KR20240052738A - Apparatus for detecting ground error and method thereof - Google Patents

Abstract

A ground fault detection device according to an embodiment of the present invention includes a switch unit disposed between an electric vehicle charging equipment (EVSE) and an electric vehicle, a switch control unit that controls the switch unit, a connector of the electric vehicle charging device, and the electric vehicle. A proximity detection unit that detects the proximity of the inlet of the car, a control signal analysis unit that detects the PWM duty ratio of the charging control signal and the voltage magnitude of the charging control signal, and the PWM duty ratio of the charging control signal. and an error detection unit that detects an open position of a protective earth (PE) line of the electric vehicle based on at least one of the ratio, the voltage magnitude of the charging control signal, and the proximity determination result.

Description

Ground fault detection device and method {APPARATUS FOR DETECTING GROUND ERROR AND METHOD THEREOF}

The embodiment relates to a ground fault detection device and method for detecting a ground fault occurring in a PE line of an electric vehicle charging device.

Eco-friendly vehicles such as electric vehicles (EV) or plug-in hybrid electric vehicles (PHEV) use electric vehicle supply equipment (EVSE) installed at charging stations to charge their batteries. .

To this end, an electric vehicle charging controller (EVCC) is mounted in the EV, communicates with the EV and EVSE, and controls charging of the electric vehicle.

For example, when the EVCC receives a signal from the electric vehicle indicating the start of charging, it can be controlled to start charging, and when it receives a signal from the electric vehicle indicating the end of charging, it can be controlled to end charging.

Charging methods for electric vehicles can be divided into fast charging and slow charging depending on the charging time. In the case of fast charging, the battery is charged by direct current supplied from the charger, and in the case of slow charging, the battery is charged by alternating current supplied to the charger. Therefore, the charger used for fast charging is called a fast charger or DC charger, and the charger used for slow charging is called a slow charger or AC charger.

Meanwhile, since electric vehicles are charged with high voltage and high current, requirements for safety during charging are increasing. To this end, the electric vehicle charging equipment (EVSE) and the electric vehicle (EV) connect the PE ground line to prevent safety accidents that may occur during charging. If a situation occurs where the PE ground becomes open, charging must be stopped immediately. Otherwise, the user may receive an electric shock. To this end, it is necessary to detect a ground fault in the PE ground line and detect the location where the ground fault occurs for quick response, but there is a problem that there is currently no technology for detecting the fault in the PE ground line and the location of the fault.

The technical problem to be achieved by the present invention is to provide a ground fault detection device and method for detecting a protective ground open fault occurring in the PE line of an electric vehicle charging device.

A ground fault detection device according to an embodiment of the present invention includes a switch unit disposed between an electric vehicle charging equipment (EVSE) and an electric vehicle, a switch control unit that controls the switch unit, a connector of the electric vehicle charging device, and the electric vehicle. A proximity detection unit that detects the proximity of the inlet of the vehicle, a control signal analysis unit that detects the PWM duty ratio of the charging control signal and the voltage magnitude of the charging control signal, and the PWM duty ratio of the charging control signal. and an error detection unit that detects an open position of a protective earth (PE) line of the electric vehicle based on at least one of the ratio, the voltage magnitude of the charging control signal, and the proximity determination result.

The switch unit may have a first end connected to a protective earth (PE) terminal of the electric vehicle charging device, and a second end connected to the proximity detection unit.

The switch control unit may control the switch unit to repeat opening and shorting according to a preset cycle.

The proximity detection unit may detect that the connector and the inlet are close when the magnitude of the voltage applied to the resistance included in the electrical closed loop formed by the electric vehicle charging device and the electric vehicle is greater than a preset voltage magnitude. .

The error detection unit is configured to connect the chassis ground terminal of the electric vehicle and the It may be determined that the first protective ground line connecting the protective ground terminal of the electric vehicle charging device is in a normal state.

The error detection unit is configured to contact the chassis ground terminal of the electric vehicle and the It may be determined that the first protective ground line connecting the protective ground terminal of the electric vehicle charging device is open.

If the error detection unit determines that the connector and the inlet are close while the switch unit is short-circuited, the second protective ground line connecting the proximity detection unit of the electric vehicle and the protective ground terminal of the electric vehicle charging device is normal. It can be judged to be in a state.

If the error detection unit determines that the connector and the inlet are not close while the switch unit is short-circuited, a second protective ground line connecting the proximity detection unit of the electric vehicle and the protective ground terminal of the electric vehicle charging device It can be determined that this is in an open state.

Opening and short-circuiting a switch disposed between an electric vehicle charging device (EVSE) and an electric vehicle according to a preset cycle, determining whether the connector of the electric vehicle charging device is close to the inlet of the electric vehicle. Detecting, detecting the PWM duty ratio of the charging control signal and the voltage magnitude of the charging control signal, and determining the PWM duty ratio of the charging control signal, the voltage magnitude of the charging control signal, and whether the proximity is and detecting an open position of a protective earth (PE) line of the electric vehicle based on at least one of the determination results.

The step of detecting the open position of the protective ground line of the electric vehicle includes, when the PWM duty ratio is not included in a preset first range and the voltage magnitude is not included in a preset second range while the switch is open, the electric vehicle It may be determined that the first protective ground line connecting the chassis ground terminal of the vehicle and the protective ground terminal of the electric vehicle charging device is in an open state.

The step of detecting the open position of the protective ground line of the electric vehicle includes protecting the proximity detection unit of the electric vehicle and the electric vehicle charging device when it is determined that the connector and the inlet are not close to each other while the switch is short-circuited. It may be determined that the second protective ground line connecting the ground terminal is open.

1 is a diagram for explaining an electric vehicle charging system according to an embodiment of the present invention.
Figure 2 is a diagram showing a proximity detection circuit according to Combined Charging System type 1 (CCS1).
Figure 3 is a diagram showing integrated charging system type 2 (CCS2).
Figure 4 is a diagram showing a CP (control pilot) circuit according to the DIN (Deutsches Institute further Normung) standard.
Figure 5 is a configuration diagram of a ground fault detection device according to an embodiment of the present invention.
Figure 6 is a diagram for explaining the arrangement of the switch unit according to an embodiment of the present invention.
Figure 7 is a diagram showing a short-circuited state of the switch unit when the first protective ground line is opened according to an embodiment of the present invention.
Figure 8 is a diagram showing a state in which the switch unit is opened when the first protective ground line is opened according to an embodiment of the present invention.
Figure 9 is a diagram illustrating the current flow when the switch unit is opened in the case of opening the second protective ground line according to an embodiment of the present invention.
Figure 10 is a diagram showing current flow in a state where the switch unit is short-circuited when the second protective ground line is opened according to an embodiment of the present invention.
Figure 11 is a flowchart for explaining a ground fault detection method according to an embodiment of the present invention.
FIG. 12 is a diagram showing step S1140 of FIG. 11 in detail.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

However, the technical idea of the present invention is not limited to some of the described embodiments, but may be implemented in various different forms, and as long as it is within the scope of the technical idea of the present invention, one or more of the components may be optionally used between the embodiments. It can be used by combining and replacing.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless explicitly specifically defined and described, are generally understood by those skilled in the art to which the present invention pertains. It can be interpreted as meaning, and the meaning of commonly used terms, such as terms defined in a dictionary, can be interpreted by considering the contextual meaning of the related technology.

Additionally, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

In this specification, the singular may also include the plural unless specifically stated in the phrase, and when described as "at least one (or more than one) of A and B and C", it is combined with A, B, and C. It can contain one or more of all possible combinations.

Additionally, when describing the components of an embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used.

These terms are only used to distinguish the component from other components, and are not limited to the essence, order, or order of the component.

And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to that other component, but also is connected to that component. It can also include cases where other components are 'connected', 'combined', or 'connected' due to another component between them.

Additionally, when described as being formed or disposed "above" or "below" each component, "above" or "below" refers not only to cases where two components are in direct contact with each other, but also to one This also includes cases where another component described above is formed or placed between two components. In addition, when expressed as "top (above) or bottom (bottom)", it may include not only the upward direction but also the downward direction based on one component.

1 is a diagram for explaining an electric vehicle charging system according to an embodiment of the present invention.

Referring to FIG. 1, an electric vehicle charging system according to an embodiment of the present invention may include an electric vehicle charging device (Electric Vehicle Supply Equipment, EVSE, 10) and an electric vehicle (Electric Vehicle, EV, 20).

The electric vehicle charging device 10 is a facility that supplies AC or DC, and can be placed at a charging station or within a home, and can also be implemented to be portable. The electric vehicle charging device 10 may be used interchangeably with a charging station (supply), an AC charging station (AC supply), a DC charging station (DC supply), a socket-outlet, etc.

The electric vehicle 20 can charge the battery provided in the vehicle from the electric vehicle charging device 10. To this end, the charging cable connected to the electric vehicle charging device 10 may be connected to the inlet of the electric vehicle 20. The electric vehicle 20 may be equipped with an electric vehicle charging controller (EVCC) for battery charging. A controller for charging an electric vehicle may communicate with the electric vehicle 20. The electric vehicle charging controller may communicate with the electric vehicle charging device 10. The electric vehicle charging controller may be connected to the electric vehicle 20 through a plurality of pins. The electric vehicle charging controller may be connected to the electric vehicle charging device 10 through a plurality of pins.

For example, the electric vehicle charging controller includes 20 pins connected to the electric vehicle charging device 10 and can communicate with the electric vehicle charging device 10 through this. For example, one of the 20 pins may be a CP port pin that receives a CP (Control Pilot) signal from the electric vehicle charging device 10, and the other pin may be a PD (Proximity Detection) pin that detects the proximity of the charging cable connector. One may be a pin for a port, and the other may be a pin for a protective earth (PE) port connected to the protective ground of the electric vehicle charging device 10. Another one of the 20 pins may be a pin for driving a motor to open the gas filler flap, another may be a pin for sensing the motor, another may be a pin for temperature sensing, and another pin may be a pin for sensing the temperature. Another may be a pin for LED sensing, and another may be a pin for CAN communication. However, the number and function of pins are not limited to this and may be modified in various ways.

In addition, the electric vehicle charging controller includes 12 pins connected to the electric vehicle 20, through which it can communicate with the electric vehicle 20. For example, one of the 12 pins may be a pin for a voltage line applied from a collision detection sensor within the electric vehicle 20, another may be a battery pin within the electric vehicle 20, and another pin may be a pin for can communication. It may be a pin, another may be a pin connected to ground, and another may be a high voltage protection pin. However, the number and function of pins are not limited to this and may be modified in various ways.

The two high voltage lines of the electric vehicle charging device 10 supply power to the battery of the electric vehicle 20 through the electric vehicle charging controller. At this time, the on and off of the high voltage lines is controlled by the electric vehicle charging controller. You can.

That is, the electric vehicle charging controller communicates with the ECU (Elctric Control Unit) of the electric vehicle 20 and charges the electric vehicle according to signals respectively received from at least one of the electric vehicle 20 or the electric vehicle charging device 10. The power supplied from the device 10 can be controlled to be transmitted to the battery of the electric vehicle 20.

The electric vehicle 20 may include a ground fault detection device 200 according to an embodiment of the present invention. The ground fault detection device 200 can detect a ground fault, such as an open protective ground line state. The ground fault detection device 200 detects errors in the protective ground line based on the charging control signal input to the electric vehicle charging controller and the proximity between the inlet of the electric vehicle 20 and the connector of the electric vehicle charging device 10. The open position can be detected. To this end, the ground fault detection device 200 may include a switch with one end connected to the protective ground terminal of the electric vehicle charging device 10. The detailed configuration of the ground fault detection device 200 will be examined through the drawings below.

Figures 2 to 4 are diagrams showing standard specifications for an electric vehicle charging system. Figure 2 is a diagram showing a proximity detection circuit according to Combined Charging System type 1 (CCS1).

As shown in Figure 2, proximity detection can be performed by connecting the connector of the electric vehicle charging device 10 and the pin 31 of the inlet of the electric vehicle 20, and the protective ground of the electric vehicle charging device 10 The terminal 33 and the chassis ground terminal 34 of the electric vehicle 20 may be connected through a pin 32. The switch unit according to an embodiment of the present invention may be disposed between the resistor R5 and the pin 32.

Figure 3 is a diagram showing integrated charging system type 2 (CCS2).

Referring to FIG. 3, the connector of the electric vehicle charging device 10 and the inlet of the electric vehicle 20 can perform proximity detection through connection to the pin 41, and the protective ground terminal of the electric vehicle charging device 10 43 and the chassis ground terminal 44 of the electric vehicle 20 may be connected through a pin 42. Although not shown in FIG. 3, the switch unit according to an embodiment of the present invention may be placed between the pin 42 and the control unit (EV Control Unit) 45 of the electric vehicle 20 that detects proximity.

Figure 4 is a diagram showing a CP (control pilot) circuit according to the DIN (Deutsches Institute further Normung) standard.

Referring to FIG. 4, the connector of the electric vehicle charging device 10 and the inlet of the electric vehicle 20 can transmit a control pilot signal, that is, a charging control signal, through connection to the pin 51, and in an embodiment of the present invention The ground fault detection device according to the present invention can detect the PWM duty ratio and voltage magnitude by analyzing the control pilot signal transmitted through the pin 51. The protective ground terminal 53 of the electric vehicle charging device 10 and the chassis ground terminal of the electric vehicle 20 may be connected through a pin 52. The ground fault detection device according to an embodiment of the present invention can be implemented through the on-board Battery Charge Controller 54.

Figure 5 is a configuration diagram of a ground fault detection device according to an embodiment of the present invention.

Referring to Figure 5, the ground fault detection device 200 according to an embodiment of the present invention includes a switch unit 210, a switch control unit 220, a proximity detection unit 230, a control signal analysis unit 240, and an error detection unit ( 250).

The switch unit 210 may be disposed between the electric vehicle charging device (EVSE) 10 and the electric vehicle 20. The switch unit 210 may be implemented as a switching element. The switch unit 210 includes a bipolar junction transistor (BJT), a unijunction transistor (UJT), a junction field effect transistor (JFET), and a metal oxide semiconductor field effect transistor. It can be implemented with any one of a Semiconductor Field Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), or an Injection-Enhanced Insulated Gate Transistor (IEGT). This is just an example, and may be implemented with other types of devices capable of performing a switching function.

The switch control unit 220 can control the switch unit 210. The switch control unit 220 may generate a switching control signal to control the switch unit 210. The generated switching control signal may be input to the switch control unit 220.

The switch control unit 220 may control the switch unit 210 to repeat opening and shorting according to a preset cycle. At this time, the preset cycle may be set differently depending on the electric vehicle charging device 10 and the electric vehicle 20. The preset cycle may be set within a range in which charging between the electric vehicle charging device 10 and the electric vehicle 20 is normally controlled.

The proximity detection unit 230 can detect whether the connector of the electric vehicle charging device 10 is close to the inlet of the electric vehicle 20.

If the magnitude of the voltage applied to the resistance included in the electrical closed loop formed by the electric vehicle charging device 10 and the electric vehicle 20 is greater than the preset voltage magnitude, the proximity detection unit 230 determines that the connector and the inlet are close. can do.

The control signal analysis unit 240 may detect the PWM duty ratio of the charging control signal and the voltage magnitude of the charging control signal. The charging control signal may be a PWM signal, and the power value charged to the battery of the electric vehicle 20 may be different depending on the PWM duty.

The error detection unit 250 determines the open position of the protective earth (PE) line of the electric vehicle 20 based on at least one of the PWM duty ratio of the charging control signal, the voltage magnitude of the charging control signal, and a determination result of proximity. can be detected.

The error detection unit 250 protects the electric vehicle 20 when the PWM duty ratio is within a preset first range and the voltage magnitude is within a preset second range while the switch unit 210 is open. It can be determined that the ground line is in a normal state. On the other hand, when the PWM duty ratio is not included in the preset first range and the voltage magnitude is not included in the preset second range while the switch unit 210 is open, the error detection unit 250 grounds the chassis of the electric vehicle 20. It may be determined that the first protective ground line connecting the (chassis ground) terminal and the protective ground terminal of the electric vehicle charging device 10 is in an open state.

If it is determined that the connector and the inlet are close to each other in a shorted state, the error detection unit 250 may determine that the protective ground line of the electric vehicle 20 is in a normal state. On the other hand, if the error detection unit 250 determines that the connector and the inlet are not close while the switch unit 210 is short-circuited, the proximity detection unit 230 of the electric vehicle 20 and the electric vehicle charging device 10 are protected. It may be determined that the second protective ground line connecting the ground terminal is open.

Figure 6 is a diagram for explaining the arrangement of the switch unit according to an embodiment of the present invention.

As shown in FIG. 6, the switch unit 210 may be disposed on a closed loop circuit formed by the electric vehicle charging device 10 and the electric vehicle 20. Specifically, the first terminal of the switch unit 210 may be connected to the protective earth (PE, 61) terminal of the electric vehicle charging device 10. The second end of the switch unit 210 may be connected to the proximity detection unit 230.

7 to 10 are diagrams for explaining the ground fault detection mechanism of the fault detection unit 250 according to an embodiment of the present invention.

Figure 7 shows a state in which the switch unit is short-circuited when the first protective ground line is opened according to an embodiment of the present invention. Figure 8 shows a state in which the switch unit is opened when the first protective ground line is opened according to an embodiment of the present invention.

7 and 8 show a state in which the first protective ground line connecting the chassis ground terminal of the electric vehicle 20 and the protective ground terminal of the electric vehicle charging device 10 is open.

As shown in FIG. 7 , when the switch unit 210 is short-circuited while the first protective ground line is open, it may be the same as the state where the switch unit 210 is not disposed and is connected by a conductive wire. In this case, it cannot be determined whether the first protective ground line is open. This is because the open state of the first protective ground line does not affect the formation of a closed loop including the protective ground line.

However, as shown in FIG. 8, when the switch unit 210 is opened while the first protective ground line is open, a closed loop connected to the protective ground of the electric vehicle charging device 10 is not formed. In this case, current flows to the chassis ground of the electric vehicle 20, and at this time, the charging control signal may have a different duty ratio and voltage magnitude from the charging control signal in FIG. 7.

For example, in the case of FIG. 7, the charging control signal may have a duty ratio of 5% and a voltage magnitude of 6 [V]. However, in the case of FIG. 8, the charging control signal may have a duty ratio of 10% and a voltage level of 12 [V].

According to this mechanism, when the PWM duty ratio is within a preset first range and the voltage level is within a preset second range while the switch unit 210 is open, the error detection unit 250 detects the electric vehicle 20 It can be determined that the first protective ground line connecting the chassis ground terminal of ) and the protective ground terminal of the electric vehicle charging device 10 is in a normal state. Conversely, when the switch unit 210 is open and the PWM duty ratio is not included in the preset first range and the voltage level is not included in the preset second range, the chassis ground terminal of the electric vehicle 20 and the electric vehicle 210 are connected to each other. It may be determined that the first protective ground line connecting the protective ground terminal of the automobile charging device 10 is in an open state.

The first range corresponding to the PWM duty ratio and the second range corresponding to the voltage magnitude may be set based on the case where the first protective ground line is in a normal state. For example, when the first protective ground line is in a normal state, the PWM duty ratio is 5% and the voltage magnitude is 6 [V], the first range may range from 4% to 6%, and the voltage magnitude is 5 [V]. It may range from [V] to 7 [V].

Figure 9 shows the current flow with the switch unit open in the case of opening the second protective ground line according to an embodiment of the present invention. Figure 10 shows the current flow in a state where the switch unit is short-circuited when the second protective ground line is opened according to an embodiment of the present invention.

As shown in FIG. 9, the open state of the switch unit 210 may be the same as the open state of the second protective ground line. In this case, since the proximity detection unit 230 determines that the connector and the inlet are not close, the error detection unit 250 determines whether the second protective ground line is open or the switch unit 210 is open. I can't.

However, as shown in FIG. 10, when the proximity detection unit 230 determines that the connector and the inlet are not close while the switch unit 210 is short-circuited, the error detection unit 250 detects that the second protective ground line is open. status can be determined.

According to this mechanism, when the error detection unit 250 determines that the connector and the inlet are close while the switch unit 210 is short-circuited, the proximity detection unit 230 of the electric vehicle 20 and the electric vehicle charging device 10 It can be determined that the second protective ground line connecting the protective ground terminal of is in a normal state. Conversely, if the error detection unit 250 determines that the connector and the inlet are not close while the switch unit 210 is short-circuited, it protects the proximity detection unit 230 of the electric vehicle 20 and the electric vehicle charging device 10. It may be determined that the second protective ground line connecting the ground terminal is open.

Figure 11 is a flowchart for explaining a ground fault detection method according to an embodiment of the present invention.

First, the ground fault detection device 200 may open and short the switch disposed between the electric vehicle charging device 10 and the electric vehicle 20 according to a preset cycle (S1110).

Then, the ground fault detection device 200 can detect whether the connector of the electric vehicle charging device 10 is close to the inlet of the electric vehicle 20 (S1110).

Additionally, the ground fault detection device 200 may detect the PWM duty ratio of the charging control signal and the voltage magnitude of the charging control signal (S1110).

Next, the ground fault detection device 200 determines the protective earth (PE) of the electric vehicle 20 based on at least one of the PWM duty ratio of the charging control signal, the voltage magnitude of the charging control signal, and the determination result of proximity. ) The open position of the line can be detected (S1110).

FIG. 12 is a diagram showing step S1140 of FIG. 11 in detail.

The ground fault detection device 200 may determine whether the PWM duty ratio is within a preset first range and the voltage magnitude is within a preset second range when the switch unit 210 is open ( S1141).

The ground fault detection device 200 grounds the chassis of the electric vehicle 20 when the PWM duty ratio is within a preset first range and the voltage magnitude is within a preset second range while the switch unit 210 is open. It may be determined that the first protective ground line connecting the (chassis ground) terminal and the protective ground terminal of the electric vehicle charging device 10 is in a normal state (S1142).

On the other hand, the ground fault detection device 200 operates when the PWM duty ratio is outside the preset first range and the voltage magnitude is outside the preset second range while the switch unit 210 is open, the first protective ground line is It can be determined that it is in an open state (S1143).

Additionally, the ground fault detection device 200 may determine whether the switch unit 210 is close based on the proximity detection result between the connector and the inlet in a shorted state (S1144).

If the ground fault detection device 200 determines that the connector and the inlet are close as a result of proximity detection while the switch unit 210 is short-circuited, the proximity detection unit 230 of the electric vehicle 20 and the electric vehicle charging device 10 It may be determined that the second protective ground line connecting the protective ground terminal is in a normal state (S1145).

On the other hand, if the ground fault detection device 200 determines that the connector and the inlet are not close as a result of proximity detection while the switch unit 210 is short-circuited, it may determine that the second protective ground line is in an open state. There is (S1146).

In Figure 12, steps S1141 to S1143 and steps S1144 to S1146 are shown to be performed together, but this is only an example. According to another embodiment, steps S1144 to S1146 may be performed after steps S1141 to S1143 are performed, or steps S1141 to S1143 may be performed after steps S1144 to S1146 are performed.

Although the above description focuses on the examples, this is only an example and does not limit the present invention, and those skilled in the art will be able to You will see that various variations and applications are possible. For example, each component specifically shown in the examples can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the appended claims.

10: Electric vehicle charging device
20: electric car
200: Ground fault detection device
210: switch part
220: switch control unit
230: Proximity detection unit
240: Control signal analysis unit
250: error detection unit

Claims (11)

A switch unit disposed between the electric vehicle charging equipment (EVSE) and the electric vehicle,
A switch control unit that controls the switch unit,
A proximity detection unit that detects whether a connector of the electric vehicle charging device is close to an inlet of the electric vehicle,
A control signal analysis unit that detects the PWM duty ratio of the charging control signal and the voltage magnitude of the charging control signal, and
An error detection unit that detects the open position of the protective earth (PE) line of the electric vehicle based on at least one of the PWM duty ratio of the charging control signal, the voltage magnitude of the charging control signal, and the proximity determination result. A ground fault detection device comprising: According to paragraph 1,
The switch unit,
The first stage is connected to the protective earth (PE) terminal of the electric vehicle charging device,
A ground fault detection device whose second stage is connected to the proximity detection unit. According to paragraph 1,
The switch control unit,
A ground fault detection device that controls the switch unit to repeat opening and shorting according to a preset cycle. According to paragraph 1,
The proximity detection unit,
A ground fault detection device that detects that the connector and the inlet are close when the magnitude of the voltage applied to the resistance included in the electric closed loop formed by the electric vehicle charging device and the electric vehicle is greater than a preset voltage magnitude. According to paragraph 1,
The error detection unit,
When the switch unit is open and the PWM duty ratio is within a preset first range and the voltage level is within a preset second range, the chassis ground terminal of the electric vehicle and the electric vehicle charging device A ground fault detection device that determines that the first protective ground line connecting the protective ground terminal is in a normal state. According to paragraph 1,
The error detection unit,
When the switch unit is open and the PWM duty ratio is not included in the preset first range and the voltage level is not included in the preset second range, the chassis ground terminal of the electric vehicle and the electric vehicle charging device are connected to each other. A ground fault detection device that determines that a first protective ground line connecting a protective ground terminal is in an open state. According to paragraph 1,
The error detection unit,
When it is determined that the connector and the inlet are close while the switch unit is short-circuited, it is determined that the second protective ground line connecting the proximity detection unit of the electric vehicle and the protective ground terminal of the electric vehicle charging device is in a normal state. Ground fault detection device. According to paragraph 1,
The error detection unit,
If it is determined that the connector and the inlet are not close to each other while the switch unit is short-circuited, the second protective ground line connecting the proximity detection unit of the electric vehicle and the protective ground terminal of the electric vehicle charging device is determined to be open. A ground fault detection device that makes judgments. Opening and short-circuiting a switch disposed between an electric vehicle charging equipment (EVSE) and an electric vehicle according to a preset cycle;
Detecting whether a connector of the electric vehicle charging device is close to an inlet of the electric vehicle,
Detecting the PWM duty ratio of the charging control signal and the voltage magnitude of the charging control signal, and
Detecting the open position of the protective earth (PE) line of the electric vehicle based on at least one of the PWM duty ratio of the charging control signal, the voltage magnitude of the charging control signal, and the determination result of the proximity. A ground fault detection method comprising: According to clause 9,
Detecting the open position of the protective ground line of the electric vehicle includes:
When the switch is open and the PWM duty ratio is not included in the preset first range and the voltage level is not included in the preset second range, the chassis ground terminal of the electric vehicle and the electric vehicle charging device A ground fault detection method for determining that a first protective ground line connecting a protective ground terminal is in an open state. According to clause 9,
Detecting the open position of the protective ground line of the electric vehicle includes:
If it is determined that the connector and the inlet are not close to each other while the switch is short-circuited, it is determined that the second protective ground line connecting the proximity detection unit of the electric vehicle and the protective ground terminal of the electric vehicle charging device is open. Ground fault detection method.