Electric vehicle charging controller and charging control method thereof

Abstract

An electric vehicle charging controller (EVCC) according to one embodiment of the present invention comprises: a connection check 1 (CC1) line through which a signal for detecting a connector connection between electric vehicle supply equipment (EVSE) and the electric vehicle charging controller is transmitted; a connection check 2 (CC2) line through which a signal for detecting a connector connection between the EVSE and the electric vehicle charging controller is transmitted; a first voltage detection unit connected to the CC1 line to detect a voltage of the CC1 line; a second voltage detection unit connected to the CC2 line to detect a voltage of the CC2 line; and a control unit which determines that a protective earth (PE) between the EVSE and the electric vehicle charging controller is open if the values detected by the first voltage detection unit and the second voltage detection unit are within a predetermined value, wherein the second voltage detection unit includes a back-to-back field effect transistor (FET) connected to the CC2 line, a positive voltage monitoring circuit, and a negative voltage monitoring circuit.

Description

Electric vehicle charging controller and charging control method thereof

[0001] The present invention relates to an electric vehicle, and more particularly, to a charging controller for an electric vehicle and a charging control method thereof.

[0002] Eco-friendly vehicles such as electric vehicles (EVs) or plug-in hybrid electric vehicles (PHEVs) use electric vehicle supply equipment (EVSE) installed at charging stations to charge their batteries.

[0003] To charge an electric vehicle, the EV and EVSE communicate via a charging connector. Once the charging connector is connected, charging begins after signaling is performed between the EVSE and EV.

[0004] Meanwhile, high voltage current flows between the EVSE and the EV, and when an emergency shutdown is required, a stopping message corresponding to the shutdown reason can be transmitted from the EV to the EVSE.

[0005] If the PE (Protective Earth) line, the grounding wire between the EVSE and the EV, is open, an emergency shutdown is required for safety reasons. Therefore, technology is needed to quickly and accurately detect PE open circuits.

[0006] The technical problem to be achieved by the present invention is to provide an electric vehicle charging controller and a charging control method thereof for quickly and accurately detecting PE (protective earth) open.

[0007] An electric vehicle charging controller (EVCC) according to one embodiment of the present invention includes a CC1 (Connection Check 1) line for transmitting a signal for detecting a connector connection between an Electric Vehicle Supply Equipment (EVSE) and the electric vehicle charging controller, a CC2 (Connection Check 2) line for transmitting a signal for detecting a connector connection between the EVSE and the electric vehicle charging controller, a first voltage detection unit connected to the CC1 line to detect a voltage of the CC1 line, a second voltage detection unit connected to the CC2 line to detect a voltage of the CC2 line, and a control unit for determining that a protective earth (PE) between the EVSE and the electric vehicle charging controller is open when values ​​detected by the first voltage detection unit and the second voltage detection unit are within a predetermined value, and the second voltage detection unit includes a back-to-back FET (back to back field effect transistor), a positive voltage monitoring circuit, and a negative voltage monitoring circuit connected to the CC2 line.

[0008] The above negative voltage monitoring circuit may include a voltage distribution resistor and an operational amplifier (OP Amp).

[0009] The voltage distribution resistor unit includes a first resistor and a second resistor, one end of the first resistor is connected to the CC2 line, and the other end of the first resistor can be connected to one end of the second resistor and the OP Amp.

[0010] The above first resistance may be 100 kΩ or more.

[0011] The above positive voltage monitoring circuit may include a voltage distribution resistor and an OP Amp.

[0012] A signal for detecting a connector connection on the EVSE side can be transmitted through the CC1 line, and a signal for detecting a connector connection on the electric vehicle charging controller side can be transmitted through the CC2 line.

[0013] The above first voltage detection unit may include a voltage distribution resistor unit and an OP Amp.

[0014] The above control unit can estimate the negative voltage of the voltage value detected by the negative voltage monitoring circuit using a pre-stored voltage matching table.

[0015] It may further include an A+ line to which a signal for enabling the electric vehicle charging controller is transmitted, an A- line to which a signal for enabling the electric vehicle charging controller is transmitted, an A+ detection unit for detecting the voltage of the A+ line, and an A- detection unit for detecting the voltage of the A- line.

[0016] The above A+ detection unit and the above A- detection unit may each include a voltage distribution resistor unit and an OP Amp.

[0017] The voltage distribution resistors of the A+ detection unit and the A- detection unit each include a first resistor and a second resistor, one end of the first resistor is connected to the A+ line and the A- line, respectively, and the other end of the first resistor is connected to one end of the second resistor and the OP Amp, and the first resistor may be 100 kΩ or more.

[0018] A charging control method of an electric vehicle charging controller (EVCC) according to an embodiment of the present invention includes a step in which a first voltage detection unit detects a voltage of a CC1 (Connection Check 1) line to which a signal for detecting a connector connection between an Electric Vehicle Supply Equipment (EVSE) and the electric vehicle charging controller is transmitted, a step in which a second voltage detection unit detects a voltage of a CC2 (Connection Check 2) line to which a signal for detecting a connector connection between the EVSE and the electric vehicle charging controller is transmitted, and a step in which a PE (protective earth) between the EVSE and the electric vehicle charging controller is determined to be open when the values ​​detected by the first voltage detection unit and the second voltage detection unit are within a predetermined value, and the second voltage detection unit includes a back-to-back FET (back to back field effect transistor), a positive voltage monitoring circuit, and a negative voltage monitoring circuit connected to the CC2 line.

[0019] According to an embodiment of the present invention, an electric vehicle charging controller that quickly and accurately detects a PE (protective earth) open between an EVSE and an EV can be provided. By using the electric vehicle charging controller according to an embodiment of the present invention, rapid and accurate PE open detection is possible in all cases: when an enable signal is not transmitted from an EVSE-side auxiliary battery; when an enable signal is transmitted from an EVSE-side auxiliary battery but the ground of the EVSE-side auxiliary battery and the ground of the power source are connected; and when an enable signal is transmitted from an EVSE-side auxiliary battery but the ground of the EVSE-side auxiliary battery and the ground of the power source are not connected.

[0020] Figures 1 to 3 are drawings showing a charging system for an electric vehicle according to one embodiment of the present invention.

[0021] FIG. 4 is an example of a pinout of a connection part included in an EVCC according to an embodiment of the present invention.

[0022] Figure 5 is an example of a rapid charging circuit between an EVSE and an EV.

[0023] FIG. 6 is an equivalent circuit diagram of a charging interface between an EVSE and an EVCC according to one embodiment of the present invention.

[0024] FIG. 7 is an equivalent circuit diagram between an EVSE and an EVCC of a CC2 line according to one embodiment of the present invention.

[0025] FIG. 8 is an equivalent circuit diagram between an EVSE and an EVCC of a CC1 line according to one embodiment of the present invention.

[0026] FIG. 9 is an equivalent circuit diagram between the EVSE and EVCC of the A+ line and the A- line according to one embodiment of the present invention.

[0027] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0028] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0029] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0030] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0031] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0032] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

[0033] These terms are intended only to distinguish one component from another, and are not intended to limit the nature, order, or sequence of the component.

[0034] And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, it may include not only cases where the component is directly connected, coupled or connected to the other component, but also cases where the component is 'connected', 'coupled' or 'connected' by another component between the component and the other component.

[0035] Additionally, when described as being formed or arranged "above or below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below", it can include the meaning of a downward direction as well as an upward direction based on one component.

[0036] Hereinafter, embodiments will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or corresponding components are given the same reference numbers, and redundant descriptions thereof will be omitted.

[0037] Figures 1 to 3 are drawings showing a charging system for an electric vehicle according to one embodiment of the present invention.

[0038] Referring to FIGS. 1 to 3, an electric vehicle (EV) 10 can be charged from an electric vehicle supply equipment (EVSE) 20. For this purpose, a charging cable (22) connected to the EVSE (20) can be connected to an inlet of the EV (10). Here, the EVSE (20) is a device that supplies AC or DC, and can be placed at a charging station, placed at home, or implemented to be portable. The EVSE (20) can be used interchangeably with a charging station (supply), an AC charging station (AC supply), a DC charging station (DC supply), a socket-outlet, etc.

[0039] An electric vehicle charging controller (EVCC, 100) is mounted within an EV (10) and connected to the EV (10). For example, the EVCC (100) may be installed within the trunk of the EV (10), but is not limited thereto.

[0040] Here, EVCC (100) can communicate with EV (10) and EVSE (20), respectively.

[0041] According to an embodiment of the present invention, EVCC (100) includes a control unit (110), a connection unit (120), and a detection unit (130).

[0042] The control unit (110) generates a control signal for charging between the EV (10) and the EVSE (20). The control signal for charging generated by the control unit (110) can be transmitted to the EVSE (20) through the connection unit (120) or to the ECU (12) in the EV (10).

[0043] The connection unit (120) is connected to the EVSE (20) and transmits signals between the control unit (110) and the EVSE (20). For example, the connection unit (120) may transmit a charging-related signal received from the EVSE (20) to the control unit (110) and transmit a control signal for charging generated by the control unit (110) to the EVSE (20). In addition, the connection unit (120) transmits power received from the EVSE (20) to the battery (14) in the EV (10) according to the control signal for charging generated by the control unit (110).

[0044] The detection unit (130) detects a charging-related signal between the EV (10) and the EVSE (20). The detection unit (130) is connected to the connection unit (120) and the control unit (110), respectively, and can transmit a value detected from the connection unit (120) to the control unit (110).

[0045] FIG. 4 is an example of a pinout of a connection part included in an EVCC according to an embodiment of the present invention. The pinout illustrated in FIG. 4 may be a shape shown at the end of an EV-side connector.

[0046] Referring to FIG. 4, the connection part (120) may include a total of nine pins. For example, the connection part (120) may include a PE pin, a CC1 pin, a CC2 pin, a DC+ pin, a DC- pin, an A+ pin, an A- pin, an S+ pin, and an S- pin.

[0047] Here, the PE (protective earth) pin is a ground pin and can be a reference for the control line. The PE pin can be included in the grounding wire between the EVSE (20) and the EVCC (100). The CC1 (Connection Check 1) pin and the CC2 (Connection Check 2) pin are pins that transmit and receive signals for detecting the connector connection between the EVSE (20) and the EVCC (100), respectively. The CC1 pin can be a pin that the EVSE (20) recognizes whether the connector between the EVSE (20) and the EVCC (100) is properly connected, and the CC2 pin can be a pin that the EVCC (100) recognizes whether the connector between the EVSE (20) and the EVCC (100) is properly connected. CC can be an abbreviation for Connection Check or Charging Confirmation. The DC- pin and the DC+ pin can be rapid terminals that receive power from the EVSE (20). The A+ pin and the A- pin may be connected to the auxiliary battery of the EVSE (20) to enable the EVCC (100). When the EV (10) is turned off for charging, the A+ pin and the A- pin may be used to enable the EVCC (100). The S+ pin and the S- pin are communication lines for setting operating parameters.

[0048] Meanwhile, the end of the EVSE (20) side connector may also have a shape corresponding to the end of the EV (10) side connector.

[0049] As described above, the EVCC (100) can be mounted within the EV (10). Accordingly, in this specification, the EV (10) side may mean the EVCC (100).

[0050] Fig. 5 is an example of a rapid charging circuit between an EVSE and an EV. The rapid charging circuit between an EVSE and an EV may be a circuit diagram in which an end of a connector on the EV (10) side and an end of a connector on the EVSE (20) side are connected.

[0051] Referring to FIG. 5, the rated voltage for rapid charging between the EVSE and the EV may be 750 V to 1000 V, the rated current may be 80 A / 125 A / 200 A / 250 A, and the maximum power may be 250 kW. The circuit for rapid charging between the EVSE and the EV may be composed of three high-voltage lines and six signal lines. Here, the high-voltage lines may be a DC+ line, a DC- line, and a PE line connected between the EVSE (20) and the battery of the EV (10). In addition, the signal lines may be an A+ line and an A- line for enabling the EVCC (100), a CC1 line and a CC2 line for recognizing whether the connector between the EVSE (20) and the EVCC (100) is properly connected, and an S+ line and an S- line for exchanging data through CAN communication between the EVSE (20) and the EVCC (100).

[0052] The charging process is controlled by signals transmitted between the EVSE (20) and the EVCC (100) through the S+ line and the S- line. The charging process may include handshake initiation and recognition, amperage and voltage configuration, charging and suspension of charging. In the first handshake step, the S+ / S- communication lines between the EVSE (20) and the EVCC (100) are connected, and the A+ / A- auxiliary battery lines are connected. The EVSE (20) transmits a handshaking signal to the EVCC (100) to confirm the connection of the S+ / S- communication lines, and if the EVCC (100) responds positively, the EVSE (20) starts insulation monitoring and then sends an appropriate insulation safety message to the EVCC (100). If the EVCC (100) confirms the insulation safety message, the EVSE (20) and the EVCC (100) start the next charging parameter configuration step. In this step, the EVCC (100) sends the battery charging parameters to the EVSE (20), and the EVSE (20) responds with the maximum output capacity. After the EVCC (100) confirms this message, the EVCC (100) evaluates whether the EV (10) meets the charging conditions and then sends a message indicating that the EVCC (100) is ready. When the ready signal of the EVCC (100) is confirmed, the EVSE (20) checks whether the EVSE (20) is ready and sends the EVSE (20) ready signal back to the EVCC (100). After the EVCC (100) confirms the EVSE (20) ready signal, the next charging step begins. In this step, the EVCC (100) sends a charge start signal and the current battery status to the EVSE (20). The EVSE (20) adjusts the output current according to a continuous feedback loop until the EVCC (100) or the EVSE (20) sends a charge stop message.

[0053] Meanwhile, according to an embodiment of the present invention, the detection unit (130) detects a PE (protective earth) open between the EV (10) and the EVSE (20). Here, PE refers to a grounding wire of a high-voltage line between the EVCC (100) and the EVSE (20), and PE open refers to a state in which the grounding wire of the high-voltage line between the EVCC (100) and the EVSE (20) is disconnected. In this specification, PE open may also be referred to as a broken PE.

[0054] In an embodiment of the present invention, a circuit diagram of a charging interface between an EVSE and an EV is changed to implement a fast and accurate PE open structure.

[0055] FIG. 6 is an equivalent circuit diagram of a charging interface between an EVSE and an EVCC according to one embodiment of the present invention, FIG. 7 is an equivalent circuit diagram between an EVSE and an EVCC of a CC2 line according to one embodiment of the present invention, FIG. 8 is an equivalent circuit diagram between an EVSE and an EVCC of a CC1 line according to one embodiment of the present invention, and FIG. 9 is an equivalent circuit diagram between an EVSE and an EVCC of an A+ line and an A- line according to one embodiment of the present invention.

[0056] Referring to Fig. 6, a circuit for charging between the EVSE (20) and the EV (10) may be composed of three high-voltage lines and six signal lines. Here, the high-voltage lines may be a DC+ line, a DC- line, and a PE line connected between the battery of the EVSE (20) and the EV (10). In addition, the signal lines may be connected to the auxiliary battery of the EVSE (20), and may be an A+ line and an A- line for enabling the EVCC (100), a CC1 line and a CC2 line for recognizing whether the connector between the EVSE (20) and the EVCC (100) is properly connected, and an S+ line and an S- line for exchanging data through CAN communication between the EVSE (20) and the EVCC (100).

[0057] The CC1 line may be a line through which a signal is transmitted for the EVSE (20) to recognize whether the connector between the EVSE (20) and the EVCC (100) is properly connected, and the CC2 line may be a line through which a signal is transmitted for the EVCC (100) to recognize whether the connector between the EVSE (20) and the EVCC (100) is properly connected. The connection status of the EVSE (20) may be confirmed through the CC1 line, and the connection status of the EVCC (100) may be confirmed through the CC2 line. CC may be an abbreviation for Connection Check or Charging Confirmation.

[0058] According to an embodiment of the present invention, in order to wake up the CC1 line, the CC1 line may be connected to the EVCC (100). For this purpose, an additional pin for the CC1 signal may be further arranged in the connector between the EVSE (20) and the EVCC (100). Although not shown, a switch for the CC1 line may be further arranged in the connector between the EVSE (20) and the EVCC (100).

[0059] According to an embodiment of the present invention, the EVCC (100) may further include a switch (S2) and a resistor (R6) connected between the CC1 line and the PE line. The switch (S2) may be connected in series between the CC1 line and the PE line, while the resistor (R6) may be connected in parallel to the switch (S2).

[0060] And, according to an embodiment of the present invention, a switch (S3) may be further placed between the CC2 line and the power supply (U2) of the EVCC (100).

[0061] In a charging scenario, switch (S3) is opened before the charging process begins. In a normal state, the voltage at detection point (DP 2) is detected as 0 V, and the voltage at DP 3 can be detected as 4 V. Accordingly, switches (S1) and (S2) are turned on, and the charging state is enabled.

[0062] Meanwhile, if the EVCC (100) determines that an emergency shutdown is required, a stop message corresponding to the shutdown reason may be transmitted. If the emergency shutdown is triggered during the output circuit detection phase and the subsequent phase, the switch S2 will be opened, and if the emergency shutdown is triggered before the output circuit detection phase, the switch S2 will not be opened. The reasons for triggering the EVCC (100) to enter the emergency shutdown state are: a) if the switch S1 is opened by the EVSE (20), then the voltage at the detection point (DP) 3 between the CC1 line and the control unit (110) of the EVCC (100) becomes 2 V; b) if the vehicle connector is disconnected, then the voltage at the detection point (DP) 3 between the CC1 line and the control unit (110) of the EVCC (100) becomes 0 V; c) If a broken PE of the vehicle connector occurs during charging, the voltage at detection point (DP) 2 between the CC2 line and the control unit (110) of the EVCC (100) becomes -12 V when the switch S3 is open, and the voltage at detection point (DP) 3 between the CC1 line and the control unit (110) of the EVCC (100) becomes 0 V.

[0063] That is, when PE is opened during charging, the voltage at DP 2 changes from 0 V to -12 V, and the voltage at DP3 changes from 4 V to 0 V.

[0064] According to one embodiment of the present invention, it is intended to detect PE open quickly and accurately by detecting voltage changes in the CC2 line and the CC1 line.

[0065] According to an embodiment of the present invention, the detection unit (130) of the EVCC (100) includes a first voltage detection unit (600) connected to the CC1 line to detect the voltage value of the CC1 line and a second voltage detection unit (610) connected to the CC2 line to detect the voltage value of the CC2 line. Here, the second voltage detection unit (610) may include a negative voltage monitoring circuit (612) that monitors the negative voltage of the CC2 line and a positive voltage monitoring circuit (614) that monitors the positive voltage of the CC2 line.

[0066] And, the control unit (120) of the EVCC (100) includes a CC1 MCU (600M) that generates a charging control signal using the detection value of the CC1 detection unit (600) and a CC2 MCU (610M) that generates a charging control signal using the detection value of the CC2 detection unit (610). The CC1 MCU (600M) generates a charging control signal using the detection value of the positive voltage monitoring circuit of the CC1 line. The CC2 MCU (610M) may include a CC2 negative voltage monitoring MCU (612M) that generates a charging control signal using the detection value of the negative voltage monitoring circuit (612) of the second voltage detection unit (610) and a CC2 positive voltage monitoring MCU (614M) that generates a charging control signal using the detection value of the positive voltage monitoring circuit (614) of the second voltage detection unit (610). Although the CC1 MCU (600M), CC2 negative voltage monitoring MCU (612M), and CC2 positive voltage monitoring MCU (614M) are illustrated as independent MCUs, they are not limited thereto, and the CC1 MCU (600M), CC2 negative voltage monitoring MCU (612M), and CC2 negative voltage monitoring MCU (614M) may be implemented as a single integrated MCU. Although not illustrated, a circuit for waking up the CC2 line may be further arranged on the CC2 line, and a circuit for waking up the CC1 line may be further arranged on the CC1 line.

[0067] According to an embodiment of the present invention, when the voltage value of the CC1 line detected by the first voltage detection unit (600) and the voltage value of the CC2 line detected by the negative voltage monitoring circuit (612) of the second voltage detection unit (610) are within a predetermined value, it is determined that the PE (protective earth) between the EVSE (20) and the EVCC (100) is open. More specifically, when the voltage value of the CC1 line detected by the first voltage detection unit (600) is 0 V and the voltage value of the CC2 line detected by the negative voltage monitoring circuit (612) of the second voltage detection unit (610) is -12 V, it is determined that the PE (protective earth) between the EVSE (20) and the EVCC (100) is open. Here, the voltage value of the CC1 line and the voltage value of the CC2 line may include a predetermined error. For example, if the voltage value of the CC1 line detected by the first voltage detection unit (600) is about 0 V and the voltage value of the CC2 line detected by the negative voltage monitoring circuit (612) of the second voltage detection unit (610) is about -12 V, it can be determined that the PE (protective earth) between the EVSE (20) and the EVCC (100) is open. For example, if the voltage value of the CC1 line detected by the first voltage detection unit (600) is 0 V to 0.5 V and the voltage value of the CC2 line detected by the negative voltage monitoring circuit (612) of the second voltage detection unit (610) is -11.5 V to -12.5 V, it can be determined that the PE (protective earth) between the EVSE (20) and the EVCC (100) is open.

[0068] To this end, according to an embodiment of the present invention, the second voltage detection unit (610) includes a negative voltage monitoring circuit (612), a positive voltage monitoring circuit (614), and a dual FET (616) connected to the CC2 line. Here, the dual FET (616) may include two FETs connected back to back. Accordingly, in the present specification, the dual FET (616) may also be referred to as a back to back FET. The back to back FET is arranged between the first node (N1) of the CC2 line and DC 12 V. The back to back FET is a system in which two FETs are connected in series with each other, but their body diodes are connected in opposite directions to block bidirectional current flow. When back-to-back FETs are placed between the first node (N1) of the CC2 line and DC 12 V, current flow through the CC2 line in the direction from the EVSE (20) toward the EVCC (100) is possible, but current flow through the CC2 line in the direction from the EVCC (100) toward the EVSE (20) is blocked.

[0069] According to an embodiment of the present invention, a negative voltage monitoring circuit (612) is connected to a first node (N1) of the CC2 line. The negative voltage monitoring circuit (612) may include a voltage-dividing resistor unit and an OP Amp (X1). Here, the voltage-dividing resistor unit may be disposed between the first node (N1) of the CC2 line and the OP Amp (X1) to distribute the voltage input to the OP Amp (X1). For example, the voltage-dividing resistor unit may include a first resistor (Ra) and a second resistor (Rb), one end of the first resistor (Ra) may be connected to the first node (N1) of the CC2 line, and the other end of the first resistor (Ra) may be connected to one end of the second resistor (Rb) and the OP Amp (X1). At this time, the first resistor (Ra) may be 100 kΩ or more, preferably 100 kΩ or more and 1000 kΩ or less, and more preferably 100 kΩ or more and 500 kΩ or less. At this time, the first resistance (Ra) may be more than twice the second resistance (Rb). In this way, if the first resistance (Ra) of the voltage distribution resistor is designed to be 100 kΩ or more, a structure capable of accurately detecting a voltage value can be obtained without electrically affecting the peripheral circuit and without placing a load on the MCU by reducing the current flow through the CC1 line when PE is opened.

[0070] According to an embodiment of the present invention, the negative voltage monitoring circuit (612) may further include a diode (D3) disposed between the voltage-dividing resistor and the OP Amp (X1). The cathode of the diode (D3) may be connected to the voltage-dividing resistor, and the anode may be connected to the OP Amp (X1). Accordingly, the flow of current from the OP Amp (X1) toward the voltage-dividing resistor is blocked, and the negative voltage of the CC2 line can be easily monitored.

[0071] Meanwhile, the CC2 negative voltage monitoring MCU (612M) is connected to the negative voltage monitoring circuit (612), and if the voltage value detected by the negative voltage monitoring circuit (612) is within a predetermined value, it determines that the PE (protective earth) between the EVSE (20) and the EVCC (100) is open. For example, if -12 V is detected by the CC2 negative voltage monitoring MCU (612M), it can be determined that the PE is open.

[0072] To this end, the CC2 negative voltage monitoring MCU (612M) can store in advance a voltage matching table for estimating the negative voltage using the voltage value detected by the negative voltage monitoring circuit (612).

[0073] Meanwhile, according to an embodiment of the present invention, the positive voltage monitoring circuit (614) may also include a voltage-dividing resistor unit and an OP Amp (X2). Here, the voltage-dividing resistor unit may be arranged between the first node (N1) of the CC2 line and the OP Amp (X2) to distribute the voltage entering the OP Amp (X2). For example, the voltage-dividing resistor unit may include a first resistor (Rc) and a second resistor (Rd), one end of the first resistor (Rc) may be connected to the first node (N1) of the CC2 line, and the other end of the first resistor (Rc) may be connected to one end of the second resistor (Rd) and the OP Amp (X2). At this time, the first resistor (Rc) may be 100 kΩ or more, preferably 100 kΩ or more and 1000 kΩ or less, and more preferably 100 kΩ or more and 500 kΩ or less. According to an embodiment of the present invention, if the positive voltage monitoring circuit (614) includes a voltage distribution resistor, the control unit (120) can also detect a high voltage value of 12 V or more and 16 V or less applied to the input line. In addition, if the voltage distribution resistor of the positive voltage monitoring circuit (614) includes a high first resistor (Rc) of 100 kΩ or more, the electrical influence of the positive voltage monitoring circuit (614) on the CC2 line can be minimized by reducing the current flow when PE is open, thereby increasing the accuracy of negative voltage detection of the CC2 line. The connection status and charging status of the EVCC (100) can be monitored using the voltage value detected by the positive voltage monitoring circuit (614).

[0074] As illustrated in FIGS. 6 to 8, a negative voltage monitoring circuit (612), a positive voltage monitoring circuit (614), and a dual FET (616) may be connected to the first node (N1) of the CC2 line. Accordingly, in a normal state, a signal for connector connection detection is transmitted in the direction from the EVSE (20) toward the EVCC (100) through the dual FET (616), and the signal for connector connection detection may be detected by the positive voltage monitoring circuit (614). In addition, when the switch S3 is opened and the PE is opened in a charging state, a negative voltage applied to the CC2 line may be detected by the negative voltage monitoring circuit (612).

[0075] According to an embodiment of the present invention, the CC1 detection unit (600) detects the voltage value of the CC1 line. The CC1 MCU (600M) estimates the voltage value of the CC1 line using the result value of the CC1 detection unit (600), and the connection status and charging status of the EVSE (20) can be monitored according to the voltage value of the CC1 line. If the voltage value of the CC1 line is within a predetermined range, it is determined that the PE (protective earth) between the EVSE (20) and the EVCC (100) is open. For example, if the CC1 MCU (600M) detects 0 V, it can be determined that the PE is open.

[0076] To this end, the CC1 detection unit (600) may include a voltage-dividing resistor unit and an OP Amp (X3). Here, the voltage-dividing resistor unit may be arranged between the second node (N2) of the CC1 line and the OP Amp (X3) to distribute the voltage entering the OP Amp (X3). For example, the voltage-dividing resistor unit may include a first resistor (Re) and a second resistor (Rf), one end of the first resistor (Re) may be connected to the second node (N2) of the CC1 line, and the other end of the first resistor (Re) may be connected to one end of the second resistor (Rf) and the OP Amp (X3). At this time, the first resistor (Re) may be 100 kΩ or more, preferably 100 kΩ or more and 1000 kΩ or less, and more preferably 100 kΩ or more and 500 kΩ or less.

[0077] According to an embodiment of the present invention, if the voltage distribution resistor of the CC1 detection unit (600) includes a high first resistance of 100 kΩ or more, the current flow to the CC1 line may be reduced when PE is opened.

[0078] Meanwhile, according to an embodiment of the present invention, an A+ detection unit (620) for detecting the voltage of an A+ line through which a signal for enabling the EVCC (100) is transmitted, and an A- detection unit (630) for detecting the voltage of an A- line through which a signal for enabling the EVCC (100) is transmitted may be further included. For example, when a value detected by the A+ detection unit (620) or the A- detection unit (630) is greater than or equal to 0.5 V, it may be determined that an enable signal has been transmitted. Depending on the specifications of the EVSE (20) or the EVCC (100), when the EVCC (100) operates in a low power mode, it may be triggered by the A+ line and the A- line connected to the auxiliary battery of the EVSE (20), and there is a need to detect the voltages of the A+ line and the A- line. However, when detecting the voltages of the A+ line and the A- line, the circuit for implementing this may affect the detection performance of the first voltage detection unit (600) for detecting the voltage of the CC1 line and the second voltage detection unit (610) for detecting the voltage of the CC2 line. Accordingly, it is necessary to design the A+ detection unit (620) and the A- detection unit (630) so as not to affect the performance of the first voltage detection unit (600) for detecting the voltage of the CC1 line and the second voltage detection unit (610) for detecting the voltage of the CC2 line.

[0079] As illustrated in FIG. 9, the A+ detection unit (620) may include a voltage-dividing resistor unit and an OP Amp (X4). Here, the voltage-dividing resistor unit may be arranged between the third node (N3) of the A+ line and the OP Amp (X4) to distribute the voltage entering the OP Amp (X4). For example, the voltage-dividing resistor unit may include a first resistor (Rg) and a second resistor (Rh), one end of the first resistor (Rg) may be connected to the third node (N3) of the A+ line, and the other end of the first resistor (Rg) may be connected to one end of the second resistor (Rh) and the OP Amp (X4). At this time, the first resistor (Rg) may be 100 kΩ or more, preferably 100 kΩ or more and 1000 kΩ or less, and more preferably 100 kΩ or more and 500 kΩ or less. According to an embodiment of the present invention, if the voltage distribution resistor of the A+ detection unit (620) includes a high first resistance of 100 kΩ or more, the flow of current through the A+ line is reduced when PE is opened, thereby minimizing the impact on the first voltage detection unit (600) and the second voltage detection unit (610).

[0080] Likewise, the A-detection unit (630) may include a voltage-dividing resistor unit and an OP Amp (X5). Here, the voltage-dividing resistor unit may be arranged between the fourth node (N4) of the A-line and the OP Amp (X5) to distribute the voltage entering the OP Amp (X5). For example, the voltage-dividing resistor unit may include a first resistor (Ri) and a second resistor (Rj), one end of the first resistor (Ri) may be connected to the fourth node (N4) of the A-line, and the other end of the first resistor (Ri) may be connected to one end of the second resistor (Rj) and the OP Amp (X5). At this time, the first resistor (Ri) may be 100 kΩ or more, preferably 100 kΩ or more and 1000 kΩ or less, and more preferably 100 kΩ or more and 500 kΩ or less. According to an embodiment of the present invention, if the voltage distribution resistor of the A- detection unit (630) includes a high first resistance of 100 kΩ or more, the flow of current through the A+ line is reduced when PE is opened, thereby minimizing the impact on the first voltage detection unit (600) and the second voltage detection unit (610).

[0081] In this way, according to an embodiment of the present invention, even when the EVCC (100) further includes an A+ detection unit (620) that detects the voltage of the A+ line through which a signal for enabling the EVCC (100) is transmitted, and an A- detection unit (630) that detects the voltage of the A- line through which a signal for enabling the EVCC (100) is transmitted, the influence of the A+ detection unit (620) and the A- detection unit (630) on the PE open detection of the first voltage detection unit (600) and the second voltage detection unit (610) can be minimized.

[0082] Table 1 shows the results of simulating the performance of the circuit diagrams of Figs. 6 to 9.

[0083] conditionssignalEVSE side PE&PG not connectedEVSE side PE&PG connectedA+ only connectedA+&A- only connectedA+&A- connectedValue entered into EV side MCU (V)Normal conditionA+01.072.982.98A-002.450CC14444CC20000PE openA+01.0700A-0000CC10000CC2-11.78-11.78-11.78-11.64

[0084] Referring to Table 1, when PE open occurs after entering charging mode and opening switch S3, the voltage of the CC1 line changes from 4 V to 0 V, and the voltage of the CC2 line changes from 0 V to approximately -12 V. Therefore, it can be seen that PE open can be detected using the voltage change amount of the CC1 line and the voltage change amount of the CC2 line.

[0085] In particular, referring to FIGS. 6 to 9 and Table 1, when a PE open occurs in a state where the A+ line and the A- line are not connected to the EVCC (100) side, that is, in a state where the EVCC (100) side does not use the A+ line and the A- line, it can be seen that a current flow from the EVSE (20) side power supply U1 to the PE line through the CC1 line is not formed, and therefore, PE open detection is possible based on the voltage change amount in the CC1 line and the voltage change amount in the CC2 line.

[0086] In addition, referring to FIGS. 6 to 9 and Table 1, even if the A+ line and the A- line are connected to the EVCC (100) side, but the ground PG on the auxiliary battery side of the EVSE (20) and the ground PE on the power source (U1) side are different from each other, it can be seen that since no current flow is formed from the power source U1 on the EVSE (20) side to the PE line via the CC1 line, it is possible to detect the PE open by the voltage change amount on the CC1 line and the voltage change amount on the CC2 line.

[0087] In addition, referring to FIGS. 6 to 9 and Table 1, when the A+ line and the A- line are connected to the EVCC (100) side, and the ground PG on the auxiliary battery side of the EVSE (20) and the ground PE on the power source (U1) side are connected to each other, a current flow can be formed from the power source U1 on the EVSE (20) side through the CC1 line, the A+ line, and the A- line. At this time, if the first resistance in the A+ detection unit (620) and the A- detection unit (630) is designed to be 100 kΩ or more as in the embodiment of the present invention, the current flow is controlled when the PE is open, and thus it can be seen that the influence of the A+ detection unit (620) and the A- detection unit (630) on the performance of the first voltage detection unit (600) and the second voltage detection unit (610) can be minimized, so that the voltage change amount in the CC1 line and the voltage change amount in the CC2 line can be precisely detected.

[0088] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

[0089] [Explanation of symbols]

[0090] 10: Electric cars

[0091] 20: Electric vehicle charging facilities

[0092] 22: Charging cable

[0093] 100: Electric Vehicle Charging Controller

[0094] 110: Control unit

[0095] 120: Connection

[0096] 130: Detection unit

Claims

1. In an electric vehicle charging controller (EVCC), CC1 (Connection Check 1) line, which transmits a signal for detecting connector connection between the EVSE (Electric Vehicle Supply Equipment) and the electric vehicle charging controller; A CC2 (Connection Check 2) line through which a signal is transmitted for detecting a connector connection between the EVSE and the electric vehicle charging controller; A first voltage detection unit connected to the CC1 line and detecting the voltage of the CC1 line; A second voltage detection unit connected to the CC2 line and detecting the voltage of the CC2 line, and A control unit is included that determines that the PE (protective earth) between the EVSE and the electric vehicle charging controller is open when the values ​​detected by the first voltage detection unit and the second voltage detection unit are within a predetermined value. An electric vehicle charging controller, wherein the second voltage detection unit includes a back-to-back FET (back to back field effect transistor), a positive voltage monitoring circuit, and a negative voltage monitoring circuit connected to the CC2 line.

2. In paragraph 1, The above negative voltage monitoring circuit is an electric vehicle charging controller including a voltage distribution resistor and an OP Amp (operational amplifier).

3. In paragraph 2, An electric vehicle charging controller in which the voltage distribution resistor includes a first resistor and a second resistor, one end of the first resistor is connected to the CC2 line, and the other end of the first resistor is connected to one end of the second resistor and the OP Amp.

4. In paragraph 3, An electric vehicle charging controller wherein the first resistance is 100 kΩ or greater.

5. In paragraph 1, The above positive voltage monitoring circuit is an electric vehicle charging controller including a voltage distribution resistor and an OP Amp.

6. In paragraph 1, A signal for detecting the connector connection on the EVSE side is transmitted through the CC1 line. An electric vehicle charging controller in which a signal for detecting a connector connection on the electric vehicle charging controller side is transmitted through the CC2 line.

7. In paragraph 6, An electric vehicle charging controller, wherein the first voltage detection unit includes a voltage distribution resistor unit and an OP Amp.

8. In paragraph 1, An electric vehicle charging controller in which the above control unit estimates the negative voltage of the voltage value detected by the negative voltage monitoring circuit using a pre-stored voltage matching table.

9. In paragraph 1, A+ line through which a signal for enabling the above electric vehicle charging controller is transmitted; A-line through which a signal for enabling the above electric vehicle charging controller is transmitted; An A+ detection unit that detects the voltage of the above A+ line, and An electric vehicle charging controller further comprising an A-detector for detecting the voltage of the A-line.

10. In paragraph 9, An electric vehicle charging controller, wherein the A+ detection unit and the A- detection unit each include a voltage distribution resistor and an OP Amp.

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