Control device for an electric vehicle

Abstract

The present application aims to prevent power from flowing backward from an electric vehicle to an external power source during AC charging. A control device for an electric vehicle includes a battery, a charging circuit connected to the battery, capable of both AC charging and DC charging, and in which a part of the power lines is shared between the AC charging circuit and the DC charging circuit, and a single charging interface capable of attaching and detaching a charging connector of an external power source, connected to the charging circuit, shared between AC charging and DC charging. In the control device for the electric vehicle, during AC charging control performed in a state in which the charging connector is connected to the charging interface, in a case in which it is determined that a voltage is applied to the AC charging circuit and there is no frequency of the voltage, the AC charging control is stopped.

Description

Technical Field

[0001] This invention relates to a control device for an electric vehicle. Background Technology

[0002] Patent document 1 discloses an electric vehicle that includes a battery, a charging interface, a charging circuit, and a control device. The electric vehicle is externally charged using power supplied from an external power source.

[0003] Patent Document 1: Japanese Patent No. 7524853 Summary of the Invention

[0004] As an electric vehicle capable of external charging, there is a known electric vehicle that has a charging circuit and a charging interface that share both AC and DC charging circuits. However, in this electric vehicle, if a current path is formed in the DC charging circuit during AC charging, electricity may flow backward from the battery to the external power source through the DC charging circuit.

[0005] The present invention was made in view of the above circumstances, and its object is to provide a control device for an electric vehicle that can prevent electricity from flowing back from the electric vehicle to an external power source during AC charging.

[0006] This invention relates to a control device for an electric vehicle, comprising: a battery; a charging circuit connected to the battery, capable of both AC charging and DC charging, wherein a portion of the power lines are shared in both the AC charging circuit and the DC charging circuit; and a single charging interface detachable from an external power supply connector and connected to the charging circuit, shared in both AC charging and DC charging. In the control device for the electric vehicle, during AC charging control performed while the charging connector is connected to the charging interface, if it is determined that a voltage has been applied to the AC charging circuit but the frequency of that voltage does not exist, the AC charging control is stopped.

[0007] Invention Effects

[0008] In this invention, it is possible to prevent electricity from flowing back from the electric vehicle to an external power source during AC charging. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating an electric vehicle in an embodiment.

[0010] Figure 2 It is a diagram used to illustrate the flow of electricity during AC charging.

[0011] Figure 3This is a diagram used to illustrate the method for confirming the status of a system.

[0012] Figure 4 This is a flowchart illustrating the processing flow of AC charging control. Detailed Implementation

[0013] The control device for an electric vehicle according to embodiments of the present invention will now be described in detail. However, the present invention is not limited to the embodiments described below.

[0014] Figure 1 This diagram schematically illustrates an electric vehicle according to an embodiment. The electric vehicle 1 is an electric vehicle capable of external charging using electricity supplied from an external power source. The electric vehicle 1 includes a battery 2, a charging circuit 3, a charging interface 4, and a control device 5.

[0015] Battery 2 is a secondary battery that stores electricity for supplying power to the motor used for driving. Battery 2 is a DC power source installed in the electric vehicle 1. Battery 2 can be charged with power supplied from an external power source.

[0016] Charging circuit 3 is connected to battery 2, converting power supplied from an external power source into charging power suitable for battery 2 and supplying it to battery 2. An SMR6 is installed between charging circuit 3 and battery 2. When SMR6 is closed, battery 2 is electrically connected to charging circuit 3. When SMR6 is open, battery 2 is electrically disconnected from charging circuit 3. SMR6 is controlled by control device 5.

[0017] Charging circuit 3 is capable of both AC charging and DC charging. Charging circuit 3 includes AC charging circuit 7 and DC charging circuit 8. In charging circuit 3, a portion of the power lines are shared between AC charging circuit 7 and DC charging circuit 8. AC charging circuit 7 has an AC charger 9. AC charger 9 is a power conversion device that converts alternating current supplied from an external power source into direct current and outputs it to battery 2. AC charger 9 has an AC / DC conversion section that converts alternating current supplied from the power system into power suitable for charging battery 2. DC charging circuit 8 has a DCR 10. DCR 10 is a charging relay controlled to be in a closed state when charging externally. DCR 10 is controlled by control device 5.

[0018] Charging interface 4 is connected to charging circuit 3 and is a single charging interface shared by both AC and DC charging. Charging interface 4 is electrically connected to battery 2 via charging circuit 3 and SMR6. Charging interface 4 is a shared charging interface that functions as both AC and DC charging interfaces. An AC charging connector can be attached to and removed from charging interface 4, and a DC charging connector can also be attached to and removed from charging interface 4.

[0019] A charging connector 22, which is installed on the charging pile 21, can be attached and detached from the charging interface 4. The charging pile 21 is installed on the power supply equipment 20 and connected to an external power source. The charging connector 22 is connected to the charging pile 21 via a cable 23. The charging pile 21 includes both AC and DC charging piles. The charging connector 22 includes both AC and DC charging connectors. The AC charging connector is connected to the AC charging pile via cable 23. The DC charging connector is connected to the DC charging pile via cable 23. The AC charging pile and AC charging connector are included in a power system that supplies alternating current. The DC charging pile and DC charging connector are included in a power system that supplies direct current.

[0020] Control device 5 is an electronic control device that controls the power supply and charging device. The power supply includes battery 2 and SMR6. The charging device includes charging circuit 3 and charging interface 4. When external charging is performed, control device 5 executes charging control of charging circuit 3. Control device 5 executes charging control by outputting a command signal to SMR6, controlling it to be in a closed state. During the execution of charging control, SMR6 is in a closed state, and battery 2 is electrically connected to charging circuit 3. Charging control includes AC charging control and DC charging control.

[0021] like Figure 2 As shown, AC charging control converts the alternating current supplied from an external power source via charging interface 4 into direct current in AC charging circuit 7 before supplying it to battery 2. DC charging control supplies the direct current supplied from an external power source via charging interface 4 to battery 2 via DC charging circuit 8.

[0022] In the electric vehicle 1 configured as described above, a portion of the power lines of the AC charging circuit 7 and the DC charging circuit 8 are shared in the charging circuit 3. Therefore, if an incorrect energizing path is formed in the DC charging circuit 8 during AC charging, the voltage of the power system will be lower than the voltage of the battery 2, causing reverse current from the battery 2 into the power system. Therefore, the control device 5 correctly detects that AC charging is in progress and is configured to prevent the DC charging circuit 8 from forming during AC charging.

[0023] Control device 5 performs a process to confirm the status of the system connected to charging interface 4. Control device 5 uses a voltage sensor installed on AC charger 9 to confirm the system status. The voltage sensor detects the voltage applied to AC charger 9. The voltage sensor outputs a signal related to the detected voltage to control device 5. Figure 3 As shown, the control device 5 determines the state of voltage and the presence or absence of frequency based on the signal input from the voltage sensor, and determines the state of the system.

[0024] like Figure 3As shown, when checking the voltage status, the control device 5 determines whether the voltage is above a specified value. If the voltage is above the specified value, it is determined that there is voltage. If the voltage is below the specified value, it is determined that there is no voltage. This lack of voltage includes cases where the voltage is below the specified value.

[0025] When confirming the presence or absence of a frequency, control device 5 determines whether a voltage frequency is present. If the voltage frequency is detected, control device 5 determines that a frequency exists. If the voltage frequency cannot be detected, control device 5 determines that no frequency exists.

[0026] If control device 5 determines that there is voltage and frequency, the system is determined to be an AC charging system. If control device 5 determines that there is voltage but no frequency, the system is determined to be a DC charging system. If control device 5 determines that there is no voltage but frequency, the system is determined to be an AC charging system with a low voltage. If control device 5 determines that there is no voltage and no frequency, the charging connector 22 is not connected to the charging interface 4.

[0027] Then, the control device 5 compares the system state obtained from the determination result with the charging state identified by the control device 5. If the system state matches the charging state, charging continues. If the system state does not match the charging state, reverse current may occur from the battery 2 to the external power source, therefore the control device 5 terminates charging.

[0028] Figure 4 This is a flowchart illustrating the processing flow of AC charging control. Figure 4 The control shown is implemented by control device 5.

[0029] Control device 5 detects that the AC charging connector is connected to the charging interface 4 (step S1). In step S1, the AC charging connector is connected to the charging interface 4. Control device 5 detects the connection of the AC charging connector based on signals output from the charging interface 4, etc.

[0030] Control device 5 executes AC charging control (step S2). In step S2, AC charging begins.

[0031] Control device 5 confirms the system status during AC charging (step S3). In step S3, as follows... Figure 3 As shown, the system state is determined. During the execution of AC charging control, the control device 5 determines whether to apply voltage to the AC charger 9 based on the signal input from the voltage sensor of the AC charger 9, and determines whether the voltage frequency is present or absent.

[0032] Control device 5 determines whether the system state is consistent with the control content (step S4). In step S4, it determines whether the system state confirmed by the processing in step S3 is consistent with the AC charging control executed by control device 5. That is, in step S4, it determines whether the system state confirmed in step S3 corresponds to AC charging.

[0033] If the system state is determined to be consistent with the control content (step S4: "Yes"), the control device 5 continues AC charging control (step S5). In this case, AC charging continues. If the processing of step S5 is implemented, the control routine ends.

[0034] If the system state is determined to be inconsistent with the control content (step S4: "No"), the control device 5 terminates AC charging control (step S6). In this case, AC charging is stopped. If step S6 is executed, the control routine ends.

[0035] As explained above, according to the embodiment, the control device 5 can correctly detect that AC charging is in progress and prevents the DC charging circuit 8 from forming a power path during AC charging. This prevents the battery 2's power from flowing back into the power system during AC charging.

[0036] The control device 5 can obtain information from other ECUs as needed to improve the accuracy of the system status determination. For example, when determining the system status, the control device 5 installed in the electric vehicle 1 can consider the charging determination in the HLC-ECU that communicates with the charging pile 21.

[0037] Symbol Explanation

[0038] 1-Electric vehicle, 2-Battery, 3-Charging circuit, 4-Charging interface, 5-Control device, 6-SMR, 7-AC charging circuit, 8-DC charging circuit, 9-AC charger, 10-DCR, 20-Power supply equipment, 21-Charging pile, 22-Charging connector.

Claims

1. A control device for an electric vehicle, comprising: Battery; A charging circuit, connected to the battery, is capable of both AC and DC charging, and a portion of the power lines are shared in both the AC and DC charging circuits; A single charging port, capable of detaching an external power supply charging connector, and connected to the charging circuit, is shared for both AC and DC charging. The control device for the electric vehicle is characterized in that... During the execution of AC charging control while the charging connector is connected to the charging interface, if it is determined that a voltage has been applied to the AC charging circuit but the frequency of the voltage does not exist, the AC charging control is stopped.

2. The control device for an electric vehicle according to claim 1, characterized in that, The AC charging circuit includes an AC charger equipped with a voltage sensor. During the execution of the AC charging control, it is determined whether voltage is applied to the AC charger based on the signal input from the voltage sensor, and the frequency of the voltage is also determined.

3. The control device for an electric vehicle according to claim 1 or 2, characterized in that, The DC charging circuit is electrically connected to the charging connector and to the battery during the AC charging process.

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