Communication control device for charging electric vehicle and error detection method thereof

Abstract

A communication control device for charging an electric vehicle according to an embodiment of the present invention comprises: a positive voltage detection unit for detecting a positive voltage of a control pilot (CP) signal in the form of pulse wide modulation (PWM) received from an electric vehicle supply equipment (EVSE); a negative voltage detection unit for detecting a negative voltage of the CP signal; and a control unit configured to detect an error at a first point by using a first value and detect an error at a second point by using a second value, wherein the first value is a voltage value detected by the negative voltage detection unit, and the first point is located on a protective earth (PE) line connecting a ground of the EVSE and a ground of the electric vehicle.

Description

Communication control device for charging electric vehicles and its error detection method

[0001] The present invention relates to an electric vehicle, and more particularly, to a communication control device for charging an electric vehicle and an error detection 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 EVSE and EV communicate through a connection between the two. Once connected, charging signaling occurs between the EVSE and EV, and charging begins.

[0004] The connection between the EVSE and the EV features a CP (control pilot) pin, through which a PWM (Pulse Wide Modulation) CP signal is transmitted from the EVSE to the EV. The interaction between the EVSE and the EV can be monitored and controlled through this CP signal, and the voltage and duty cycle of the CP signal can vary depending on the charging status.

[0005] 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.

[0006] If the Protective Earth (PE) line, the grounding wire between the EVSE and the EV, is disconnected, an emergency shutdown is required for safety reasons. Therefore, technology is needed to quickly and accurately detect breaks in the PE line.

[0007] The technical problem to be solved by the present invention is to provide a communication control device for charging an electric vehicle and an error detection method thereof.

[0008] According to one embodiment of the present invention, a communication control device for charging an electric vehicle includes a positive voltage detection unit for detecting a positive voltage of a CP (Control Pilot) signal in the form of PWM (Pulse Wide Modulation) received from an EVSE (Electric Vehicle Supply Equipment), a negative voltage detection unit for detecting a negative voltage of the CP signal, and a control unit configured to detect an error at a first point using a first value and an error at a second point using a second value, wherein the first value is a voltage value detected by the negative voltage detection unit, and the first point is located on a protective earth (PE) line connecting a ground of the EVSE and a ground of the electric vehicle.

[0009] At least one of the errors at the first point and the errors at the second point may be a short circuit of the protective ground line.

[0010] The control unit may determine that an error has occurred at the first point if the first value is outside a preset first range.

[0011] The above preset first range may be a voltage range between -13 V and -11 V.

[0012] The second value is a SLAC (Signal Level Attenuation Characterization) value, and the second point may be located on a line connecting the protective ground line and a PLC (Power Line Communication) modem.

[0013] If the above SLAC value is outside the preset second range, it can be determined that an error has occurred at the second point.

[0014] The control unit detects an error at a third point using a third value, the third value being a voltage value of a proximity detection (PD) line, and the third point may be located on a line connecting the protective ground line and the proximity detection line.

[0015] The second value may be a voltage value of a proximity detection (PD) line, and the second point may be located on a line connecting the protective ground line and the proximity detection line.

[0016] The first point and the second point may be positioned at an inlet for charging the electric vehicle.

[0017] The above negative voltage detection unit may include a voltage distribution resistor unit and an OP Amp (Operational Amplifier).

[0018] The above voltage distribution resistor may be placed between the CP line through which the CP signal is transmitted and the OP Amp.

[0019] The voltage distribution resistor unit includes a first resistor and a second resistor, one end of the first resistor is connected to the CP line, the other end of the first resistor is connected to one end of the second resistor and the OP Amp, the other end of the second resistor is connected to ground, and the resistance value of the first resistor may be greater than the resistance value of the second resistor.

[0020] One end of the first resistor may be connected to a node between the capacitor and diode of the CP line.

[0021] The control unit may be configured to shut down charging when it detects an error at the first point using the first value or when it detects an error at the second point using the second value.

[0022] A method for detecting an error in a communication control device for charging an electric vehicle according to one embodiment of the present invention includes the steps of receiving a CP (Control Pilot) signal in the form of PWM (Pulse Wide Modulation) from an EVSE (Electric Vehicle Supply Equipment), detecting a positive voltage and a negative voltage of the CP signal, and detecting an error at a first point using a first value and detecting an error at a second point using a second value, wherein the first value is a detected value of the negative voltage, and the first point is located on a protective earth (PE) line connecting a ground of the EVSE and a ground of the electric vehicle.

[0023] According to an embodiment of the present invention, a communication control device for charging an electric vehicle can be provided that quickly and accurately detects a break in the protective ground line between an EVSE and an EV. According to an embodiment of the present invention, an emergency shutdown can be performed in the event of a break in the protective ground line, thereby preventing safety accidents. According to an embodiment of the present invention, the precise location where a break in the protective ground line occurs can be detected, thereby enabling precise diagnosis and rapid recovery in the event of a fault.

[0024] FIGS. 1 and 2 are drawings showing a charging system for an electric vehicle according to one embodiment of the present invention.

[0025] Figure 3 is an example of an electrical equivalent circuit for charging between an EVSE and an EV.

[0026] Figure 4 shows a CP signal in PWM form output by EVSE.

[0027] Fig. 5 is a diagram showing a proximity detection circuit according to the combined charging system type 1 (CCS1).

[0028] Figure 6 is a circuit diagram of an integrated charging system type 2 (CCS2).

[0029] Figure 7 is a circuit diagram according to the GB / T AC standard.

[0030] Figure 8 is a block diagram of a communication control device according to an embodiment of the present invention.

[0031] Figure 9 is a flowchart of an error detection method of a communication control device according to an embodiment of the present invention.

[0032] FIG. 10 is an equivalent circuit diagram of a charging interface between an EVSE and an EV according to one embodiment of the present invention.

[0033] FIG. 11 is an equivalent circuit diagram of a charging interface between an EVSE and an EV according to another embodiment of the present invention.

[0034] FIG. 12 is an equivalent circuit diagram of a charging interface between an EVSE and an EV according to another embodiment of the present invention.

[0035] Fig. 13 is a circuit diagram of a negative voltage detection unit according to one embodiment of the present invention.

[0036] Fig. 14 is a circuit diagram of a positive voltage detection unit according to one embodiment of the present invention.

[0037] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] FIGS. 1 and 2 are drawings showing a charging system for an electric vehicle according to one embodiment of the present invention.

[0048] Referring to FIGS. 1 and 2, an electric vehicle (EV) 10 can be charged from an electric vehicle supply equipment (EVSE) 20. In this specification, an EV (10) refers to a vehicle propelled by an electric motor that draws current from a rechargeable storage battery or other portable energy storage device. Although this specification focuses on an EV (10), it is self-evident that the description can also be applied to a plug-in hybrid electric road vehicle (PHEV).

[0049] For this purpose, a charging cable (22) connected to the EVSE (20) can be connected to the inlet of the EV (10). Here, the EVSE (20) is a facility that supplies AC or DC, and can be placed at a charging station, placed in a 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.

[0050] An electric vehicle communication controller (EVCC, 100) for charging an electric vehicle is mounted in an EV (10) and connected to an electronic control unit (ECU) of the EV (10). For example, the communication control device (100) may be installed in the trunk of the EV (10), but is not limited thereto.

[0051] Here, the communication control device (100) can communicate with the EV (10) and EVSE (20), respectively.

[0052] The method of connecting the EV (10) to the EVSE (20) can be divided into four modes and three cases. Mode 1 is to connect the EV (10) to the AC supply network using a cable and a plug, which is connected to a standard socket outlet. Mode 2 is to connect the EV (10) to the AC supply network using a cable and a plug connected to a standard socket outlet, which has a protection system and CP function to prevent electric shock between the EV and the socket outlet. Mode 3 is to connect the EV (10) using an EVSE (20) permanently connected to the AC supply network, and the CP function is extended to control the devices within the EVSE (20). Mode 4 is to connect the EV (10) to the AC or DC supply network using a dc EVSE or a dc EV charging station using the CP function. Case A is to connect the EV (10) to the AC supply using a cable and plug assembly permanently attached to the EV. Case B connects the EV (10) to the supply using a detachable cable assembly at both ends. Case C connects the EV (10) to the supply using a supply cable and vehicle connector permanently attached to the EV charging station.

[0053] A cable assembly between an EV (10) and an EVSE (20) may include a CP conductor, which is an insulated conductor that creates a CP circuit, together with a PE conductor. Here, the CP circuit is a circuit designed for signal transmission or communication between the EV (10) and the EVSE (20), and the CP function may be used to monitor and control the interaction between the EV (10) and the EVSE (20). A CPF controller (control pilot function controller), which is a device that manages a CP signal and CP function, may be disposed in the EVSE (20). The proximity function may be an electrical or mechanical means that indicates a state in which a connector is inserted into an inlet of an EV (10) or a state in which a plug is inserted into a socket outlet at a charging station.

[0054] In Mode 2, Mode 3 and Mode 4, the EVSE (20) has the function of checking continuous continuity of the PE conductor, verifying that the EV (10) is properly connected to the EVSE (20), supplying power to the EV (10), stopping power supplied to the EV (10), and transmitting maximum current information. Here, in order to supply power to the EV (10), the CP function between the EVSE (20) and the EV (10) must be accurately set to a signal state that allows power supply.

[0055] In mode 2, mode 3 and mode 4, the CP function is performed through a CP circuit using PWM (pulse wide modulation).

[0056] Embodiments of the present invention can be applied not only to cases where the connector and charging cable are fixed to the EVSE (20) and connected to the EV (10), but also to cases where the connector and charging cable are fixed to the EV (10) and connected to the EVSE (20). In this specification, the connector and charging cable may mean a part of the EVSE (20) or a part of the EV (10). In this specification, the coupler may be used interchangeably with the connector, or may have the meaning of including the connector, or may have the meaning of being included in the connector.

[0057] Figure 3 is an example of an electrical equivalent circuit for charging between an EVSE and an EV.

[0058] Referring to Fig. 3, the EVSE (20) includes an oscillator that generates an AC voltage for charging, and the EV (10) includes resistors (R2, R3) and a switch (S2). Here, Va is the pilot wire voltage measured at the output terminal of the EVSE (20), Vg is the internal voltage of the oscillator, and Vb is the voltage, duty cycle, and frequency measured by the EV (10). The EVSE (20) communicates by setting the duty cycle of a PWM signal or a continuous DC voltage signal. The EVSE (20) can change the duty cycle of the PWM signal. The EV (10) responds by applying a resistive load to the positive half-wave of the CP circuit. If the EV (10) draws a current higher than the CP function (duty cycle), the EVSE (20) can open its switching device. At this time, the EVSE (20) will follow the conditions for the allowed response time of the EV (10), the current tolerance with respect to the duty cycle generated by the EVSE (20), and the tolerance of the current measurement in the EVSE (20) itself. The amount of voltage charged to the battery can be controlled by turning on and off the switch connected to the resistor on the EV (10) side.

[0059] The oscillator of EVSE (20) can generate and output a PWM signal of ±12 V, 1 kHz, and R1 can have a resistance value of 1 kΩ, but is not limited thereto. R3 of EV (10) has a resistance value of 2.74 kΩ, and R2 connected in series with S2 can have a resistance value of 1.3 kΩ or 270 Ω, but is not limited thereto.

[0060] Figure 4 shows a CP signal in PWM form output by EVSE.

[0061] Referring to Fig. 4, the EVSE (20) outputs a CP signal in the form of a PWM having a positive peak voltage of +12 V and a negative peak voltage of -12 V. The communication control device (100) of the EV (10) detects the duty cycle and voltage size of the CP signal to monitor and control the status.

[0062] The states according to the CP signal can be divided into state A, state B, state C, state D, state E, and state F. State A means a state in which the charger is not connected between the EVSE (20) and the EV (10), that is, an unplugged state, and when the positive peak of the CP signal is +12 V ± 1 V, it is determined to be state A. State B means a state in which the charger is connected between the EVSE (20) and the EV (10), that is, a plugged state, and may mean a state in which charging is ready. When the positive peak voltage of the CP signal is +9 V ± 1 V and the negative peak voltage is -12 V ± 1 V, it is determined to be state B. State C and state D mean a state in which charging is in progress, that is, a charging state, and in particular, state D may mean a state in which ventilation is required during charging. When the positive peak voltage of the CP signal is +6V±1V and the negative peak voltage is -12V±1V, it is determined to be in the C state, and when the positive peak voltage of the CP signal is +3V±1V and the negative peak voltage is -12V±1V, it is determined to be in the D state. The E state and the F state may indicate error states. For example, the E state may indicate a state in which power is not supplied to the EVSE (20), and the F state may indicate a state in which the EVSE (20) is unavailable. When the positive peak voltage of the CP signal is +0V±1V and the negative peak voltage is -12V±1V, it is determined to be in the E state, and when the CP signal is -12V±1V, it is determined to be in the F state.

[0063] Meanwhile, sleep mode is a mode for energy saving, and the EV (10) and EVSE (20) can enter sleep mode after negotiating a pause through the HLC protocol. On the EVSE (20) side, sleep mode means that the oscillator is turned off, the +12 V supply of the pilot line is maintained, and the power of the lower layer communication module is turned off. On the EV (10) side, sleep mode means the B state, and the power of the lower layer communication module can be turned off. The wake-up mechanism may also be used after the charging session has already ended so that the counterpart station can reset the HLC.

[0064] Table 1 describes the charging state by position of the CP signal shown in Fig. 4, and Table 2 shows the maximum current by duty ratio.

[0065] 위치StateCondition1AVehicle unconnected-the full generator voltage is measured by the EVSE at Va. The generator signal Vg is a +12V DC voltage2BThe cable assembly is connected to the vehicle and to the EVSE. This condition is detected by the 9V signal measured at Va. The voltage from the signal generator Vg may be either a steady state +12V DC or a ±12V, 1kHz signal, if the EVSE is immediately available for the supply of energy.3BThe EVSE is now able to supply energy and indicated the available current to the vehicle by the duty cycle. The presence of the diode D is detected by the -12V and gives added guarantee that the 9V signal is a reliable indication of a vehicle connected.4B→C,DS2 is closed by vehicle as a function of requirements to indicate that the vehicle can receive energy. There are no timing requirements for the closing of On.5C,DEVSE closes circuit. The timing of switch closure may be subject other requirements (payment, data exchange).If state D is detected, the switch will close only in ventilation requirements are met.6C,DCurrent drawn from the vehicle. The timing and current profile are determined by the vehicle. Current may not exceed that indicated by the duty cycle.7C,DExternal demand for power reduction. Such a demand may originate from the grid or by manual setting on EVSE. The vehicle adjusts the current demand to that indicated by the duty cycle.8C,DEnd of charge, decided by the vehicle.9C,D→BVehicle asks for disconnect. This may be the result of the proximity contact being opened.10BEVSE detects state B(created by opening of S on vehicle) and opens the contactor.11AComplete removal of cable assembly from vehicle or EVSE is detected by the 12V signal.Note: The EVSE should allow removal of the plug if the end of the charging session is ended by entering state A.

[0066] Nominal duty cycle interpretation by vehicleMaximum current to be drawn by vehicleDuty cycle <3%Charging not allowed3%≤duty cycle≤7%Indicates that digital communication will be used to control an off-board DC charger or communicate available line current for an on board charger. Digital communication may also be used with other duty cycles.Charging is not allowed without digital communication.5% duty cycle shall be used if the pilot function wire is used for digital communication7% <duty cycle<8%Charging not allowed8%≤duty cycle<10%6A10%≤duty cycle≤85%Available current=(% duty cycle)*0,6A85%<duty cycle≤96%Available current=(% duty cycle-64)*2,5A96%<duty cycle≤97%80ADuty cycle> 97%Charging not allowedIf the PWM signal is between 8% and 97%, the maximum current may not exceed the values ​​indicated by the PWM even if the digital signal indicates a higher current.

[0067] Interaction between EVSE (20) and EV (10) can be monitored and controlled through CP signal, and as described above, the voltage size of the CP signal can vary depending on the charging state.

[0068] Fig. 5 is a diagram showing a proximity detection circuit according to the combined charging system type 1 (CCS1).

[0069] As illustrated in Fig. 5, proximity detection can be performed through the connection of the connector of the EVSE (20) and the pin (31) of the inlet of the EV (10), and the ground (33) of the EVSE (20) and the ground (34) of the EV (10) can be connected through the pin (32). The resistances indicated in Fig. 5 are equivalent load resistances, and the resistance values ​​indicated for each resistor are nominal values.

[0070] Figure 6 is a circuit diagram of an integrated charging system type 2 (CCS2).

[0071] Referring to Fig. 6, the connector of the EVSE (20) and the inlet of the EV (10) can perform proximity detection through a pin (41) connection, and the ground (43) of the EVSE (20) and the ground (44) of the EV (10) can be connected through a pin (42). The resistor R6 can be referred to as a proximity resistor and can be defined as in Table 3.

[0072] Proximity Resistor(R6)Maximum current for ac chargingD.C.connector1500ΩNot applicableCombo2680Ω20ADC-type 2220Ω32ADC-type 2100Ω63ADC-type 2

[0073] Figure 7 is a circuit diagram according to the GB / T AC standard.

[0074] Referring to Fig. 7, the connector of the EVSE (20) and the inlet of the EV (10) can perform proximity detection through the connection of the pin (51), and the ground (53) of the EVSE (20) and the ground (54) of the EV (10) can be connected through the pin (52). In Fig. 7, the vehicle coupler connection status and RC resistance can be defined as in Table 4, and the mapping relationship between the maximum charging current generated by the EVSE (20) and the duty ratio can be defined as in Table 5.

[0075] StateRCR4S3Vehicle coupler connection state and rated currentState A--The vehicle coupler is not completely connected.State B-OpenThe mechanical locking device is unlocked.State C1.5kΩ / 0.5W a -ClosedThe vehicle coupler is completely connected, and the charging cable capacity is 10A.State C'1.5kΩ / 0.5W a 1.8kΩ / 0.5WOpenThe vehicle coupler is half connected.State D680Ω / 0.5W a -ClosedThe vehicle coupler has been completely connected, and the charging cable capacity is 16A.State D'680Ω / 0.5W a 2.7kΩ / 0.5WOpenThe vehicle coupler is half connected.State E220Ω / 0.5W a -ClosedThe vehicle coupler has been completely connected, and the charging cable capacity is 32A.State E'220Ω / 0.5W a3.3kΩ / 0.5WOpenThe vehicle coupler is half connected.State F100Ω / 0.5W a -ClosedThe vehicle coupler has been completely connected, and the charging cable capacity is 63A.State F'100Ω / 0.5W a 3.3kΩ / 0.5WOpenThe vehicle coupler is half connected. a Accuracy of resistor RC is ±3%.

[0076] PWM duty cycle DMaximum charging current I max (A)D=0%, continuous -12VCharging pile not availableD=5%5% duty cycle means digital communication is required, and the communication should be established between the charging pile and EV before energization.10%≤D≤85%I max =D*100*0.685% <D≤90%I max (D*100-64)*2.5, I max ≤6390% <D≤97%ReservedD=100%, continuous positive voltageNow allowed

[0077] Meanwhile, if the Protective Earth (PE) line, which is the grounding wire between the EVSE (20) and the EV (10), is disconnected, an emergency shutdown is required for safety reasons. Accordingly, a technology for quickly and accurately detecting a disconnection of the protective earth line is required. According to an embodiment of the present invention, an error detection device and method applicable to all CCS1, CCS2, and GB / T AC technologies are provided.

[0078] In this specification, the occurrence of a break in the protective ground line may include not only the case where a break occurs in the protective ground line that directly connects the ground of the EVSE (20) and the ground of the EV (10), but also all cases where a break occurs in the line connected to the protective ground line. For example, in the case where a break occurs in the line connecting the protective ground line and the PLC modem, and in the case where a break occurs in the line connecting the protective ground line and the proximity detection line, an emergency shutdown is required for safety reasons, just like in the case of a break in the protective ground line. In this specification, the break in the protective ground line may be used interchangeably with PE open or broken PE, and may be broadly interpreted to refer not only to the case where the protective ground line is disconnected, but also to all cases where an error or failure occurs in the protective ground line. Here, the protective ground line may also be referred to as the grounding wire of the high-voltage line between the EVSE (20) and the EV (10).

[0079] FIG. 8 is a block diagram of a communication control device according to an embodiment of the present invention, and FIG. 9 is a flowchart of an error detection method of a communication control device according to an embodiment of the present invention.

[0080] Referring to FIG. 8, the communication control device (100) includes a control unit (110), a connection unit (120), and a detection unit (130).

[0081] 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). The control unit (110) detects the duty ratio and voltage of the CP signal in PWM form received from the EVSE (20) to determine the charging status. The control unit (110) detects an error in the communication control device (100).

[0082] The connecting part (120) is connected to the EVSE (20) and transmits signals between the control part (110) and the EVSE (20). For example, the connecting part (120) may transmit a charging-related signal received from the EVSE (20) to the control part (110) and transmit a control signal for charging generated by the control part (110) to the EVSE (20). In addition, the connecting part (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 part (110). At least a part of the connecting part (120) may be placed in the inlet of the EV (10) or connected to the inlet of the EV (10). The inlet of the EV (10) may be used interchangeably with the charging port to which the connector is connected.

[0083] According to an embodiment of the present invention, the connection unit (120) may include a PE (protective earth) pin. The PE pin is a ground pin and may be a reference for a control line. The PE pin may be included in a grounding wire between the EVSE (20) and the EV (10). The connection unit (120) may further include a CP (control pilot) pin. The CP pin is a pin that transmits and receives a CP signal in the form of PWM. The connection unit (120) may further include a PD (proximity detection) pin that detects a connector connection. The connection unit (120) may further include a DC- pin and a DC+ pin that receive power from the EVSE (20). The connection unit (120) may further include an A+ pin and an A- pin that are connected to an auxiliary battery to enable the communication control device (100).

[0084] 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 a signal received through the connection unit (120) to the control unit (110). The detection unit (130) detects the duty ratio and voltage of the CP signal. To this end, the detection unit (130) includes a positive voltage detection unit that detects a positive voltage of the CP signal and a negative voltage detection unit that detects a negative voltage of the CP signal. The detection unit (130) may further include a proximity detection unit that detects proximity of the connector.

[0085] Referring to FIGS. 8 and 9, a communication control device (100) according to an embodiment of the present invention receives a CP signal in the form of PWM from an EVSE (20) (S900), detects positive and negative voltages of the CP signal (S910), detects an error at a first point using a first value, and detects an error at a second point using a second value (S920). Since the embodiment of the present invention relates to a technology for detecting an error of the communication control device (100), and more specifically, detecting a disconnection of a protective ground line, the description will focus on detecting a disconnection of the protective ground line of the communication control device (100). It is obvious that known technologies can be applied to other features of the communication control device (100) except for detecting a disconnection of the protective ground line.

[0086] More specifically, in step S920, the control unit (110) of the communication control device (100) can not only detect whether a protective ground line is disconnected using the value detected by the detection unit (130), but also detect the specific point where a disconnection of the protective ground line occurred.

[0087] Here, the first value is a voltage value detected by the negative voltage detection unit of the CP signal, and the first point is located on a protective ground line connecting the ground of the EVSE (20) and the ground of the EV (10). If the voltage value detected by the negative voltage detection unit of the CP signal is outside a preset first range, it can be determined that an error has occurred at the first point. Here, the preset first range can be a voltage range between -13 V and -11 V, and if the voltage value detected by the negative voltage detection unit of the CP signal is less than -13 V or greater than -11 V, it can be determined that an error has occurred at the first point.

[0088] Meanwhile, the second value is a SLAC (Signal Level Attenuation Characterization) value, and the second point may be located on a line connecting a protective ground line and a power line communication (PLC) modem. The SLAC value is an index indicating the degree of signal attenuation between a transmission signal and a reception signal in a power line communication environment between the EVSE (20) and the EV (10). If the SLAC value is out of a preset second range, the control unit (110) may determine that a break has occurred at the second point, which is a line connecting the protective ground line and the power line communication modem. Here, the preset second range may be 21 dB or more, preferably 30 dB or more, and more preferably 40 dB or more. For example, if the SLAC value is 40 dB or more, the control unit (110) may determine that a break has occurred on the line connecting the protective ground line and the power line communication modem, and may perform an emergency shutdown.

[0089] Alternatively, the second value may be a voltage value of a proximity detection (PD) line, and the second point may be located on a line connecting a protective ground line and a proximity detection line. That is, when the voltage value of the proximity detection line is outside the preset second value, the control unit (110) may determine that a break has occurred in the line connecting the protective ground line and the proximity detection line. Here, the preset second range may be 4.9 V or less. For example, when the voltage value of the proximity detection line exceeds 4.9 V, the control unit (110) may determine that a break has occurred in the line connecting the protective ground line and the proximity detection line.

[0090] According to an embodiment of the present invention, the first point and the second point may be points located in the inlet for charging the EV (10). According to an embodiment of the present invention, when a short circuit occurs in the inlet of the EV (10), it is possible to quickly and accurately detect whether there is a short circuit and the location of the short circuit without having to disassemble the inlet.

[0091] Hereinafter, embodiments of the present invention will be described in more detail using specific circuit diagrams and simulation results.

[0092] Fig. 10 is an equivalent circuit diagram of a charging interface between an EVSE and an EV according to one embodiment of the present invention, Fig. 11 is an equivalent circuit diagram of a charging interface between an EVSE and an EV according to another embodiment of the present invention, and Fig. 12 is an equivalent circuit diagram of a charging interface between an EVSE and an EV according to still another embodiment of the present invention. Since the embodiment of the present invention relates to detection of a disconnection of a protective ground line of a communication control device (100), a simplified circuit diagram is illustrated and described focusing on the configuration related to detection of a disconnection of a protective ground line, and it is obvious that known technologies can be applied to the remaining configurations except for the configuration related to detection of a disconnection of a protective ground line.

[0093] Referring to Fig. 10, in order to charge the EV (10), the coupler (21) of the EVSE (20) and the inlet (11) within the EV (10) are coupled. The inlet (11) can be connected to a communication control device (100). As illustrated, the EVSE (20) and the communication control device (100) within the EV (10) are connected via a CP line, a PD line, and a PE line. An oscillator (22) disposed in the EVSE (20) generates a ±12V PWM waveform of a predetermined frequency (e.g., 1 kHz) and transmits it to the communication control device (100) within the EV (10) via the CP line. The detection unit (130) of the communication control device (100) includes a positive voltage detection unit (131) and a negative voltage detection unit (132). The positive voltage detection unit (131) detects a positive voltage of a CP signal in the form of a PWM, and the negative voltage detection unit (132) detects a negative voltage of the CP signal. Although not shown, the detection unit (130) of the communication control device (100) further includes a duty ratio detection unit that detects a duty ratio of the CP signal, and the control unit (110) of the communication control device (100) determines a charging state based on the positive voltage, negative voltage, and duty ratio of the CP signal. The detection unit (130) of the communication control device (100) further includes a proximity detection unit (133), and can detect the connection of the connector (21) of the EVSE (20) by using the voltage value of a proximity detection signal transmitted along the PD line when the connector of the EVSE (20) is connected. The communication control device (100) according to an embodiment of the present invention further includes a PLC modem (140). Accordingly, the communication control device (100) of the EVSE (20) and the EV (10) performs power line communication.

[0094] According to an embodiment of the present invention, a protective ground fault may be caused by a disconnection of a protective ground line or a disconnection of a line connected to the protective ground line, which may be referred to as a PE open or a broken PE. In the present specification, a disconnection that occurs directly on the protective ground line connecting the ground of the EVSE (20) and the ground of the EV (10) may be referred to as a PE open that occurs at a first point. The PE open that occurs at a first point may be divided into a PE open that occurs in area A, which is the front end of the inlet (11) connected to the coupler (21), and a PE open that occurs in area B, which is between the node where the line connecting the protective ground line and the proximity detection line meets the protective ground line and the ground within the EV (10). A PE open that occurs in the line between the protective ground line and the PLC modem (140) or a PE open that occurs on the line between the protective ground line and the proximity detection line may be referred to as a PE open that occurs at a second point or a PE open that occurs at a third point. A PE open that occurs on the line between the protective ground line and the PLC modem (140) may be displayed in area C, and a PE open that occurs on the line between the protective ground line and the proximity detection line may be displayed in area D.

[0095] According to an embodiment of the present invention, a PE open occurring at the first point is detected based on a value detected by a negative voltage detection unit (132). In addition, a PE open occurring on a line between a protective ground line and a PLC modem (140) can be detected based on a SLAC value, and a PE open occurring on a line between a protective ground line and a proximity detection line can be detected based on a value detected by a proximity detection unit (133).

[0096] Below, the results of simulating PE open detection using the circuit diagram of Fig. 10 are described. The EVSE (20) outputs a PWM waveform of ±12 V, the charging state is divided into B2 and C2, and the simulation was conducted in a state where the switch S in the coupler (21) is closed and the proximity resistance is 150Ω.

[0097] Charge status UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)Positive voltage detectionV8.978.978.97Negative voltage detectionV-12-11.93-11.93C2(PWM 6V / -12V)Positive voltage detectionV6.016.016.01Negative voltage detectionV-11.94-11.94-11.94

[0098] Charge Status Open Position UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)A Positive voltage detection V11.7611.5611.51 Negative voltage detection V-7.54-7.6-7.85 B Positive voltage detection V12.1511.711.65 Negative voltage detection V-7.02-7.36-7.7C Positive voltage detection V8.988.988.98 Negative voltage detection V-12-11.95-11.95D Positive voltage detection V8.978.978.98 Negative voltage detection V-11.94-12-11.93C2(PWM 6V / -12V)A Positive voltage detection V7.57.257.15 Negative voltage detection V-7.55-7.7-8.3B Positive voltage Detection V7.747.367.28 Negative voltage detection V-7.05-7.5-8.15C Positive voltage detection V6.016.016.01 Negative voltage detection V-11.95-11.95-11.95D Positive voltage detection V6.016.016.01 Negative voltage detection V-11.94-11.94-11.94

[0099] Referring to Table 6, in a normal state where no PE open occurs and the charging state is B2, the positive voltage is detected between 8 V and 10 V and the negative voltage is detected between -13 V and -11 V. When the charging state is C2, the positive voltage is detected between 5 V and 7 V and the negative voltage is detected between -13 V and -11 V. However, referring to Table 7, when a PE open occurs in region A or region B, when the charging state is B2, the positive voltage is detected in a range outside 8 to 10 V and the negative voltage is detected in a range outside -13 V and -11 V. When the charging state is C2, the positive voltage is detected in a range outside 5 to 7 V and the negative voltage is detected in a range outside -13 V and -11 V. In particular, in both cases where the charge state is B2 and C2, the negative voltage significantly deviates from the preset range compared to the positive voltage, so it is easy to detect the PE open in the A region or B region using the negative voltage of the CP signal.

[0100] However, when a PE open occurs in the C or D region, it can be seen that both the positive and negative voltages are measured within the normal range when the charge state is B2 and C2. Therefore, when a PE open occurs in the C or D region, another method is required to detect it.

[0101] According to an embodiment of the present invention, it can be seen from the SLAC value that a PE open has occurred in the C region. Table 8 shows the results of simulating the SLAC value in a normal state and when a PE open has occurred in the C region.

[0102] Sample No.#1#2#3#4#5 Status Normal PE open Normal PE open Normal PE open Normal PE open Normal PE open SLAC value (dB) 642740642641742

[0103] Referring to Table 8, it can be seen that the SLAC value is 10 dB or less when the coupler (21) of the EVSE (20) is connected to the inlet (11) of the EV (10) and no PE open occurs, but the SLAC value is 21 dB or more when a PE open occurs in the C region. From this, it can be inferred that a PE open occurs in the C region when the detection values ​​of the positive voltage detection unit (131) and the negative voltage detection unit (132) are normal but the SLAC value is outside the preset range.

[0104] Meanwhile, according to an embodiment of the present invention, it can be known from the detection value of the proximity detection unit (133) that a PE open has occurred in the D region. Table 9 shows the simulation results of the detection value of the proximity detection unit (133) in a normal state and when a PE open has occurred in the D region.

[0105] Charge Status Status UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)PE openV4.984.984.98NormalV4.454.454.45C2(PWM 6V / -12V)PE openV4.984.984.98NormalV4.454.454.5

[0106] Referring to Table 9, it can be seen that the detection value of the proximity detection unit (133) is 4.5 V or less when the coupler (21) of the EVSE (20) is connected to the inlet (11) of the EV (10) and no PE open occurs, but the detection value of the proximity detection unit (134) exceeds 4.5 V when a PE open occurs in the D region. From this, it can be inferred that a PE open occurs in the D region when the detection values ​​of the positive voltage detection unit (131) and the negative voltage detection unit (132) are normal, but the detection value of the proximity detection unit (133) is outside the preset range.

[0107] Referring to Fig. 11, in order to charge the EV (10), the coupler (21) of the EVSE (20) and the inlet (11) of the communication control device (100) within the EV (10) are coupled. As illustrated, the EVSE (20) and the communication control device (100) within the EV (10) are connected via a CP line, a PD line, and a PE line. An oscillator (22) disposed in the EVSE (20) generates a ±12 V PWM waveform of a predetermined frequency (e.g., 1 kHz) and transmits it to the communication control device (100) within the EV (10) via the CP line. The detection unit (130) of the communication control device (100) includes a positive voltage detection unit (131) and a negative voltage detection unit (132). The positive voltage detection unit (131) detects a positive voltage of a CP signal in the form of a PWM, and the negative voltage detection unit (132) detects a negative voltage of the CP signal. Although not shown, the detection unit (130) of the communication control device (100) further includes a duty ratio detection unit that detects the duty ratio of the CP signal, and the control unit (110) of the communication control device (100) determines the charging state based on the positive voltage, negative voltage, and duty ratio of the CP signal. The detection unit (130) of the communication control device (100) further includes a proximity detection unit (133), and can detect the connection of the coupler (21) of the EVSE (20) using the voltage value of the proximity detection signal transmitted along the PD line when the connector (21) of the EVSE (20) is connected. The communication control device (100) according to an embodiment of the present invention further includes a PLC modem (140). Accordingly, the communication control device (100) of the EVSE (20) and the EV (10) perform power line communication.

[0108] According to an embodiment of the present invention, a protective ground fault may be caused by a disconnection of a protective ground line or a disconnection of a line connected to the protective ground line, which may be referred to as a PE open. In this specification, a PE open that occurs on a protective ground line connecting the ground of the EVSE (20) and the ground of the EV (10) may be referred to as a PE open that occurs at a first point. The PE open that occurs at the first point may be divided into a PE open that occurs in area A, which is the front end of the inlet (11) connected to the coupler (21) of the EVSE (20), and a PE open that occurs in area B, which is between the protective ground line and the ground within the EV (10). A PE open that occurs on the line between the protective ground line and the PLC modem (140) may be referred to as a PE open that occurs at a second point. A PE open that occurs on the line between the protective ground line and the PLC modem (140) may be indicated in area C. Unlike the embodiment of Fig. 10, the proximity resistor connected to the proximity detection unit (133) is placed in the coupler (21) of the EVSE (20) rather than the inlet (11) of the EV (10), so the PE open that occurs on the line connecting the protective ground line and the proximity detection line is not considered in this embodiment.

[0109] According to an embodiment of the present invention, a PE open occurring at the first point is detected based on a value detected by a negative voltage detection unit (132). In addition, a PE open occurring on a line between a protective ground line and a PLC modem (140) is detected based on a SLAC value.

[0110] Hereinafter, the results of simulating PE open detection using the circuit diagram of Fig. 11 are described. The proximity resistance R connected to the proximity detection unit (133) can have one of the values ​​of 1.5 kΩ, 680 Ω, 220 Ω, and 100 Ω, but in the present simulation result, the proximity resistance R is 100 Ω.

[0111] Charge status UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)Positive voltage detectionV8.978.988.98Negative voltage detectionV-11.94-11.94-11.94C2(PWM 6V / -12V)Positive voltage detectionV6.016.016.01Negative voltage detectionV-11.94-11.94-11.94

[0112] Charge Status Open Position UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)A Positive voltage detection V12.211.7511.65 Negative voltage detection V-7.1-7.7-7.86 B Positive voltage detection V12.211.811.6 Negative voltage detection V-7.1-7.6-7.9 C Positive voltage detection V8.988.988.98 Negative voltage detection V-11.95-11.95-11.95 C2(PWM 6V / -12V)A Positive voltage detection V7.857.457.25 Negative voltage detection V-7.16-7.8-8.6 B Positive voltage detection V7.877.457.2 Negative voltage detection V-7.18-7.7-8.58 C Positive voltage Detection V6.016.016.01 Negative voltage detection V-11.95-11.95-11.95

[0113] Referring to Table 10, in a normal state where no PE open occurs and the charging state is B2, the positive voltage is detected between 8 V and 10 V and the negative voltage is detected between -13 V and -11 V, and when the charging state is C2, the positive voltage is detected between 5 V and 7 V and the negative voltage is detected between -13 V and -11 V. However, referring to Table 11, when a PE open occurs in region A or region B, when the charging state is B2, the positive voltage is detected in a range outside 8 to 10 V and the negative voltage is detected in a range outside -13 V and -11 V, and when the charging state is C2, the positive voltage is detected in a range outside 5 to 7 V and the negative voltage is detected in a range outside -13 V and -11 V. In particular, in both cases where the charge state is B2 and C2, the negative voltage significantly deviates from the preset range compared to the positive voltage, so it is easy to detect the PE open in the A region or B region using the negative voltage of the CP signal.

[0114] However, when a PE open occurs in the C region, it can be seen that both the positive and negative voltages are measured within the normal range when the charging state is B2 and C2. Therefore, when a PE open occurs in the C region, another method for detecting it is necessary. As described above, when the detection values ​​of the positive voltage detection unit (131) and the negative voltage detection unit (132) are normal, but the SLAC value is outside the preset range, it can be assumed that a PE open has occurred in the C region.

[0115] Referring to Fig. 12, in order to charge the EV (10), the coupler (21) of the EVSE (20) and the inlet (11) of the communication control device (100) within the EV (10) are coupled. As illustrated, the EVSE (20) and the communication control device (100) within the EV (10) are connected via a CP line, a PD line, and a PE line. An oscillator (22) disposed in the EVSE (20) generates a ±12 V PWM waveform of a predetermined frequency (e.g., 1 kHz) and transmits it to the communication control device (100) within the EV (10) via the CP line. The detection unit (130) of the communication control device (100) includes a positive voltage detection unit (131) and a negative voltage detection unit (132). The positive voltage detection unit (131) detects a positive voltage of a CP signal in the form of a PWM, and the negative voltage detection unit (132) detects a negative voltage of the CP signal. Although not shown, the detection unit (130) of the communication control device (100) further includes a duty ratio detection unit that detects the duty ratio of the CP signal, and the control unit (110) of the communication control device (100) determines the charging state based on the positive voltage, negative voltage, and duty ratio of the CP signal. The detection unit (130) of the communication control device (100) further includes a proximity detection unit (133), and can detect the connection of the coupler (21) of the EVSE (20) by using the voltage value of the proximity detection signal transmitted along the PD line when the coupler (21) of the EVSE (20) is connected.

[0116] According to an embodiment of the present invention, a protective ground fault may be caused by a disconnection of a protective ground line or a disconnection of a line connected to the protective ground line, which may be referred to as a PE open. In this specification, a PE open that occurs directly on a protective ground line connecting the ground of the EVSE (20) and the ground of the EV (10) may be referred to as a PE open that occurs at a first point. The PE open that occurs at the first point may be divided into a PE open that occurs in area A, which is the front end of the inlet (11) connected to the coupler (21) of the EVSE (20), and a PE open that occurs in area B, which is between the protective ground line and the ground within the EV (10). A PE open that occurs on the line between the protective ground line and the proximity detection line may be referred to as a PE open that occurs at a second point. A PE open that occurs on the line between the protective ground line and the proximity detection line may be indicated in area D.

[0117] According to an embodiment of the present invention, a PE open occurring at the first point is detected based on a value detected by a negative voltage detection unit (132). A PE open occurring on a line between a protective ground line and a proximity detection line can be detected based on a value detected by a proximity detection unit (133).

[0118] Below, the results of simulating PE open detection using the circuit diagram of Fig. 12 are described.

[0119] Charge status UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)Positive voltage detection V8.988.988.98Negative voltage detection V-11.94-11.94-11.94

[0120] Charge Status Open Position UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)A Positive Voltage Detection V11.76 11.56 11.51 Negative Voltage Detection V-7.5 4-7.6-7.85 B Positive Voltage Detection V12.15 11.7 11.65 Negative Voltage Detection V-7.02-7.36-7.7 D Positive Voltage Detection V8.9 78.97 8.98 Negative Voltage Detection V-11.94-12-11.93

[0121] Referring to Table 12, in a normal state where no PE open occurs and the charging state is B2, the positive voltage is detected between 8 V and 10 V and the negative voltage is detected between -13 V and -11 V. However, referring to Table 13, when a PE open occurs in region A or region B, it can be seen that when the charging state is B2, the positive voltage is detected in a range outside 8 to 10 V and the negative voltage is detected in a range outside -13 V to -11 V. In particular, when the charging state is B2, the negative voltage deviates significantly from the preset range compared to the positive voltage, so it is easy to detect the PE open in region A or region B using the negative voltage of the CP signal.

[0122] However, when a PE open occurs in the D region, it can be seen that the positive and negative voltages are measured within the normal range. Therefore, when a PE open occurs in the D region, another method for detecting it is required. According to an embodiment of the present invention, it can be known that a PE open occurs in the D region from the detection value of the proximity detection unit (133). Table 14 shows the simulation results of the detection values ​​of the proximity detection unit (133) in the normal state and when a PE open occurs in the D region.

[0123] Charge status Status UnitDuty 5%Duty 50%Duty 95%B2(PWM 9V / -12V)PE openV4.964.964.96 NormalV3.893.893.89

[0124] Referring to Table 14, it can be seen that the detection value of the proximity detection unit (133) is 4.5 V or less when the connector (21) of the EVSE (20) is connected to the inlet (11) of the EV (10) and no PE open occurs, but the detection value of the proximity detection unit (133) exceeds 4.5 V when a PE open occurs in the D region. From this, it can be inferred that a PE open occurs in the D region when the detection values ​​of the positive voltage detection unit (131) and the negative voltage detection unit (132) are normal, but the detection value of the proximity detection unit (133) is outside the preset range.

[0125] Fig. 13 is a circuit diagram of a negative voltage detection unit according to one embodiment of the present invention, and Fig. 14 is a circuit diagram of a positive voltage detection unit according to one embodiment of the present invention.

[0126] Referring to Fig. 13, a negative voltage detection unit (132) is connected to a first node (N1) of a CP line. The first node (N1) of the CP line may be between a capacitor and a diode. The negative voltage detection unit (132) may include a voltage-dividing resistor unit and an OP Amp (X1). Here, the voltage-dividing resistor unit may be arranged between the first node (N1) of the CP 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 CP 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 resistor (Ra) may be at least twice the second resistor (Rb). For example, the resistance value of the first resistor (Ra) may be 220 kΩ, and the resistance value of the second resistor (Rb) may be 100 kΩ. In this way, when the first resistor (Ra) of the voltage distribution resistor unit is designed to be 100 kΩ or more, a structure capable of accurately detecting a voltage value can be obtained without causing an electrical influence on the peripheral circuit by reducing the current flow through the CP line when PE is open, and without placing a load on the MCU, which is the control unit (110).

[0127] According to an embodiment of the present invention, the negative voltage detection unit (132) may further include a diode (D3) disposed between the voltage-dividing resistor unit and the OP Amp (X1). The cathode of the diode (D3) may be connected to the voltage-dividing resistor unit, 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 unit is blocked, and the negative voltage of the CP line can be easily monitored.

[0128] Meanwhile, the negative voltage detection unit (132) is connected to the control unit (110), and when the voltage value detected by the negative voltage detection unit (132) is within a predetermined value, the control unit (110) determines that the PE (protective earth) between the EVSE (20) and the EV (10) is open.

[0129] Meanwhile, according to an embodiment of the present invention, the positive voltage detection unit (131) may also include a voltage-dividing resistor unit and an OP Amp (X2). Here, the voltage-dividing resistor unit may be connected to Vb of the CP line 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 Vb of the CP 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 detection unit (131) includes a voltage distribution resistor, the control unit (110) 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 detection unit (131) includes a high first resistor (Rc) of 100 kΩ or more, the current flow when PE is opened can be reduced, thereby minimizing the electrical influence of the positive voltage detection unit (131) on the CP line.

[0130] In this way, according to an embodiment of the present invention, a PE open detection method applicable to CCS1, CCS2, and GB / T AC standards can be obtained. In particular, according to an embodiment of the present invention, when a short circuit occurs in a protective ground line or a line connected to a protective ground line, it is possible to accurately and quickly extract not only whether a short circuit has occurred but also the location of the short circuit.

[0131] 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.

[0132] [Explanation of symbols]

[0133] 10: Electric cars

[0134] 20: Electric vehicle charging facilities

[0135] 22: Charging cable

[0136] 100: Communication control device

[0137] 110: Control unit

[0138] 120: Connection

[0139] 130: Detection unit

[0140] 140: PLC modem

Claims

1. In a communication control device for charging an electric vehicle, A positive voltage detection unit that detects the positive voltage of a CP (Control Pilot) signal in the form of PWM (Pulse Wide Modulation) received from EVSE (Electric Vehicle Supply Equipment). A negative voltage detection unit that detects the negative voltage of the CP signal, and A control unit is configured to detect an error at a first point using a first value and to detect an error at a second point using a second value, A communication control device in which the first value is a voltage value detected by the negative voltage detection unit, and the first point is located on a protective earth (PE) line connecting the ground of the EVSE and the ground of the electric vehicle.

2. In paragraph 1, A communication control device wherein at least one of the errors at the first point and the errors at the second point is a disconnection of the protective ground line.

3. In paragraph 1, A communication control device that determines that an error has occurred at the first point when the first value is outside a preset first range.

4. In paragraph 3, A communication control device wherein the above preset first range is a voltage range between -13 V and -11 V.

5. In paragraph 1, The second value is a SLAC (Signal Level Attenuation Characterization) value, and the second point is a communication control device located on a line connecting the protective ground line and a PLC (Power Line Communication) modem.

6. In paragraph 5, A communication control device that determines that an error has occurred at the second point when the above SLAC value is outside the preset second range.

7. In paragraph 5, A communication control device in which the control unit detects an error at a third point using a third value, the third value being a voltage value of a proximity detection (PD) line, and the third point is located on a line connecting the protective ground line and the proximity detection line.

8. In paragraph 1, A communication control device wherein the second value is a voltage value of a proximity detection (PD) line, and the second point is located on a line connecting the protective ground line and the proximity detection line.

9. In paragraph 1, The first point and the second point are communication control devices placed at an inlet for charging the electric vehicle.

10. In a method for detecting errors in a communication control device for charging an electric vehicle, A step of receiving a CP (Control Pilot) signal in the form of PWM (Pulse Wide Modulation) from EVSE (Electric Vehicle Supply Equipment). A step of detecting the positive and negative voltages of the CP signal, and A step of detecting an error at a first point using a first value and detecting an error at a second point using a second value, An error detection method wherein the first value is a detection value of the negative voltage, and the first point is located on a protective earth (PE) line connecting the ground of the EVSE and the ground of the electric vehicle.

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