Charging device, charging device control method, and program

Abstract

To prevent an increase in the size of components by preventing application of a DC voltage to low-breakdown voltage components during rapid charging without increasing the AC withstand voltage of the components of a charging device.SOLUTION: A charging device includes an input terminal to which either AC power having a first voltage or DC power having a second voltage higher than the first voltage is selectively supplied, a first circuit breaker connected in series to a resistor having one end connected to the input terminal, a resistor and a second circuit breaker connected in parallel to the resistor and the first circuit breaker, an inrush current prevention circuit for preventing inrush current, a power conversion circuit that performs AC / DC conversion of the AC power supplied via the second circuit breaker and outputs it via an output terminal, and a control unit where the first circuit breaker is kept in an open state when no power is supplied to the input terminal, the control unit that maintains the first circuit breaker in the open state when the DC power is supplied to the input terminal.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a charging device, a control method for a charging device, and a program. [Background technology]

[0002] BACKGROUND ART Conventionally, in an on-board charging device that charges a battery from an external power source, a technique is known in which charging is performed via a connector having the same power supply terminal for both an AC power source and a DC power source. In this case, the on-board charging device converts AC power from an AC power source, but it is usually assumed that the voltage of the AC power from the AC power source is lower than the voltage of the DC power from the DC power source.

[0003] For this reason, the components that make up the AC / DC conversion device of the on-board charging device are unable to withstand the voltage of the DC power supplied from the DC power source for rapid charging, so a circuit breaker such as a relay box is used on the vehicle side to prevent the application of high-voltage DC power. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-016276 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the circuit breaker required for the above-mentioned conventional on-board charging device is required to be designed to withstand a large current of up to about 48 A and a voltage of about several hundred volts to 1000 volts.

[0006] As a result, the size of the circuit breaker becomes very large from the viewpoint of voltage resistance performance, and there is a problem that it becomes necessary to provide a communication harness to communicate with the vehicle ECU and the ECU of the vehicle charging device and control the opening and closing timing.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a charging device, a control method for a charging device, and a program that can prevent the application of DC voltage to low-voltage components during rapid charging without increasing the AC withstand voltage of the components of the charging device, thereby preventing the components from becoming larger. [Means for solving the problem]

[0008] The charging device of the present disclosure comprises an input terminal to which either AC power having a first voltage or DC power having a second voltage higher than the first voltage is selectively supplied, a first circuit breaker connected in series to a resistor having one end connected to the input terminal, a resistor and a second circuit breaker connected in parallel to the resistor and the first circuit breaker, an inrush current prevention circuit for preventing inrush current, a power conversion circuit that performs AC / DC conversion of the AC power supplied via the second circuit breaker and outputs it via the output terminal, and a control unit that keeps the first circuit breaker in an open state when no power is supplied to the input terminal and maintains the first circuit breaker in an open state when the DC power is supplied to the input terminal. [Effects of the Invention]

[0009] According to the charging device of the present disclosure, even when AC power and DC power are supplied through the same connector, it is possible to prevent the application of DC voltage to low-voltage components during rapid charging without increasing the AC withstand voltage of the components of the charging device, thereby preventing the components and the on-board charging device from becoming larger. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic explanatory diagram of an electric vehicle charging system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating the principle of the in-vehicle charging device. [Figure 3] FIG. 3 is an explanatory diagram of a first specific example of the configuration of the inrush power prevention circuit and the first circuit breaker. [Figure 4]FIG. 4 is an explanatory diagram of a specific example of an electric vehicle charging system. [Figure 5] FIG. 5 is a flowchart showing the process during normal charging. [Figure 6] FIG. 6 is a flowchart showing the process during rapid charging. DETAILED DESCRIPTION OF THE INVENTION

[0011] FIG. 1 is a schematic explanatory diagram of an electric vehicle charging system according to an embodiment. The electric vehicle charging system 10 of the embodiment includes a charging station 11 , a charging plug 12 , and an electric vehicle 13 . The electric vehicle 13 is equipped with a charging receptacle 14 and an on-board charging device 15 .

[0012] The charging station 11 is configured to receive power from a commercial power source and perform either normal charging, which supplies AC power to the electric vehicle 13 to charge the on-board battery of the electric vehicle 13, or rapid charging, which supplies DC power at a voltage higher than the AC power to the electric vehicle 13 to rapidly supply power to the on-board battery of the electric vehicle 13. In FIG. 1, for the sake of simplicity, it is not made clear whether charging station 11 is configured to perform normal charging or rapid charging, but it is assumed that only either AC power or DC power is supplied depending on which type of charging is being performed. Therefore, the user of the electric vehicle 13 selects a charging station 11 that can perform the corresponding charging based on whether normal charging or rapid charging is desired.

[0013] In this case, the charging plug 12 is connected to a common (identical) input terminal of the charging receptacle 14 of the electric vehicle 13 to be able to supply AC power or DC power, but as described above, it is configured to supply either AC power or DC power, whichever is set in the charging station 11.

[0014] When the charging station 11 is a charging station 11 that performs normal charging, the power supplied via the charging receptacle 14 is AC power, so the on-board charging device 15 of the electric vehicle 13 performs AC / DC power conversion to charge the on-board battery of the electric vehicle 13. Furthermore, when charging station 11 is a charging station 11 that performs rapid charging, the power supplied via charging receptacle 14 is DC power, so in-vehicle charging device 15 cuts off the charging power supply path to prevent the high voltage of DC power from being applied to the power conversion unit, thereby protecting the power conversion unit.

[0015] FIG. 2 is a diagram illustrating the principle of the in-vehicle charging device. The in-vehicle charging device 15 includes input terminals TI1 and TI2, an inrush current prevention circuit 21, a power factor correction circuit (PFC) 22, a smoothing capacitor 23, a DC / DC converter 24, a first circuit breaker 32, and output terminals TO1 and TO2. In the above configuration, input terminals TI1 and TI2 are electrically connected to terminals of charging receptacle 14 to which charging plug 12 is connected and to which power is supplied.

[0016] The inrush current prevention circuit 21 is a circuit that prevents a current for precharging the smoothing capacitor 23 from suddenly flowing in when charging starts. The inrush current prevention circuit 21 includes an inrush current prevention resistor (inrush prevention resistor) 31 and a second circuit breaker 33.

[0017] Here, one end of the inrush current prevention resistor 31 is connected to the input terminal TI1, and when AC power of a predetermined voltage starts to be input from the input terminal TI1, it prevents the current for precharging the smoothing capacitor 23 from being supplied as an inrush current.

[0018] The first circuit breaker 32 is connected in series to the inrush current prevention resistor 31, and one end is connected to the other end of the inrush current prevention resistor 31. When DC power for rapid charging is supplied to the input terminal TI1, the first circuit breaker 32 cooperates with the second circuit breaker 33 to prevent DC power from being supplied to the downstream circuit. Here, the first circuit breaker 32 is a relay.

[0019] The second circuit breaker 33 is connected in parallel to the series-connected inrush current prevention resistor 31 and first circuit breaker 32, and is closed after the smoothing capacitor 23 has been precharged to supply the AC power to be converted to the downstream circuit. Here, the second circuit breaker 33 is a relay. The power factor correction circuit 22 performs control so that the power factor (the ratio of effective power to apparent power) of the AC power supplied from the inrush current prevention circuit 21 approaches unity.

[0020] The smoothing capacitor 23 smoothes the DC voltage output from the power factor correction circuit 22 and operates to supply DC power of a predetermined constant voltage to the circuit at the subsequent stage. The DC / DC converter 24 performs DC / DC conversion based on the voltage of the smoothing capacitor 23 and outputs DC power having a predetermined charging voltage.

[0021] Here, the principle operation of the vehicle-mounted charging device 15 will be described. In this case, in the initial state, the first circuit breaker 32 and the second circuit breaker 33 are in the open state (off state).

[0022] When AC power to be converted is input via the input terminals TI1 and TI2, the first circuit breaker 32 is closed (on state). In this state, the power factor correction circuit 22 is not operating. As a result, the AC power supplied via the input terminals TI1 and TI2 is supplied to the smoothing capacitor 23 with the current amount controlled by the inrush current prevention resistor 31.

[0023] Then, when a time has passed during which the smoothing capacitor 23 is reliably precharged, or when the potential of the smoothing capacitor 23 has increased to a predetermined precharge voltage, the second circuit breaker 33 is switched to a closed state (on state).

[0024] In this state, the power factor correction circuit 22 is transitioned to an operating state, and outputs the power to the smoothing capacitor 23 and the DC / DC converter 24 while controlling the power factor (the ratio of effective power to apparent power) of the AC power supplied from the inrush current prevention circuit 21 to approach 1.

[0025] As a result, the power factor improvement circuit 22 controls the power factor (the ratio of effective power to apparent power) of the AC power supplied from the inrush current prevention circuit 21 to approach 1, while outputting it to the smoothing capacitor 23 and the DC / DC converter 24. Therefore, the DC power converted by the smoothing capacitor 23 and supplied to the DC / DC converter 24 becomes a predetermined constant voltage, enabling power conversion to be performed in a stable state.

[0026] As explained above, when AC power for normal charging is input, the inrush current prevention circuit 21 reliably precharges the smoothing capacitor before transitioning to power conversion operation, thereby enabling stable power conversion operation.

[0027] Furthermore, when a voltage higher than the AC power voltage used for normal charging and rapid charging is input, the inrush current prevention circuit 21 maintains a state in which the supply of DC power to the downstream circuit is cut off, so there is no need to make the withstand voltage of the components that make up the power factor correction circuit 22, smoothing capacitor 23, and DC / DC converter 24 downstream of the inrush current prevention circuit 21 compatible with the DC power voltage, thereby reducing the component costs and the installation area and volume of the components.

[0028] FIG. 3 is an explanatory diagram of a first specific example of the configuration of the inrush power prevention circuit and the first circuit breaker. In FIG. 3, the same parts as those in FIG. 2 are denoted by the same reference numerals. In the example of FIG. 3, relays are used as the first circuit breaker 32A and the second circuit breaker 33A.

[0029] Next, a more specific embodiment will be described. FIG. 4 is an explanatory diagram of a specific example of an electric vehicle charging system. In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the detailed description thereof is to be cited.

[0030] The electric vehicle charging system 10 includes a charging station 11, a charging plug 12, an on-board charging device unit 50, a junction box 51, and an on-board battery 52. Here, the on-board charging device unit 50, the junction box 51, and the on-board battery are mounted on the electric vehicle 13 in FIG.

[0031] As an example of the power supplied by charging station 11, AC power for normal charging is 100 to 200V, and DC power for rapid charging is 400 to 800V. The vehicle-mounted charging device unit 50 includes the vehicle-mounted charging device 15 , an ECU 44 , and a relay 45 .

[0032] The vehicle-mounted charging device 15 includes an inrush current prevention circuit 21, a power factor correction circuit 22, a smoothing capacitor 23, a DC / DC converter 24A, a filter 41, a voltage detection circuit 42, and a filter 43. The filter 41 is a filter that removes noise from the AC power supplied from the charging station 11. The filter 41 does not necessarily have to be provided.

[0033] The voltage detection circuit 42 includes a voltage dividing resistor for outputting a voltage detection signal to the ECU 44 to determine, based on the voltage of the power supplied from the charging station 11, whether the supplied power is AC power for normal charging or DC power for rapid charging.

[0034] The filter 43 is a filter that mainly serves to remove noise caused by the operation of the inrush current prevention circuit 21 . The ECU 44 functions as a controller for controlling the entire in-vehicle charging device 15 .

[0035] When the power supplied from the charging station 11 is DC power for rapid charging, the relay 45 forms a rapid charging current path DCD and supplies DC power directly to the junction box 51 without passing through the on-board charging device 15.

[0036] The junction box 51 switches the current flow path and connects it to the vehicle battery 52 based on whether the DC power supplied via the vehicle charging device unit 50 is DC power obtained by converting AC power via the vehicle charging device 15, or DC current supplied directly from the charging station 11 via the rapid charging current path DCD.

[0037] The on-board battery 53 is charged and discharged under the control of the built-in ECU 52A, stores electric power, or supplies the stored electric power to each part of the electric vehicle 13 or to the outside of the electric vehicle 13.

[0038] Next, the operation during charging of the embodiment will be described. First, a case where the power supplied from charging station 11 is AC power for normal charging will be described.

[0039] FIG. 5 is a flowchart showing the process during normal charging. In the initial state, the first circuit breaker 32A and the second circuit breaker 33 of the inrush current prevention circuit 21 are in the open state, which is the default state (step S11). Also, the relay 45 is assumed to be in the open state, which is the default state.

[0040] In this state, when the ECU 44 is started (step S12), the ECU 44 communicates with the charging station 11 via a communication circuit (not shown) and detects that an AC voltage for normal charging has been applied based on the AC voltage application notification notified or the voltage detected via the voltage detection circuit 42 (step S13).

[0041] When the ECU 44 detects that an AC voltage for normal charging has been applied, the ECU 44 controls the first circuit breaker 32A to be in the on state (closed state) (step S14).

[0042] As a result, the AC power current supplied from charging station 11 via charging plug 12 is supplied to filter 41 via the terminals of charging receptacle 14, where certain noise is removed, and then input to inrush current prevention circuit 21.

[0043] At this time, the first circuit breaker 32A is in a closed state and the second circuit breaker 33 is in an open state, so that the AC power current is input to the power factor correction circuit 22 via the inrush current prevention resistor 31, the first circuit breaker 32A, and the filter 43. Therefore, an excessive inrush current that could damage the filter 43, the power factor correction circuit 22, the smoothing capacitor 23, and the DC / DC converter 24A, which are located downstream of the inrush current prevention circuit 21 in the on-board charging device 15, does not flow.

[0044] Then, the power factor correction circuit 22 outputs AC power to the smoothing capacitor 23 while performing control so that the power factor of the input AC power approaches 1, and an AC voltage is applied (step S15).

[0045] As a result, no inrush current flows through the smoothing capacitor 23, and pre-charging is performed (step S16). Next, the ECU 44 determines whether the pre-charging of the smoothing capacitor 23 is (estimated to be) completed, i.e., whether the time required for the pre-charging of the smoothing capacitor 23 to be completed has elapsed, or whether the potential of the smoothing capacitor 23 has increased to a predetermined pre-charge voltage (step S17). The pre-charge time may be determined based on the capacitance of the electrolytic capacitor behind the applied voltage, the surge protection resistance value, and the applied AC voltage, and may be set to one second, for example.

[0046] If it is determined in step S17 that the precharging of the smoothing capacitor 23 has not yet been completed, that is, the time required for the precharging of the smoothing capacitor 23 to be completed has not elapsed, or the potential of the smoothing capacitor 23 has not yet risen to the predetermined precharge voltage (step S17; No), the process returns to step S15 to continue the precharging of the smoothing capacitor 23.

[0047] In the judgment of step S17, if it is determined that the precharging of the smoothing capacitor 23 has been completed (presumably), that is, if the time required for the precharging of the smoothing capacitor 23 to be completed has elapsed, or if the potential of the smoothing capacitor 23 has risen to a predetermined precharge voltage (step S17; Yes), the second circuit breaker 33 is closed (on) (step S18).

[0048] As a result, the AC power input via the input terminals TI1 and TI2 is supplied to the power factor correction circuit 22 via the second circuit breaker 33.

[0049] The power factor improvement circuit 22 controls the power factor (the ratio of effective power to apparent power) of the AC power supplied from the inrush current prevention circuit 21 so that it approaches 1, while converting it into DC power with voltage fluctuations suppressed by the smoothing capacitor 23 and outputting it to the DC / DC converter 24A.As a result, the DC power supplied to the DC / DC converter 24A has a predetermined constant voltage, enabling power conversion to be performed in a stable state.

[0050] The DC power converted by the DC / DC converter 24 to a voltage suitable for charging the vehicle-mounted battery 52 is supplied to the vehicle-mounted battery 52 via the junction box 51, and normal charging is performed.

[0051] Next, a case where the power supplied from charging station 11 is DC power for rapid charging will be described. FIG. 6 is a flowchart showing the process during rapid charging. In the initial state, the first circuit breaker 32A and the second circuit breaker 33 of the inrush current prevention circuit 21 are in the open state, which is the default state (step S21). Also, the relay 45 is assumed to be in the open state, which is the default state.

[0052] In this state, when the ECU 44 is started (step S22), the ECU 44 communicates with the charging station 11 via a communication circuit (not shown) and detects that an AC voltage for rapid charging has been applied based on the DC voltage application notification notified or the voltage detected via the voltage detection circuit 42 (step S23).

[0053] As a result, the ECU 44 keeps the first circuit breaker 32A in the open state (step S24), so that the smoothing capacitor 23 is not precharged and no DC power is supplied to the filter 43, the power factor correction circuit 22, and the DC / DC converter 24A.

[0054] On the other hand, the ECU 44 closes the relay 45, so that the current is supplied to the vehicle battery 52 via the rapid charging current path DCD and the junction box 51, thereby performing rapid charging.

[0055] As explained above, according to this embodiment, by providing a first circuit breaker in series with the inrush current prevention resistor, even if a configuration is adopted in which AC power for normal charging and DC power for rapid charging, which has a higher voltage than the AC power, are supplied to an electric vehicle via the same terminal of the charging receptacle, the DC power for rapid charging is not supplied to the power conversion circuit (filter, power factor correction circuit, smoothing capacitor, and DC / DC converter) provided to convert the AC power, so there is no need to design the power conversion circuit to withstand high voltage, which reduces the manufacturing costs of the on-board charging device and enables the components to be avoided from becoming larger, thereby reducing the area and volume for installing the components.

[0056] Furthermore, the processes and controls described in the embodiments as being performed by multiple devices may be integrated and realized in one device, and conversely, the processes and controls described as being performed by one device may be configured to be realized by multiple devices working together.

[0057] The ECU (ECU 44 in the example of FIG. 4) functioning as the control unit in the above-described embodiment is equipped with a control device such as an MPU, a storage device such as a ROM (Read Only Memory) or a RAM, and an input device such as an operation switch, and has a hardware configuration using a normal computer.

[0058] The program executed by the ECU (ECU 44 in the example of FIG. 4) that functions as the control unit of this embodiment can also be provided by being recorded in an installable or executable format on a computer-readable recording medium such as a USB memory, a semiconductor storage device such as an SSD, or a DVD (Digital Versatile Disk).

[0059] The program executed by the ECU (ECU 44 in the example of FIG. 4) functioning as the control unit of this embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. The program executed by the ECU (ECU 44 in the example of FIG. 4) functioning as the control unit of this embodiment may be provided or distributed via a network such as the Internet.

[0060] Furthermore, the program for the ECU (ECU 44 in the example of FIG. 4) that functions as the control unit of this embodiment may be provided by being pre-installed in a ROM or the like. [Explanation of symbols]

[0061] 10 Electric vehicle charging systems 11. Charging Station 12 Charging plug 13 Electric Vehicles 14 Charging Receptacle 15 On-vehicle charging device 21 Inrush current prevention circuit 22 Power factor correction circuit 23 Smoothing capacitor 24, 24A DC / DC Converter 31 Inrush current prevention resistor 32, 32A First Circuit Breaker 33, 33A Second circuit breaker 41 Filters 42 Voltage detection circuit 43 Filters 44 ECU 45 Relay 50 On-board charging unit 51 Junction Box 52 Car battery 52A ECU 53 Car Battery DCD Fast charging current path TI1, TI2 input terminals TO1, TO2 output terminals

Claims

1. an input terminal to which either AC power having a first voltage or DC power having a second voltage higher than the first voltage is selectively supplied; a first circuit breaker connected in series to a resistor having one end connected to the input terminal; an inrush current prevention circuit for preventing an inrush current, the inrush current prevention circuit including the resistor and a second circuit breaker connected in parallel to the resistor and the first circuit breaker; a power conversion circuit that performs AC / DC conversion of the AC power supplied via the second circuit breaker and outputs the converted AC power via an output terminal; a control unit that maintains the first circuit breaker in an open state when no power is supplied to the input terminal and maintains the first circuit breaker in an open state when the DC power is supplied to the input terminal; A charging device comprising:

2. the second circuit breaker is in an open state when no power is supplied to the input terminal, The control unit maintains the second circuit breaker in an open state when the DC power is supplied to the input terminal. The charging device according to claim 1 .

3. the power conversion circuit includes a capacitor; When the AC power is supplied to the input terminal, the control unit closes the first circuit breaker to precharge the capacitor, and after a sufficient time has elapsed to precharge the capacitor or when the potential of the capacitor has increased to a predetermined precharge voltage, closes the second circuit breaker, and then opens the first circuit breaker. The charging device according to claim 1 .

4. the control unit closes the second circuit breaker after a sufficient time has elapsed to precharge the capacitor or when the potential of the capacitor has increased to a predetermined precharge voltage, and then opens the first circuit breaker to cause the power conversion circuit to perform AC / DC conversion. The charging device according to claim 3 .

5. The first circuit breaker is configured as a relay. The charging device according to any one of claims 1 to 4.

6. The second circuit breaker is configured as a relay. The charging device according to any one of claims 1 to 4.

7. a first circuit breaker connected in series to a resistor having one end connected to the input terminal, a second circuit breaker connected in parallel to the resistor and the first circuit breaker, and an inrush current prevention circuit for preventing inrush current; and a power conversion circuit that performs AC / DC conversion of the AC power supplied via the second circuit breaker and outputs the converted AC power via an output terminal, the first circuit breaker is in an open state when no power is supplied to the input terminal; determining whether the AC power or the DC power is supplied to the input terminal; maintaining the first circuit breaker in an open state when the DC power is supplied to the input terminal; A control method for a charging device comprising:

8. a first circuit breaker connected in series to a resistor having one end connected to the input terminal, a second circuit breaker connected in parallel to the resistor and the first circuit breaker, and an inrush current prevention circuit for preventing inrush current; and a power conversion circuit for performing AC / DC conversion of the AC power supplied via the second circuit breaker and outputting the converted AC power via an output terminal, the program comprising: the first circuit breaker is in an open state when no power is supplied to the input terminal; The computer a means for determining whether the AC power or the DC power is supplied to the input terminal; a program that functions as a means for maintaining the first circuit breaker in an open state when the DC power is supplied to the input terminal;

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