes it relatively easy to design the auxiliary DDC 200. Furthermore, even when 400V DC charging is performed and the voltage of the battery 106 is lower than a predetermined value due to being in the second state, the charging system 100A boosts the 400V DC charging voltage to a range of 500V to 840V using the charging circuit 180 and supplies the boosted voltage to the auxiliary DDC 200. This ensures that the voltage supplied to the auxiliary DDC 200 falls within the voltage range (500V to 840V) related to the withstand voltage design of the auxiliary DDC 200, while still allowing sufficient power to be supplied to the auxiliary DDC 200 and enabling stable power supply to the auxiliary group 108. Therefore, the voltage range related to the withstand voltage design of the auxiliary DDC 200 can be narrowed.

[0081] In the first embodiment, the predetermined condition for charging the battery includes a condition that the voltage of the battery 106 is lower than a predetermined value. However, in the second embodiment, the predetermined condition may be another condition. The other condition will be described below.

[0082] It is clear that the voltage of the battery 106 varies greatly depending on whether the state of the first switching circuit 400 is the first state or the second state. Therefore, the ECU 320 may be configured to determine that the voltage of the battery 106 is higher than a predetermined value when the state of the first switching circuit 400 is the first state. The ECU 320 may be configured to determine that the voltage of the battery 106 is lower than a predetermined value when the state of the first switching circuit 400 is the second state.

[0083] The predetermined condition may include a condition that the DC voltage supplied to the first connector 111 is lower than a predetermined voltage (600 V) (i.e., a condition that DC charging of 400 V is performed). Fig. 5 is a flowchart of the process performed by the ECU 320 of the second embodiment when such a configuration is adopted.

[0084] 5, step S6 in FIG. 3 is replaced by step S6A, and steps S8 and S12 are not executed. In step S6A, ECU 320 determines whether the DC voltage supplied to first connector 111 is equal to or higher than a predetermined voltage. If the determination in step S6A is YES, ECU 320 executes the process of step S10 without executing the process of step S8. On the other hand, if the determination in step S6A is NO, ECU 320 executes the process of step S14 without executing the process of step S2.

[0085] Furthermore, in step S6A, as indicated in parentheses in step S6A, ECU 320 may determine whether or not the state of first switching circuit 400 is the first state. If the determination in step S6A is YES, ECU 320 executes the process of step S10 without executing the process of step S8. If the determination in step S6A is NO, ECU 320 executes the process of step S14 without executing the process of step S2. The configuration in parentheses in step S6A includes the condition that the state of first switching circuit 400 is the second state.

[0086] Third Embodiment As the first module 106A and the second module 106B in FIG. 4 discharge, the difference between the voltage of the first module 106A and the voltage of the second module 106B may become large. In this case, charging and discharging by the first module 106A and the second module 106B may not be performed properly, and the battery capacity may not be fully utilized. Also, the number of cells in the first module 106A and the second module 106B may differ. In the third embodiment, even if the difference between the voltage of the first module 106A and the voltage of the second module 106B is large, an adjustment circuit that corresponds to the difference is applied.

[0087] 6 shows an example of the configuration of a charging system 100B according to the third embodiment. The charging system 100B is a system in which an adjustment circuit 500 is added to the charging system 100A of FIG.

[0088] The adjustment circuit 500 transforms (boosts or drops) the voltage of the pair of first power lines 350. Then, in the second state, the adjustment circuit 500 applies the transformed voltage to the second module 106B. In Fig. 6, the adjustment circuit 500 is a buck-boost converter that boosts or drops the voltage of the pair of first power lines 350.

[0089] With this configuration, for example, during DC charging, a voltage higher or lower than the voltage applied to the first module 106A can be applied to the second module 106B. Note that the charging system 100B only needs to output a voltage corresponding to the first module 106A from the charger 113. Therefore, even if the difference between the voltages of the first module 106A and the second module 106B is large, the charging system 100B can accommodate this difference. In other words, the adjustment circuit 500 can eliminate voltage imbalances and charge even when the number of cells is different.

[0090] The adjustment circuit 500 is not limited to a step-up / step-down converter, but may be an inverter, a motor, or the like.

[0091] <Fourth embodiment> 7 shows an example of the configuration of a charging system 100C according to a fourth embodiment. The charging system 100C has a second connector 112 in addition to a first connector 111. A DC voltage is applied to the first connector 111 of the charging system 100C. An AC voltage is applied to the second connector 112 of the charging system 100C.

[0092] The charging system 100C also has a second switching circuit 304 for switching the voltage input to the charging device 300 (charging circuit 180), i.e., for 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.

[0093] When a DC voltage is applied and the voltage of the battery 106 is lower than a predetermined value, the ECU 320 switches the second switching circuit 304 to a first state in which the first connector 111 and the charging device 300 are electrically connected. On the other hand, when an AC voltage is applied, the second switching circuit 304 switches to a second state in which the second connector 112 and the charging device 300 are electrically connected. This configuration makes it possible to clearly distinguish between the connector to which the DC voltage is applied and the connector to which the AC voltage is applied. In this way, the concept of the present disclosure is also applicable to a vehicle in which a connector to which the DC voltage is applied and a connector to which the AC voltage is applied are separately provided.

[0094] Fifth Embodiment FIG. 8 shows a configuration example of a charging system 100D according to the fifth embodiment. The charging system 100D further includes a pair of power lines 360. The pair of power lines 360 corresponds to the "pair of second power lines" of the present disclosure. Each of the pair of power lines 360 connects between each of the pair of first power lines 350 and the electrical load 104. Specifically, the pair of power lines 360 includes a high-voltage power line 360H and a low-voltage power line 360L. 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. Furthermore, a third opening and closing device 303 is disposed on the pair of power lines 360.

[0095] Furthermore, when ECU 320 operates electric load 104 (for example, when driving vehicle 1000), it closes third opening / closing device 303. On the other hand, when ECU 320 charges battery 106, it opens third opening / closing device 303.

[0096] According to the charging system 100D, when the electric load 104 is operated, a voltage can be appropriately applied to the electric load 104. On the other hand, when the battery 106 is being charged, the battery 106 and the electric load 104 can be insulated from each other.

[0097] Sixth Embodiment In the above-described embodiment, an example has been described in which the same auxiliary DDC 200 is used whether the battery 106 is discharging or charging. However, a configuration may be adopted in which different auxiliary DDCs are used when the battery 106 is discharging and when the battery 106 is charging.

[0098] 9 shows a configuration example of a charging system 100E according to a sixth embodiment. The charging system 100E employs a configuration in which a voltage can be supplied to the auxiliary DDC 700 from the middle of the charging circuit 180. That is, power can be supplied to the auxiliary DDC 700 from a so-called DC link voltage on the isolated DC-DC converter 170 side of the PFC 154. For example, the auxiliary DDC 700 has the same configuration as the auxiliary DDC 200.

[0099] 9, when a DC voltage is supplied to the first connector 111 and the voltage of the battery 106 is lower than a predetermined value and the battery 106 is being charged, the auxiliary DDC 700 can supply stable power to the auxiliary group 108. On the other hand, when the battery 106 is being discharged, the auxiliary DDC 200 supplies power to the auxiliary group 108.

[0100] Fig. 10 shows another example of the configuration of a charging system 100F according to the sixth embodiment. In the example of Fig. 10, a winding of a secondary circuit 161 separate from the charging circuit 180 is magnetically coupled to the iron core of a transformer 158, so that a voltage can be supplied to the secondary circuit 161. Then, a voltage can be supplied from the secondary circuit 161 to the auxiliary DDC 700.

[0101] Even in a charging system employing such a configuration, the same effects as those of the above-described embodiment can be achieved.

[0102] Seventh Embodiment In the seventh embodiment, another example of Fig. 7 will be described. Fig. 11 shows a configuration example of a charging system 100G as a first example of the seventh embodiment. The second state of the second switching circuit 304 in the charging system 100G is a state in which the second connector 112 and the OBCACF 152 are connected (the state in Fig. 11). The first state of the second switching circuit 304 is a state in which the pair of first power lines 350 (branched power lines 351) and the OBCACF 152 (charging circuit 180) are connected by a power line 362 on the battery 106 side.

[0103] Furthermore, when AC charging is performed, ECU 320 switches second switching circuit 304 to the second state, which enables charging circuit 180 to convert AC voltage into DC voltage and supply it to accessory DDC 200 and battery 106.

[0104] Furthermore, when DC voltage is supplied to the first connector 111 and the voltage of the battery 106 is lower than a predetermined value and the battery 106 is being charged, the ECU 320 switches the second switching circuit 304 to the first state. At the same time, the ECU 320 opens the first opening / closing device 301. As a result, the DC voltage from the first connector 111 is boosted in the charging circuit 180 via the power line 362. Therefore, the charging system 100G boosts the voltage from the battery 106 and supplies it to the auxiliary DDC 200, thereby enabling stable power supply to the auxiliary group 108.

[0105] 12 shows a configuration example of a charging system 100H according to a second example of the seventh embodiment. The second state of the second switching circuit 304 is a state in which the in-vehicle power supply connector 110 and the OBCACF 152 are connected (the state shown in FIG. 12). The first state of the second switching circuit 304 is a state in which the battery 106 and the OBCACF 152 (the charging circuit 180) are connected.

[0106] Furthermore, when the battery 106 is discharged, the ECU 320 switches the second switching circuit 304 to the second state, whereby the OBCACF 152 of the charging circuit 180 supplies the AC voltage to the in-vehicle power supply connector 110.

[0107] Furthermore, when a DC voltage is supplied to the first connector 111 and the voltage of the battery 106 is lower than a predetermined value and the battery 106 is being charged, the ECU 320 switches the second switching circuit 304 to the first state. At the same time, the ECU 320 opens the first opening / closing device 301. As a result, the DC voltage from the first connector 111 is boosted in the charging circuit 180 via the power line 362. Therefore, the charging system 100G boosts the voltage from the battery 106 and supplies it to the auxiliary DDC 200, thereby enabling a stable supply of power to the auxiliary group 108.

[0108] 13 shows a configuration example of a charging system 100I according to a third example of the seventh embodiment. The second state of the second switching circuit 304 is a state (the state shown in FIG. 13) in which the in-vehicle power feeding connector 110 and the OBCACF 152 are connected. The first state of the second switching circuit 304 is a state in which the first connector 111 (DC connector) and the OBCACF 152 (charging circuit 180) are connected.

[0109] Furthermore, when the electric load 104 is operating (for example, when the vehicle 1000 is driving), the ECU 320 switches the second switching circuit 304 to the second state. At the same time, the ECU 320 closes the first opening / closing device 301. As a result, the voltage from the battery 106 is supplied as a DC voltage to the in-vehicle power feeding connector 110 and the auxiliary DDC 200 via the DCF 190.

[0110] Furthermore, when a DC voltage is supplied to the first connector 111, the voltage of the battery 106 is lower than a predetermined value, and the battery 106 is being charged, the ECU 320 switches the second switching circuit 304 to the first state. This causes the charging circuit 180 to boost the DC voltage and supply it to the battery 106 and the auxiliary DDC 200, thereby supplying stable power to the auxiliary group 108.

[0111] Even in a charging system employing such a configuration, the same effects as those of the above-described embodiment can be achieved.

[0112] [Note] (1) A charging system for a vehicle according to the present disclosure is mounted on a vehicle. The charging system includes a battery that stores power for generating driving force for the vehicle, a first connector to which at least a DC voltage is supplied from an external charger, and a pair of first power lines connecting the battery and the first connector. The charging system also includes a charging circuit that converts AC voltage supplied from the external charger into DC voltage and outputs the DC voltage to the pair of power lines to charge the battery, an auxiliary DC-DC converter that converts the battery voltage input from the pair of power lines and supplies the converted voltage to a group of accessories including at least the auxiliary equipment, a first switching device disposed between the pair of first power lines and the output side of the charging circuit and the input side of the auxiliary DC-DC converter, and a control circuit. The charging circuit includes a power factor correction circuit and a charging DC-DC converter that transforms the DC voltage output from the power factor correction circuit. When predetermined conditions related to battery charging are met, the control circuit opens the first opening / closing device to disconnect the pair of power lines from the output of the charging circuit and the input of the auxiliary DCDC converter, and supplies the DC voltage supplied to the first connector to the charging circuit, activating at least one of the power factor correction circuit and the charging DCDC converter, thereby supplying the DC voltage transformed in the charging circuit to the auxiliary group.

[0113] With this configuration, when AC voltage is input from an external charger, the charging circuit converts the AC voltage to DC voltage and outputs it to a pair of power lines to charge the battery. When DC voltage is input from the external charger, the charging circuit activates at least one of the power factor correction circuit and the charging DC-DC converter to transform the DC voltage in the charging circuit and supply the DC voltage to the auxiliary machinery. Therefore, stable power can be supplied to the auxiliary machinery regardless of the battery voltage.

[0114] (2) In the charging system for a vehicle described in (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.

[0115] With this configuration, even if the battery voltage is lower than a predetermined value, the DC voltage transformed by the charging circuit can be supplied to the auxiliary machinery group.

[0116] (3) In a charging system for a vehicle described in (2), the control circuit supplies DC voltage from a pair of first power lines to a group of auxiliary machinery by closing the first opening / closing device when the voltage supplied to the first connector is DC voltage and the battery voltage is higher than a predetermined value.

[0117] With this configuration, when the battery voltage is higher than a predetermined value, the charging circuit does not need to be used for charging, which reduces losses due to the operation of the charging circuit, and can also be used to supply power to the in-vehicle power supply connector by operating the charging circuit in reverse.

[0118] (4) In the vehicle charging system described in (3), when the voltage supplied to the first connector is a DC voltage, the control circuit transmits a request signal to the charger to request a starting voltage for starting charging of the battery with the DC voltage. The control circuit also sets the starting voltage requested by the request signal when the battery voltage is lower than a predetermined value lower than the starting voltage requested by the request signal when the battery voltage is higher than the predetermined value.

[0119] With this configuration, the DC voltage transformed by the charging circuit can be supplied to the auxiliary machinery group, regardless of the battery voltage, while suppressing damage to the battery.

[0120] (5) In the vehicle charging system described in (1), the battery includes a first module including at least one cell and a second module including at least one cell. The vehicle charging system 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 to the pair of first power lines. The predetermined condition includes a condition in which the DC 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.

[0121] With this configuration, the voltage range of the auxiliary DC-DC converter's withstand voltage can be narrowed.

[0122] The control circuit may also set the switching circuit to a first state when the DC voltage supplied to the first connector is higher than a predetermined voltage, and may also set the switching circuit to a second state when the DC voltage supplied to the first connector is lower than the predetermined voltage.

[0123] (6) The vehicle charging system according to (5), further comprising an adjustment circuit that transforms the voltage of the pair of first power lines and applies the transformed voltage to the second module.

[0124] With this configuration, even if the difference between the voltage of the first module and the voltage of the second module is large, the battery can be charged in accordance with the difference.

[0125] (7) The vehicle charging system according to any one of (1) to (6), further comprising a second opening / closing device disposed on the pair of first power lines. The control circuit closes the first opening / closing device and opens the second opening / closing device to operate the charging circuit when the voltage supplied to the first connector is an AC voltage. The control circuit also closes the second opening / closing device when the voltage supplied to the first connector is a DC voltage.

[0126] With this configuration, even if the voltage supplied from the first connector is an AC voltage, the voltage can be applied to the battery and the auxiliary DC-DC converter.

[0127] (8) The vehicle charging system according to any one of (1) to (7), wherein the first connector is supplied with a DC voltage, and the vehicle charging system further includes a second connector to be supplied with an AC voltage.

[0128] With this configuration, it is possible to clearly distinguish between a connector to which a DC voltage is applied and a connector to which an AC voltage is applied.

[0129] (9) A charging system for a vehicle according to any one of (1) to (8), further comprising: an electric load that generates driving force for the vehicle using electric power from the battery; a pair of second power lines that connect the pair of first power lines to the electric load; and a third opening / closing device disposed on the pair of second power lines. The control circuit closes the third opening / closing device when the electric load is operated. The control circuit opens the third opening / closing device when the battery is charged.

[0130] With this configuration, when the battery is discharging, the third opening / closing device is closed, allowing power to be supplied from the battery to the electrical load, and when the battery is charging, the third opening / closing device is opened, preventing unnecessary power from being supplied to the electrical load.

[0131] In addition, since there is a risk that DC voltage may be applied to the terminals of second connector 112 or in-vehicle power supply connector 110 in the circuit configurations of each embodiment, a shutoff function such as an opening / closing device or a switching circuit may be provided in the circuits of OBCACF152 or PFC154 or in the wiring connected to second connector 112 or in-vehicle power supply connector 110.

[0132] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0133] 100, 100A, 100B, 100C, 100D, 100E, 100F charging system, 102A first node, 102B second node, 102C third node, 104 electric load, 106 battery, 106A first module, 106B second module, 107 sensor, 108 auxiliary equipment group, 110 in-vehicle power supply connector, 111 first connector, 112 second connector, 113 charger, 170, 210 isolated DC-DC converter, 180 charging circuit, 300 charging device, 301 first switchgear, 302 second switchgear, 303 third switchgear, 304 second switching circuit, 350 pair of first power lines, 350H high-voltage power line, 350L low-voltage power line, 400 first switching circuit, 401 first relay, 402 Second relay, 403 Third relay, 500 Adjustment circuit, 1000 Vehicle.

Claims

1. A vehicle charging system mounted on a vehicle, a battery that stores electric power 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 and the first connector; a charging circuit that converts AC voltage supplied from an external charger into DC voltage and outputs the DC voltage to the pair of power lines to charge the battery; an auxiliary DC-DC converter that converts the voltage of the battery input from the pair of power lines and supplies the converted voltage to an auxiliary group including at least an auxiliary; a first switching device disposed between the pair of first power lines and an output side of the charging circuit and an input side of the auxiliary DC-DC converter; a control circuit; The charging circuit a power factor correction circuit; a charging DC-DC converter that transforms the DC voltage output from the power factor correction circuit, When a predetermined condition for charging the battery is met, the control circuit opens the first opening / closing device to disconnect the pair of power lines from the output of the charging circuit and the input of the auxiliary DCDC converter, and supplies the DC voltage supplied to the first connector to the charging circuit to operate at least one of the power factor correction circuit and the charging DCDC converter, thereby supplying the DC voltage transformed by the charging circuit to the auxiliary group.

2. 2. The charging system for a vehicle 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. 3. The charging system for a vehicle according to claim 2, wherein the control circuit supplies the DC voltage from the pair of first power lines to the auxiliary machinery group by closing the first opening / closing device when the voltage supplied to the first connector is a DC voltage and the voltage of the battery is higher than the predetermined value.

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

5. The battery a first module including at least one cell; a second module including at least one cell; the vehicle charging system 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 the pair of first power lines and a second state in which the first module and the second module are connected in parallel to the pair of first power lines; 2. The vehicle charging system according to claim 1, wherein 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. 6. The vehicle charging system according to claim 5, further comprising a regulation circuit that transforms a voltage of the pair of first power lines and applies the transformed voltage to the second module.

7. the vehicle charging system further includes a second switching device disposed on the pair of first power lines; The control circuit When the voltage supplied to the first connector is an AC voltage, the first opening / closing device is closed and the second opening / closing device is opened to activate the charging circuit; 7. The charging system for a vehicle according to claim 1, wherein the second opening / closing device is closed when the voltage supplied to the first connector is a DC voltage.

8. The first connector is supplied with a DC voltage, 7. The charging system for a vehicle according to claim 1, further comprising a second connector to which an AC voltage is supplied.

9. The charging system further comprises: an electric load that generates driving force for the vehicle using the electric power of the battery; a pair of second power lines connecting the pair of first power lines to the electrical load; a third switching device disposed on the pair of second power lines, The control circuit When the electric load is operated, the third switching device is closed; 7. The charging system for a vehicle according to claim 1, wherein the third opening / closing device is opened when the battery is to be charged.

10. A charging circuit mounted on a vehicle having a battery that stores electric power to generate driving force for the vehicle, the charging circuit charging the battery, The vehicle is 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 and the first connector; an auxiliary DC-DC converter that converts the voltage of the battery input from the pair of power lines and supplies the converted voltage to an auxiliary group including at least an auxiliary; a first switching device arranged between the pair of first power lines and an output side of the charging circuit and an input side of the auxiliary DC-DC converter; The charging circuit a power factor correction circuit; a charging DC-DC converter that transforms the DC voltage output from the power factor correction circuit, The charging circuit converting AC voltage supplied from an external charger into DC voltage and outputting the DC voltage to the pair of power lines to charge the battery; A charging circuit in which, when a predetermined condition for charging the battery is met, the first opening / closing device opens to disconnect the pair of power lines from the output of the charging circuit and the input of the auxiliary DCDC converter, and supplies the DC voltage supplied to the first connector to the charging circuit, activating at least one of the power factor correction circuit and the charging DCDC converter, thereby supplying the DC voltage transformed by the charging circuit to the auxiliary group.

11. A charging device comprising: the charging circuit according to claim 10; and the auxiliary DC-DC converter.

12. A method for controlling voltage in a vehicle, comprising: The vehicle is a battery that stores electric power 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 and the first connector; a charging circuit that converts AC voltage from an external charger into DC voltage and outputs the DC voltage to the pair of power lines to charge the battery; an auxiliary DC-DC converter that converts the voltage of the battery input from the pair of power lines and supplies the converted voltage to an auxiliary group including at least an auxiliary; a first switching device arranged between the pair of first power lines and an output side of the charging circuit and an input side of the auxiliary DC-DC converter; The charging circuit a power factor correction circuit; a charging DC-DC converter that transforms the DC voltage output from the power factor correction circuit, The control method includes, when a predetermined condition related to charging of the battery is satisfied, opening the first opening / closing device to disconnect the pair of power lines from the output of the charging circuit and the input of the auxiliary DCDC converter, and supplying the DC voltage supplied to the first connector to the charging circuit to operate at least one of the power factor correction circuit and the charging DCDC converter, thereby supplying the DC voltage transformed in the charging circuit to the auxiliary group.

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