JP7622546B2 - Charging device and battery warm-up method - Google Patents

Description

This disclosure relates to a charging device that connects to a power grid and converts the supplied power to charge a vehicle battery, as well as a battery warm-up method for warming up a vehicle battery while the battery is being charged by a charging device connected to a power grid.

It is known that as the temperature of a battery drops, overvoltage increases, causing a decrease in battery output during discharge and a decrease in battery capacity during charging. For this reason, there is a demand for technology that can warm the battery appropriately to prevent the battery temperature from dropping excessively.

Patent Document 1 discloses a battery warming system that warms up a battery by controlling the power supply from the main battery to an electric heating means. This battery warming system includes a control device that controls the battery temperature of the main battery by controlling the power supply from the main battery to the electric heating means, and the control device calculates an electric heating output increase amount to be added to the heating request output required of the electric heating means based on the battery temperature of the main battery, the vehicle interior temperature, and the remaining battery charge of the main battery, and sets the value obtained by adding the electric heating output increase amount to the heating request output as an electric heating command value.

JP 2015-080284 A

The technology disclosed in Patent Document 1 controls the temperature of the battery (main battery) to suppress the decrease in battery output. However, in order to warm the battery, the power supply from the battery is increased. Therefore, if applied during charging, charging efficiency decreases. For this reason, it is not suitable as a means of suppressing the decrease in battery capacity during charging.

This disclosure has been made in consideration of the above problems, and aims to provide a charging device and a battery warming method that can warm a battery without using the battery's power when charging the battery.

The charging device according to the first disclosure is a charging device that is connected to a system power supply and converts the supplied power to charge a vehicle battery. This charging device includes a heat transfer structure that transfers heat from the charging device to the battery by coolant liquid, and a control device that controls the current flowing to the charging device. The control device executes a first process that monitors the temperature of the battery, and a second process that increases the current flowing to the charging device when the temperature of the battery is equal to or lower than a predetermined threshold.

The charging device according to the second disclosure further includes the following features compared to the charging device according to the first disclosure.
The charging device further includes a PFC circuit that adjusts the power factor of the power, and a DC-DC converter that is connected to the output side of the PFC circuit and converts the output voltage of the PFC circuit into a charging voltage for the battery. In the second process, the control device increases the current flowing through the charging device by reducing the output voltage of the PFC circuit.

The charging device according to the third disclosure further includes the following features compared to the charging device according to the second disclosure.
In the first process, the control device further monitors the temperature of the coolant and the voltage of the system power supply, and in the second process, the control device determines the output voltage of the PFC circuit in accordance with the temperature of the coolant and the voltage of the system power supply.

The battery warming method according to the fourth disclosure is a battery warming method in which, while the vehicle battery is being charged by a charging device connected to a system power supply, heat from the charging device is transferred to the battery by a coolant liquid to warm the battery. This battery warming method includes a first step of monitoring the temperature of the battery, and a second step of increasing the current flowing to the charging device when the battery temperature is equal to or lower than a predetermined threshold.

The battery warm-up method according to the fifth disclosure further includes the following features compared to the battery warm-up method according to the fourth disclosure.
The charging device includes a PFC circuit that adjusts the power factor of the power, and a DC-DC converter that is connected to the output side of the PFC circuit and converts the output voltage of the PFC circuit into a charging voltage for the battery. The second step includes increasing the current flowing through the charging device by reducing the output voltage of the PFC circuit.

The battery warm-up method according to the sixth disclosure further includes the following features compared to the battery warm-up method according to the fifth disclosure.
The first step further includes monitoring the temperature of the coolant and the voltage of the power supply system, and the second step includes determining an output voltage of the PFC circuit in response to the temperature of the coolant and the voltage of the power supply system.

According to the charging device and battery warming method disclosed herein, heat from the charging device is transferred to the battery by the coolant liquid. Furthermore, when the temperature of the battery falls below a predetermined threshold, the current flowing through the charging device increases. This increases the heat generation of the charging device while the battery is being charged, warming the battery and raising the battery temperature. Furthermore, because the heat generation of the charging device is increased using power from the system power supply, the battery can be warmed without using the power of the battery.

1 is a conceptual diagram showing a charging system to which a charging device according to an embodiment of the present invention is applied. 4 is a conceptual diagram for explaining the operation of the water cooling system when cooling a charging device and a battery. FIG. 4 is a conceptual diagram for explaining the operation of the water-cooling system when warming up the charging device and the battery. FIG. FIG. 2 is a block diagram for explaining a configuration of a charging device. 3 is a block diagram showing a process related to output voltage control of a PFC circuit by a control device. FIG. 6 is a block diagram for explaining an example of a process in the output voltage command value calculation process shown in FIG. 5 . 4 is a flowchart for explaining a battery warm-up method implemented by a charging system to which the charging device according to the present embodiment is applied. FIG. 11 is a block diagram showing an example of processing in an output voltage command value calculation process according to a modified example of the embodiment.

Below, the embodiments of the present disclosure will be described with reference to the drawings. However, when the numbers, quantities, amounts, ranges, etc. of each element are mentioned in the embodiments shown below, the idea of the present disclosure is not limited to the mentioned numbers unless otherwise specified or the number is clearly specified in principle. Furthermore, the configurations, etc. described in the embodiments shown below are not necessarily essential to the idea of the present disclosure unless otherwise specified or the number is clearly specified in principle. In addition, the same reference numerals are used for the same or corresponding parts in each drawing, and duplicate explanations are appropriately simplified or omitted.

1. Charging System The charging device according to this embodiment is applied to a charging system that charges a battery mounted on a vehicle with power supplied from a system power source. Fig. 1 is a conceptual diagram showing a charging system 10 to which a charging device 100 according to this embodiment is applied. However, Fig. 1 shows devices related to charging a battery 200 by the charging system 10 among devices provided in the vehicle 1, and omits other devices. For example, devices (inverter, power control unit, drive motor, etc.) related to a power transmission mechanism that transmits power from the battery 200 to the drive motor of the vehicle 1, and a relay for switching between charging and discharging the battery 200, etc. are omitted.

The vehicle 1 is typically an electric vehicle that runs on power stored in the battery 200 as a power source. Alternatively, the vehicle 1 is a hybrid car that runs on the output of an internal combustion engine and power stored in the battery 200 as a power source. However, the battery 200 can be charged from a power grid 2 external to the vehicle 1. Typically, the vehicle 1 has a charging inlet to which a charging connector that supplies power from the power grid 2 can be connected.

The system power supply 2 is typically an AC power supply. For example, it is a commercial power supply with a voltage of 200 V and a frequency of 50 Hz or 60 Hz.

The charging device 100 is configured to receive power from the power grid 2 and transmit the power to the battery 200. In FIG. 1, the charging device 100 is connected to the power grid 2 via a power transmission path 3a and to the battery 200 via a power transmission path 3b.

The power transmission path 3a typically includes a charging connector that supplies power from the system power supply 2, a charging inlet to which the charging connector is connected, and a cable that connects the charging inlet to the charging device 100. The power transmission path 3b may be a general cable for power transmission.

The charging device 100 converts the power supplied from the system power supply 2 and transmits the converted power to the battery 200, thereby charging the battery 200. Typically, the charging device 100 is an OBC (On Board Charger) provided on the vehicle 1. The charging device 100 includes a power conversion circuit and a control device that executes control related to the power conversion circuit. The configuration of the charging device 100 will be described later.

Battery 200 is typically a rechargeable secondary battery. For example, it is a lithium-ion battery or a nickel-metal hydride battery. Battery 200 is a drive battery that supplies power to a drive motor provided in vehicle 1 during discharge. It is typically a high-voltage battery in which multiple battery cells are connected in series and packaged.

The battery 200 may be configured to be charged by regenerative energy generated when braking the vehicle 1.

Vehicle 1 may be equipped with an auxiliary battery for supplying power to low-voltage devices (such as an ECU (Electronic Control Unit), AC compressor, car navigation system, etc.) equipped in vehicle 1.

The charging system 10 has a water-cooling system for adjusting the temperature of the charging device 100 and the battery 200. The water-cooling system is composed of a coolant liquid, a flow path 4, a water pump 300, a radiator 400, a radiator fan 410, and a thermostat 500. Here, the coolant liquid flows through the flow path 4.

The flow path 4 is typically a hose made of synthetic resin. In FIG. 1, symbols (a, b, ...) are added to the reference numerals to distinguish each part of the flow path 4.

The water pump 300 is a pump for circulating the coolant liquid. Typically, it is a centrifugal pump that drives a rotating member provided on the flow path 4 to circulate the coolant liquid. The water pump 300 pumps the coolant liquid from the flow path 4f toward the flow path 4a (in the direction of the arrow).

The radiator 400 and the radiator fan 410 are devices for dissipating heat from the coolant liquid. The radiator 400 and the radiator fan 410 may be general devices, and dissipate heat from the coolant liquid flowing in the flow path 4d, and direct the dissipated coolant liquid into the flow path 4e.

The thermostat 500 is a device for switching the flow path 4 through which the coolant flows depending on the temperature of the coolant. The thermostat 500 is typically a device in which a member deforms in response to a change in temperature, causing a valve to open and close. However, the thermostat 500 may also be a device that detects the temperature of the coolant and operates electrically.

When the temperature of the coolant is high, the thermostat 500 operates so that the coolant does not flow from flow path 4c to flow path 4f, but flows from flow path 4e to flow path 4f. On the other hand, when the temperature of the coolant is low, the thermostat 500 operates so that the coolant does not flow from flow path 4e to flow path 4f, but flows from flow path 4c to flow path 4f.

However, the thermostat 500 may also operate to vary the ratio between the amount of coolant liquid flowing from flow path 4c to flow path 4f and the amount of coolant liquid flowing from flow path 4e to flow path 4f depending on the temperature of the coolant liquid. In this case, the thermostat 500 operates so that the higher the temperature of the coolant liquid, the greater the amount of coolant liquid flowing from flow path 4e to flow path 4f.

The temperature of the charging device 100 and the battery 200 is adjusted by the coolant passing through the charging device 100 and the battery 200 and heat transfer between the coolant and the charging device 100 and the battery 200. In other words, the charging device 100 and the battery 200 are provided with a structure for passing the coolant flowing through the flow path 4 and transferring heat between the charging device 100 and the battery 200. For example, the charging device 100 is formed of a material with high thermal conductivity such as aluminum, and has a flow path shaped to surround the power conversion circuit. Similarly, the battery 200 is formed of a material with high thermal conductivity and has a flow path shaped to surround the battery cell.

Here, the charging device 100 is equipped with a heat transfer path 110 that allows the coolant liquid that has passed through the charging device 100 to flow to the battery 200. The heat transfer path 110 may have a structure equivalent to that of the flow path 4. After passing through the charging device 100 from the flow path 4a, the coolant liquid travels along the heat transfer path 110 to reach the battery 200. Then, it passes through the battery 200 and flows out into the flow path 4b.

In other words, the charging device 100 has a heat transfer structure that transfers heat from the charging device 100 to the battery 200 via the coolant liquid.

Details of the operation of adjusting the temperature of the charging device 100 and the battery 200 using the water cooling system will be described later.

The charging system 10 is equipped with a plurality of sensors 600. The sensors 600 include a sensor 600a that detects the state of the battery 200, a sensor 600b that detects the temperature of the coolant liquid flowing through the heat transfer path 110, and a sensor 600c that detects the voltage of the system power supply 2. Here, the state of the battery 200 detected by the sensor 600a is the temperature of the battery 200, the battery voltage of the battery 200, etc. However, the sensor 600 may also include other sensors.

The charging device 100 is configured to be able to transmit information to and from these sensors 600. Typically, they are electrically connected by a wire harness. The detection information of these sensors 600 is then transmitted to the charging device 100.

2. Water-cooling system The operation of adjusting the temperature of the charging device 100 and the battery 200 by the water-cooling system will be described below with reference to Figures 2 and 3. Figure 2 shows the operation of the water-cooling system during cooling, and Figure 3 shows the operation of the water-cooling system during warming. In Figures 2 and 3, the arrows indicate the flow of the coolant liquid.

First, the operation of the water-cooling system during cooling will be described with reference to FIG. 2. As shown in FIG. 2, during cooling, the temperature of the coolant is high and the thermostat 500 operates so that the coolant does not flow from flow path 4c to flow path 4f, but flows from flow path 4e to flow path 4f.

As a result, the coolant absorbs heat from the charging device 100 and the battery 200, while dissipating heat in the radiator 400, thereby cooling the charging device 100 and the battery 200.

Next, the operation of the water-cooling system during warm-up will be described with reference to FIG. 3. As shown in FIG. 3, during warm-up, the temperature of the coolant is low and the thermostat 500 operates so that the coolant does not flow from flow path 4e to flow path 4f, but flows from flow path 4c to flow path 4f.

During warm-up, as shown in FIG. 3, the coolant circulates without dissipating heat, and warm-up is achieved by heat generated by the charging device 100 and the battery 200.

When the battery 200 is being charged, the charging device 100 and the battery 200 typically do not generate heat until they require cooling, and are in a warm-up state. At this time, the charging device 100 is operating, and the charging device 100 generates heat due to copper loss and other factors caused by the current flowing through the charging device 100. The heat transfer structure of the charging device 100 transfers the heat of the charging device 100 to the battery 200 via the coolant liquid. In other words, the temperature of the battery 200 increases as the current flowing through the charging device 100 increases and the charging device 100 generates more heat.

The charging device 100 according to this embodiment is characterized in that, when charging the battery 200, if the temperature of the battery 200 is equal to or lower than a predetermined threshold, it operates to increase the current flowing through the charging device 100. As a result, when the temperature of the battery 200 is low, the current flowing through the charging device 100 increases, causing the charging device 100 to generate more heat, and the temperature of the battery 200 can be increased. This in turn allows the battery capacity of the battery 200 to be increased during charging.

4 is a block diagram for explaining the configuration of the charging device 100. The charging device 100 includes a power conversion circuit 120 and a control device 130.

The power conversion circuit 120 includes an AC input filter 121, a PFC circuit 122, a DCDC converter 123, and a DC output filter 124. Here, the AC input filter 121, the PFC circuit 122, the DCDC converter 123, and the DC output filter 124 are connected in series as shown in FIG. 4. The input side of the AC input filter 121 is connected to the system power supply 2, and the output side of the DC output filter 124 is connected to the battery 200.

The AC input filter 121 filters the AC power supplied from the system power supply 2. The AC input filter 121 is composed of, for example, a low-pass filter and a bypass capacitor.

The PFC circuit 122 converts the AC power output from the AC input filter 121 into DC power with an adjusted power factor and suppressed harmonics, and outputs the converted power. The PFC circuit 122 is, for example, composed of a rectifier circuit and a boost chopper circuit. Alternatively, it may be composed of a PWM converter. The PFC circuit 122 includes a switching element, and the power factor and magnitude of the output voltage are controlled by switching control by the control device 130. The switching control by the control device 130 is realized by the switching element of the PFC circuit 122 operating in accordance with a control signal transmitted from the control device 130.

The DC-DC converter 123 is connected to the output side of the PFC circuit 122 and converts the output voltage of the PFC circuit 122 into a charging voltage for the battery 200. The DC-DC converter 123 is composed of, for example, an inverter, a transformer, and a rectifier circuit. The DC-DC converter 123 includes a switching element, and the charging voltage that is the output is controlled by switching control by the control device 130. The switching control by the control device 130 is realized by the switching element of the DC-DC converter 123 operating in accordance with a control signal transmitted from the control device 130.

Here, the smaller the input voltage of the DC-DC converter 123 (the output voltage of the PFC circuit 122), the greater the current flowing through the DC-DC converter 123, and ultimately the current flowing through the charging device 100.

The DC output filter 124 filters the power output from the DC-DC converter 123. The DC output filter 124 is composed of, for example, a common mode filter and a bypass capacitor.

Based on the acquired information, the control device 130 executes control related to the power conversion circuit 120 and outputs a control signal. The information acquired by the control device 130 includes detection information from the sensor 600. However, it may also include other information. For example, it may also include control information of the ECU provided in the vehicle 1 of the battery 200.

Here, the control device 130 acquires detection information related to the state of the battery 200, the temperature of the coolant, and the voltage of the system power supply 2 from the sensor 600 at predetermined intervals, and monitors the temperature of the battery 200, the temperature of the coolant, and the voltage of the system power supply 2 (first process).

The control device 130 is a computer that includes a memory and a processor. The memory stores programs that can be executed by the processor, and data including information acquired by the control device 130 and various information related to the programs. The processor reads the programs from the memory and executes processing according to the programs based on the information in the data read from the memory.

The processing performed by the control device 130, more specifically, the processing performed by the processor according to a program, includes control of the power factor and magnitude of the output voltage of the PFC circuit 122, and control of the battery voltage that is the output of the DCDC converter 123.

Here, the charging device 100 according to this embodiment is characterized by the control of the magnitude of the output voltage of the PFC circuit 122 (hereinafter also simply referred to as "output voltage control"). Details of the output voltage control of the PFC circuit 122 by the control device 130 will be described later. For the control of the power factor of the output voltage of the PFC circuit 122 and the battery voltage that is the output of the DCDC converter 123, appropriate publicly known technology may be adopted depending on the configuration of the PFC circuit 122 and the DCDC converter 123, and detailed explanations will be omitted in this disclosure.

The control device 130 may be a system composed of multiple computers. The processing executed by the control device 130 may be performed according to a combination of multiple programs.

4. Output voltage control of PFC circuit Hereinafter, the output voltage control of the PFC circuit 122 by the control device 130 will be described. Fig. 5 is a block diagram showing a process (second process) related to the output voltage control of the PFC circuit 122 by the control device 130. The output voltage control is made up of a current increase determination process 131, an output voltage command value calculation process 132, and a control signal generation process 133. These processes may be realized as part of a program, or may be realized by a separate computer constituting the control device 130.

The current increase determination process 131 determines whether or not to operate the charging device 100 to increase the current flowing through the charging device 100 in order to raise the temperature of the battery 200, and outputs the determination result. In the current increase determination process 131, when the temperature of the battery 200 (battery temperature) monitored by the control device 130 exceeds a predetermined threshold, it is determined that the current flowing through the charging device 100 is to be increased. Here, the determination result is typically a Boolean value that is 1 when it is determined that the current flowing through the charging device 100 is to be increased, and is 0 when it is determined that the current is not to be increased. Moreover, the predetermined threshold may be given to the program in advance and optimally determined experimentally.

The output voltage command value calculation process 132 calculates and outputs a command value (output voltage command value) for the magnitude of the output voltage of the PFC circuit 122. If the determination in the current increase determination process 131 is negative, the output voltage command value calculation process 132 outputs an output voltage command value to be given as normal operation. On the other hand, if the determination in the current increase determination process 131 is positive, the output voltage command value calculation process 132 outputs an output voltage command value determined according to the temperature of the coolant liquid (coolant liquid temperature) and the voltage of the system power supply 2 (system power supply voltage). An example of the process in the output voltage command value calculation process 132 will be described below with reference to FIG. 6.

First, a voltage value (first voltage value) according to the coolant liquid temperature is calculated based on the first map (132a). The first map is a map that provides a smaller first voltage value the lower the coolant liquid temperature is. In other words, the lower the temperature of the battery 200 is below an appropriate temperature, the greater the output voltage command value that is provided so as to increase the heat generated by the charging device 100. Here, an optimal first map may be adopted. For example, the first map may be a map that provides a first voltage value proportional to the coolant liquid temperature, or a map that provides a first voltage value according to a predetermined function with the coolant liquid temperature as a variable. Alternatively, the first voltage value may be a map that provides a discrete first voltage value with respect to the coolant liquid temperature.

Next, a voltage value (second voltage value) corresponding to the system power supply voltage is calculated based on the second map (132b). The second map is a map that provides a voltage value that can ensure the operation of the PFC circuit 122 (such as power factor adjustment and voltage boosting) for the system power supply voltage. Typically, a lower limit for such a voltage value is provided. However, the second map may be optimally provided in accordance with the characteristics of the PFC circuit 122.

Next, the first voltage value and the second voltage value are compared, and the larger voltage value (voltage command value for increasing current) is calculated (132c). This determines a voltage value that provides sufficient heat generation from the charging device 100 relative to the coolant temperature (temperature of the battery 200) within a range that can ensure the operation of the PFC circuit 122.

Finally, depending on the result of the determination, the voltage command value for current increase or the voltage command value for normal operation is output as the output voltage command value (132d). In other words, if the determination in the current increase determination process 131 is negative, the voltage command value for normal operation is output as the output voltage command value, and if the determination in the current increase determination process 131 is positive, the voltage command value for current increase is output as the output voltage command value.

The normal operation voltage command value here determines the output voltage command value when the charging device 100 is operating normally. Typically, a voltage value large enough to ensure the operation of the PFC circuit 122 is given so that the PFC circuit 122 can operate properly even when the system power supply voltage is high. In other words, the normal operation command value is a value larger than the current increase voltage command value.

Therefore, when the voltage command value for increasing current is used as the output voltage command value, the output voltage of the PFC circuit is lower than when the voltage command value for normal operation is used as the output voltage command value. As a result, the current flowing through the charging device 100 increases, and the heating of the charging device 100 increases.

Refer to FIG. 5 again. The control signal generation process 133 generates a control signal to realize the output voltage command value calculated by the output voltage command value calculation process 132. Typically, switching control of the PFC circuit 122 is performed with the output voltage command value as the target value. Here, the switching control may employ an appropriate known technique depending on the configuration of the PFC circuit 122, and a detailed description thereof will be omitted in this disclosure.

The control signal generated by the control signal generation process 133 is transmitted from the control device 130 to the PFC circuit 122, thereby realizing output voltage control of the PFC circuit 122.

5. Battery Warming-Up Method Hereinafter, a method for warming up the battery 200 implemented by the charging system 10 to which the charging device 100 according to this embodiment is applied will be described with reference to FIG.

Figure 7 is a flowchart for explaining a method for warming up the battery 200 implemented by the charging system 10 to which the charging device 100 according to this embodiment is applied. The process shown in Figure 7 is executed by the charging device 100 during charging, and is executed repeatedly at predetermined intervals.

In step S100, detection information is acquired and the temperature of the battery 200, the temperature of the coolant, and the voltage of the system power supply are monitored (first step). After step S100, the process proceeds to step S110.

In step S110, it is determined whether the temperature of the battery 200 is equal to or lower than a predetermined threshold. If the temperature of the battery 200 is equal to or lower than the predetermined threshold (step S110; Yes), the process proceeds to step S120. If the temperature of the battery 200 is higher than the predetermined threshold (step S110; No), the process proceeds to step S130.

In step S120, the current flowing through the charging device 100 is increased (second step). As described above, this is performed by setting the output voltage of the PFC circuit 122 to the current increasing voltage command value. This increases the heat generated by the charging device 100, and the temperature of the battery 200 can be increased via the heat transfer structure. After step S120, the process ends.

In step S130, the charging device 100 performs normal operation. After step S130, the process ends.

6. Effects As described above, the charging device 100 according to this embodiment has a heat transfer structure that transfers heat from the charging device 100 to the battery 200 by the coolant liquid. Furthermore, the control device 130 provided in the charging device 100 executes a process to increase the current flowing through the charging device 100 when the temperature of the battery 200 falls below a predetermined threshold while the battery 200 is being charged. This increases the heat generated by the charging device 100, and increases the temperature of the battery 200. As a result, the battery capacity of the battery 200 can be increased during charging.

In addition, since the battery 200 is warmed by the heat generated by the charging device 100, the power of the system power source 2 is used, but the power of the battery 200 is not used. Furthermore, since the current flowing through the charging device 100 is increased by controlling the output voltage of the PFC circuit 122, the charging control of the battery 200 can be performed as before by appropriately controlling the output voltage of the DCDC converter 123 according to the output voltage of the PFC circuit 122. In turn, it is possible to suppress a decrease in charging efficiency.

The heat transfer structure of the charging device 100 need only be a structure that can transfer heat from the charging device 100 to the battery 200 by the coolant liquid, and need not be limited to the heat transfer structure described in FIG. 1. For example, a cooling flow path may be provided independently of the heat transfer structure of the charging device 100.

7. Modifications The charging device 100 according to the present embodiment may adopt the following modified aspects. In the following description, matters that overlap with the above-described contents will be omitted as appropriate.

In the output voltage command value calculation process 132, the calculation of the current increasing voltage command value may take into account the battery voltage and the charging power command value of the battery 200. Here, the charging power command value may be calculated by a process executed by the control device 130 based on information such as the charging state and battery voltage of the battery 200. Figure 8 is a block diagram showing an example of the process in the output voltage command value calculation process 132 according to a modified example of this embodiment.

In a modified example of this embodiment, a voltage value (third voltage value) corresponding to the battery voltage and the charging power command value is calculated based on the third map (132e). The third map is a map that provides a voltage value that can satisfy the charging power command value for the battery voltage. Typically, a lower limit of such a voltage value is provided. However, the third map may be optimally provided in accordance with the characteristics of the PFC circuit 122.

In a modified version of this embodiment, the first voltage value, the second voltage value, and the third voltage value are compared, and the larger voltage value is set as the current increase voltage command value (132c).

By adopting such a modified embodiment, even if the current flowing through the charging device 100 is increased, the output voltage of the PFC circuit 122 can be provided within a range that satisfies the charging power command value.

Reference Signs List 1 Vehicle 2 System power supply 10 Charging system 100 Charging device 110 Heat transfer path 120 Power conversion circuit 121 AC input filter 122 PFC circuit 123 DCDC converter 124 DC output filter 130 Control device 200 Battery 300 Water pump 400 Radiator 410 Radiator fan 500 Thermostat 600 Sensor

Claims (6)

A charging device that is connected to a system power supply and converts supplied power to charge a vehicle battery,
a heat transfer structure that transfers heat from the charging device to the battery by a coolant liquid;
A control device for controlling a current flowing through the charging device;
Equipped with
The control device includes:
a first process for monitoring a temperature of the battery;
a second process of increasing a current flowing through the charging device when the temperature of the battery is equal to or lower than a predetermined threshold;
A charging device characterized by performing the above. The charging device according to claim 1,
A PFC circuit that adjusts the power factor of power;
a DC-DC converter connected to an output side of the PFC circuit and configured to convert an output voltage of the PFC circuit into a charging voltage for the battery;
Further equipped with
The control device includes:
The charging device according to claim 1, wherein in the second process, the current is increased by decreasing an output voltage of the PFC circuit. The charging device according to claim 2,
The control device includes:
In the first process,
Furthermore, the temperature of the coolant and the voltage of the power supply system are monitored.
In the second process,
The charging device according to claim 1, wherein an output voltage of the PFC circuit is determined in accordance with a temperature of the coolant and a voltage of the system power supply. 1. A battery warming method for warming a battery of a vehicle by transferring heat from a charging device connected to a system power supply to the battery through a coolant liquid while the battery is being charged by the charging device, comprising:
a first step of monitoring a temperature of the battery;
a second step of increasing a current flowing through the charging device when the temperature of the battery is equal to or lower than a predetermined threshold;
A battery warm-up method comprising: 5. The battery warm-up method according to claim 4,
The charging device is
A PFC circuit that adjusts the power factor of power;
a DC-DC converter connected to an output side of the PFC circuit and configured to convert an output voltage of the PFC circuit into a charging voltage for the battery;
Equipped with
The second step comprises:
a step of increasing the current by reducing an output voltage of the PFC circuit. 6. A battery warm-up method according to claim 5, comprising:
The first step comprises:
further comprising monitoring a temperature of the coolant and a voltage of the power supply system;
The second step comprises:
determining an output voltage of the PFC circuit in accordance with a temperature of the coolant and a voltage of the system power supply.

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