Leakage protection method and related product

Abstract

The embodiment of the invention provides an electric leakage protection method and related products, and the method comprises the steps: obtaining an electric signal between the two ends of a first electric leakage protection device, and carrying out the electric leakage protection operation if the failure of the first electric leakage protection device is determined according to the electric signal between the two ends of the first electric leakage protection device. The embodiment of the invention can reduce the electric leakage risk of the vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a leakage current protection method and related products. Background Technology

[0002] Currently, leakage protection devices are commonly used on subway, urban rail trains, monorails, trams and other vehicles to detect whether there is a leakage in the vehicle, but they have problems with low safety and reliability. Summary of the Invention

[0003] This application provides a leakage current protection method and related products, which can reduce the risk of leakage current in vehicles.

[0004] The first aspect of this application provides a leakage current protection method, including:

[0005] The electrical signal between the two ends of the first leakage current protection device is obtained. If the first leakage current protection device is determined to be faulty based on the electrical signal between the two ends of the first leakage current protection device, a signal to execute the leakage current protection action is issued.

[0006] In this embodiment, the failure of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device. In the event of the failure of the first leakage protection device, a signal to perform leakage protection action is issued. The leakage protection action can still be performed even when the first leakage protection device fails, thereby reducing the risk of leakage in the vehicle.

[0007] Optionally, the failure of the first leakage current protection device includes at least one of the following:

[0008] The first leakage protection device did not send a signal to execute leakage protection action;

[0009] The first leakage protection device is in the off state.

[0010] Optionally, issuing the signal to perform the leakage current protection action includes:

[0011] Send a signal to control the main circuit switch to open; and / or,

[0012] A signal is issued prohibiting the application of the first voltage to the vehicle.

[0013] Optionally, determining the failure of the first leakage current protection device based on the electrical signal between its two ends includes:

[0014] The failure of the first leakage current protection device is determined based on the voltage between the two ends of the first leakage current protection device and the state of the main circuit switch.

[0015] Optionally, determining the failure of the first residual current device based on the voltage between its two terminals and the state of the main circuit switch includes:

[0016] If the voltage between the two ends of the first leakage current protection device is greater than or equal to the first threshold for a duration longer than the first preset duration, and the main circuit switch is in the closed state, the first leakage current protection device is determined to be faulty.

[0017] Optionally, determining the failure of the first residual current device based on the voltage between its two terminals and the state of the main circuit switch includes:

[0018] When the voltage between the two ends of the first leakage protection device is greater than or equal to the first threshold, the status of the main circuit switch is detected.

[0019] If the main circuit switch does not disconnect within a first preset time period, it is determined that the first leakage protection device has not failed.

[0020] Optionally, determining the failure of the first leakage current protection device based on the electrical signal between its two ends includes:

[0021] In the case of a second voltage on the vehicle, the on / off state of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device, where the second voltage is less than the first voltage.

[0022] If the first leakage current protection device is in the off state, it is determined that the first leakage current protection device has failed.

[0023] Optionally, the method further includes:

[0024] If it is determined from the electrical signal between the two ends of the first leakage protection device that the first leakage protection device has not failed, a signal is issued to allow the first voltage on the vehicle.

[0025] Optionally, the method further includes:

[0026] When the vehicle is allowed to be supplied with a first voltage and an instruction to supply the first voltage is received, a signal is issued to control the main circuit switch to close; wherein, the first leakage protection device is used to detect whether the vehicle is leaking current when the main circuit switch is closed, and to trigger the main circuit switch to open when the leakage current is detected.

[0027] Optionally, determining the on / off state of the first leakage current protection device based on the electrical signal between its two ends includes:

[0028] When the main circuit switch is open, the on / off state of the first leakage current protection device is determined based on the electrical signal between the two ends of the first leakage current protection device.

[0029] Optionally, determining the on / off state of the first leakage current protection device based on the electrical signal between its two ends includes:

[0030] When an electrical signal is received at one end of the first leakage current protection device and an electrical signal is output at the other end of the first leakage current protection device, it is determined that the first leakage current protection device is in a conducting state.

[0031] If an electrical signal is received at one end of the first leakage current protection device and no electrical signal is output at the other end of the first leakage current protection device, it is determined that the first leakage current protection device is in the off state.

[0032] Optionally, determining the failure of the first leakage current protection device based on its on / off state includes:

[0033] If the first leakage current protection device is in the off state, it is determined that the first leakage current protection device has failed.

[0034] Optionally, the method further includes:

[0035] When the first voltage on the vehicle is blocked, the first leakage protection device is restarted, and the failure of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device.

[0036] Optionally, the method further includes:

[0037] In the event of failure of the first leakage current protection device, an alarm message indicating the failure of the first leakage current protection device is sent to the central control unit.

[0038] Optionally, the method further includes:

[0039] In the event of failure of the first leakage protection device, a leakage alarm message is sent to the central control unit.

[0040] Optionally, the method further includes:

[0041] If the first leakage current protection device is not malfunctioning, a normal feedback message from the first leakage current protection device is sent to the central control unit.

[0042] A second aspect of this application provides an electronic device including a processor and a memory, the memory being used to store a computer program, the computer program including program instructions, and the processor being configured to invoke the program instructions to execute the step instructions as described in the first aspect of this application.

[0043] A third aspect of this application provides a computer-readable storage medium storing a computer program for electronic data interchange, wherein the computer program causes a computer to perform some or all of the steps described in the first aspect of this application.

[0044] A fourth aspect of this application provides a computer program product, wherein the computer program product includes a computer program operable to cause a computer to perform some or all of the steps described in the first aspect of this application. The computer program product may be a software installation package.

[0045] A fifth aspect of this application provides a vehicle including electronic devices as described in a second aspect of this application.

[0046] Optionally, the vehicle further includes a central control unit, which establishes a communication connection with the electronic device;

[0047] The central control unit is used to receive alarm information about the failure of the first leakage current protection device sent by the electronic device in the event of failure of the first leakage current protection device.

[0048] In this embodiment, the failure of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device. In the event of the failure of the first leakage protection device, a signal to perform leakage protection action is issued. The leakage protection action can still be performed even when the first leakage protection device fails, thereby reducing the risk of leakage in the vehicle and improving the safety and reliability of leakage protection. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the structure of a leakage current protection system provided in an embodiment of this application;

[0051] Figure 2This is a schematic diagram of the specific structure of a leakage current protection system provided in an embodiment of this application;

[0052] Figure 3 This is a schematic diagram of the specific structure of another leakage current protection system provided in the embodiments of this application;

[0053] Figure 4 This is a schematic flowchart of a leakage current protection method provided in an embodiment of this application;

[0054] Figure 5 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application;

[0055] Figure 6 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application;

[0056] Figure 7 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application;

[0057] Figure 8 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application;

[0058] Figure 9 This is a schematic flowchart of a leakage current protection method provided in an embodiment of this application;

[0059] Figure 10 This is a schematic diagram of the specific process of another leakage current protection method provided in the embodiments of this application;

[0060] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0063] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0064] Please see Figure 1 , Figure 1 This is a schematic diagram of a leakage current protection system provided in an embodiment of this application, as shown below. Figure 1 As shown, the leakage current protection system includes a control unit and a detection device, with the input terminal of the control unit connected to the output terminal of the detection device;

[0065] The control unit is used to acquire the electrical signal between the two ends of the first leakage current protection device through the detection device, and determine whether the first leakage current protection device has failed based on the electrical signal between the two ends of the first leakage current protection device.

[0066] The control unit is also used to issue a signal to perform leakage protection action in the event of a malfunction of the first leakage protection device.

[0067] The detection device has a first detection terminal connected to the first terminal of the first leakage current protection device (RCD), and a second detection terminal connected to the second terminal of the RCD. The detection device can detect the electrical signals between the two terminals of the RCD. The control unit obtains the electrical signals between the two terminals of the RCD through the detection device and determines whether the RCD has failed based on these signals. For example, the detection device can detect the voltage between the two terminals of the RCD and output this voltage through its output terminal. The control unit obtains this voltage through its input terminal and determines whether the RCD has failed based on it. Alternatively, the detection device can detect whether the two terminals of the RCD are conducting. If the terminals are conducting, the detection device outputs a high-level signal to the control unit, indicating that the RCD is not failed. If the terminals are disconnected, the detection device outputs a low-level signal to the control unit, indicating that the RCD has failed.

[0068] The leakage protection action may include at least one of the following: prohibiting the vehicle from being powered on at high voltage, and disconnecting the main circuit switch.

[0069] "Vehicle high-voltage power-on" refers to the initial voltage applied to the vehicle. Specifically, it means energizing modules within the vehicle that require high-voltage power. Generally, this initial voltage is above 100V. Modules requiring high-voltage power can include: traction inverters, auxiliary converters, air conditioning units, etc.

[0070] The control unit can be a vehicle-mounted control unit, such as the traction control unit (TCU). The TCU can be used to control electrically driven equipment, achieving efficient traction and braking. The TCU can also perform fault diagnosis, quickly identifying the root cause of a fault after it occurs, thus helping to resolve the problem rapidly.

[0071] The first type of leakage protection device is the leakage protection device installed on the vehicle, which can also be called the vehicle leakage protection device.

[0072] In this embodiment, the control unit can obtain the electrical signal between the two ends of the first leakage protection device through the detection device, determine the failure of the first leakage protection device based on the electrical signal between the two ends of the first leakage protection device, and issue a signal to perform leakage protection action when the first leakage protection device fails. The leakage protection action can still be performed when the first leakage protection device fails, thereby reducing the risk of leakage in the vehicle and improving the safety and reliability of leakage protection.

[0073] Optionally, the detection device may include a voltage sensor, with the input terminal of the control unit connected to the output terminal of the voltage sensor, the first sampling terminal of the voltage sensor connected to the first terminal of the first leakage current protection device, and the second sampling terminal of the voltage sensor connected to the second terminal of the first leakage current protection device.

[0074] The voltage sensor is used to collect the voltage across the two ends of the first leakage protection device;

[0075] The control unit determines whether the first leakage current protection device has failed based on the electrical signal between the two ends of the first leakage current protection device, including:

[0076] The control unit determines whether the first leakage current protection device has failed based on the voltage between the two ends of the first leakage current protection device.

[0077] Among them, the voltage sensor can be a voltage Hall sensor, which has the characteristics of high accuracy and fast response.

[0078] Optionally, the leakage protection system further includes a main circuit switch, which is connected in series between the positive terminal of the power grid and the high-voltage positive terminal of the vehicle.

[0079] The main circuit switch can be a switch that allows large current to pass through. For example, the main circuit switch can be a high-speed circuit breaker (HSCB).

[0080] In one possible embodiment, the control unit may be a traction control unit, and the detection device may be a voltage sensor. See also... Figure 2 , Figure 2 This is a schematic diagram of the specific structure of a leakage current protection system provided in an embodiment of this application. Figure 2 As shown, the leakage protection system includes a traction control unit and a voltage sensor (such as...). Figure 2 The HV shown) and main circuit switch (such as Figure 2 The voltage sensor has two sampling terminals (first sampling terminal and second sampling terminal) connected to the vehicle's high-voltage negative terminal and the vehicle body ground (wherein the vehicle body ground is the grounding part connected to the vehicle body) respectively. The two ends of the first leakage protection device are connected to the vehicle's high-voltage negative terminal and the vehicle body ground respectively (that is, the first leakage protection device is connected in series between the vehicle's high-voltage negative terminal and the vehicle body ground). The main circuit switch is connected in series between the grid positive terminal and the vehicle's high-voltage positive terminal. The input terminal of the traction control unit is connected to the output terminal of the voltage sensor.

[0081] The voltage sensor is used to collect the voltage across the two ends of the first leakage protection device;

[0082] The traction control unit is configured to determine whether the first leakage protection device has failed based on the voltage between the two ends of the first leakage protection device; and to control the main circuit switch to open when the first leakage protection device fails and the main circuit switch is closed.

[0083] The main circuit switch is connected in series between the positive terminal of the power grid and the high-voltage positive terminal of the vehicle. When the main circuit switch is closed, the vehicle can draw power from the positive terminal of the power grid; when the main circuit switch is open, the vehicle cannot draw power from the positive terminal of the power grid.

[0084] Figure 2 It also includes a positive and a negative current collector. The vehicle's high-voltage positive terminal draws power from the positive terminal of the power grid through the main circuit switch and the positive current collector, while the vehicle's high-voltage negative terminal draws power from the negative terminal of the power grid through the negative current collector. The positive and negative terminals of the power grid can provide high-voltage direct current to the vehicle. The positive and negative current collectors can be components on the pantograph or the conductive rail. For example, if the vehicle is a subway or high-speed rail, power is drawn from the pantograph. If the vehicle is a monorail, power is drawn from the conductive rail.

[0085] Optional, Figure 2 It also includes multiple loads (such as) Figure 2The loads shown (load 1, load 2, load 3, etc.) require high-voltage power. The positive terminal of each load is connected to the vehicle's high-voltage positive terminal, and the negative terminal is connected to the vehicle's high-voltage negative terminal. Load 1, load 2, and load 3 refer to electrical equipment on the vehicle, such as traction inverters, auxiliary converters, and air conditioners.

[0086] When a vehicle experiences an electrical leakage, the electrical insulation between the vehicle's high-voltage positive terminal and the vehicle body (i.e., the vehicle's ground) fails or short-circuits, causing the vehicle body to become electrified. At this point, the vehicle body and the vehicle's high-voltage positive terminal are at the same potential, while a voltage difference exists between the vehicle body and the vehicle's high-voltage negative terminal. If a person touches the vehicle body, they will experience an electric shock.

[0087] In this embodiment, the voltage sensor can collect the voltage between the vehicle's high-voltage negative terminal and the vehicle body ground. By using the voltage sensor to promptly determine whether a leakage has occurred in the vehicle, the main circuit switch can be shut off in a timely manner when a leakage is detected, thereby reducing the risk of electric shock to the vehicle.

[0088] Figure 2 The leakage protection system also includes a first switch KA1 and a second switch KA2; the control terminal of the first switch KA1 is connected to the second output terminal of the traction control unit, the first terminal of the second switch KA2 is connected to the first detection terminal of the traction control unit, and the second terminal of the second switch KA2 is connected to the second detection terminal of the traction control unit.

[0089] The first switch KA1 is connected in series with the main circuit switch (e.g., Figure 2 The control circuit of the HSCB shown is such that the second switch KA2 is connected in series in the detection circuit of the control unit (i.e., Figure 2 The detection circuit 1 shown; when the main circuit switch is open, the second switch KA2 is open; when the main circuit switch is closed, the second switch KA2 is closed. The detection circuit of the control unit can be the first detection circuit of the control unit.

[0090] In this embodiment, the state of the first switch KA1 and the state of the second switch KA2 are related. If the first switch KA1 is open, the second switch KA2 is open; if the first switch KA1 is closed, the second switch KA2 is closed.

[0091] The first switch KA1 is connected in series in the control circuit of the main circuit switch. When the first switch KA1 is open, the main circuit switch is also open. The second switch KA2 is connected in series in the first detection circuit of the traction control unit. The traction control unit can detect the state of the second switch KA2 through the first detection circuit, thereby detecting the state of the main circuit switch.

[0092] Optional, such as Figure 2As shown, the first leakage protection device includes: a grounding switch QS, a leakage detection resistor GR, a second diode D2, and a leakage detection unit LDU. The first terminal of the grounding switch QS is connected to the high-voltage negative terminal of the vehicle. The second terminal of the grounding switch QS is connected to the first terminal of the leakage detection resistor GR and the first terminal of the leakage detection unit LDU. The second terminal of the leakage detection resistor GR is connected to the second terminal of the leakage detection unit LDU and the negative terminal of the second diode D2. The positive terminal of the second diode D2 is connected to the vehicle ground. The leakage detection unit LDU is used to detect the voltage across the leakage detection resistor GR.

[0093] The failure of the first leakage protection device may include at least one of the following situations: the leakage detection resistor GR is damaged, the second diode D2 is damaged, or the grounding switch QS is not closed.

[0094] If there is an electrical insulation failure or short circuit between the vehicle's high-voltage positive terminal and the vehicle body (i.e., the vehicle body ground), a leakage current will occur, causing the vehicle body to become energized. At this time, the vehicle body and the vehicle's high-voltage positive terminal are at the same potential, and a voltage difference is generated between the vehicle body and the vehicle's high-voltage negative terminal. The first leakage protection device determines whether a leakage current has occurred based on this voltage difference.

[0095] The first leakage current protection device is connected between the vehicle body ground and the vehicle's high-voltage negative terminal. This device includes a leakage detection resistor GR connected in series between the vehicle body ground and the vehicle's high-voltage negative terminal, a grounding switch QS, a second diode D2, and a leakage detection unit LDU. The grounding switch QS is normally closed and is only manually opened during vehicle insulation measurements or other maintenance work to avoid affecting the detection results. The second diode D2 blocks the connection between the vehicle's high-voltage negative terminal and the vehicle body ground. The leakage detection unit LDU detects the voltage across the leakage detection resistor GR. When the voltage across the leakage detection resistor GR exceeds a first threshold, it is determined that leakage has occurred at the vehicle's high-voltage positive terminal, and the leakage protection action is activated.

[0096] Optional, such as Figure 2 As shown, the leakage current detection unit (LDU) includes an overvoltage protection relay, which is connected in parallel across the leakage current detection resistor GR. The overvoltage protection relay includes a third switch KA3 and a fourth switch KA4. (It should be noted that...) Figure 2 Although KA3 and KA4 are not drawn in the LDU, they are components of the LDU. The third switch KA3 is connected in series with the main circuit switch. Figure 2 The control circuit of the main circuit switch (taking HSCB as an example) is such that the fourth switch KA4 is connected in series in the second detection circuit of the traction control unit (i.e., Figure 2 The detection loop 2 shown is shown.

[0097] When the voltage across the leakage current detection resistor GR is greater than or equal to the second threshold, the third switch KA3 is opened to disconnect the main circuit switch; the fourth switch KA4 is closed to allow the traction control unit to detect the leakage current protection action generated by the leakage current detection unit LDU.

[0098] When the voltage across the leakage current detection resistor GR is less than the second threshold, the third switch KA3 closes and the fourth switch KA4 opens.

[0099] In this embodiment, the second threshold can be preset and stored in the memory of the traction control unit (e.g., non-volatile memory). The second threshold can be set to be equal to or unequal to the first threshold. For example, both the first and second thresholds can be set to 100V.

[0100] Figure 2 The first leakage protection device, voltage sensor HV, HSCB, third switch KA3 and fourth switch KA4 can be components of the vehicle's electrical distribution box.

[0101] Optional, such as Figure 2 As shown, the leakage protection system also includes a second leakage protection device, one end of which is connected to the negative terminal of the power grid, and the other end of which is connected to the grounding part of the distribution cabinet.

[0102] The second leakage current protection device is used to disconnect the power supply to the vehicle when the duration of leakage current detected by the second leakage current protection device at the positive terminal of the power grid exceeds a second preset duration, wherein the second preset duration is longer than the first preset duration. The grounding point of the distribution cabinet can be the cabinet body of the distribution cabinet.

[0103] In this embodiment, the second leakage current protection device is a ground-mounted leakage current protection device. Specifically, the second leakage current protection device can be installed in a ground-mounted distribution cabinet, which can provide power to all vehicles on the track. The second leakage current protection device can detect whether leakage has occurred at the positive terminal of the power grid. When the second leakage current protection device detects leakage at the positive terminal of the power grid, it will not immediately disconnect the power supply to the vehicle's power grid, that is, it will not allow the positive terminal of the power grid to lose power. The power supply to the vehicle's power grid will only be disconnected if the duration of the detected leakage at the positive terminal of the power grid exceeds a second preset duration. The leakage at the positive terminal of the power grid may be due to leakage at the high-voltage positive terminal of the vehicle. The power supply to the vehicle's power grid can only be disconnected after the vehicle's traction control unit determines whether the first leakage current protection device has failed, that is, when the second leakage current protection device detects that the duration of the detected leakage at the positive terminal of the power grid exceeds the second preset duration. Before disconnecting the power supply to the vehicle's power grid, it is possible to accurately determine whether the first leakage current protection device has failed, reducing the difficulty of fault diagnosis and thus improving the speed of subsequent maintenance.

[0104] The second preset duration can be set in advance and stored in the memory of the traction control unit (e.g., non-volatile memory).

[0105] For example, the first preset duration can be set to 200 milliseconds (ms), and the second preset duration can be set to 400 ms.

[0106] The second leakage protection device may include a grounding leakage protection device (such as...) Figure 2 The 64D and the third diode D3 are shown. The first terminal of the grounding leakage protection device is connected to the negative terminal of the power grid, the second terminal of the grounding leakage protection device is connected to the negative terminal of the third diode D3, and the positive terminal of the third diode D3 is connected to the grounding part of the distribution cabinet.

[0107] When a leakage occurs at the positive terminal of the power grid, the electrical insulation between the positive terminal of the power grid and the grounding part of the distribution cabinet fails or short-circuits, resulting in a leakage phenomenon that energizes the grounding part of the distribution cabinet. At this time, the grounding part of the distribution cabinet is at the same potential as the positive terminal of the power grid, and a voltage difference is generated between the grounding part of the distribution cabinet and the negative terminal of the power grid. The grounding leakage protection device can detect this voltage difference, thereby disconnecting the power supply to the positive terminal of the power grid, and thus disconnecting the vehicle's power grid supply.

[0108] In one possible embodiment, the control unit may be a traction control unit, and the detection device may be a detection circuit. See also... Figure 3 , Figure 3 This is a schematic diagram of another leakage current protection system provided in an embodiment of this application. For example... Figure 3As shown, the leakage protection system includes a traction control unit and a detection circuit; the input terminal P1 of the traction control unit is connected to the output terminal of the detection circuit, the first output terminal P2 of the traction control unit is connected to the input terminal of the detection circuit, the first detection terminal of the detection circuit is connected to the first terminal of the first leakage protection device, and the second detection terminal of the detection circuit is connected to the second terminal of the first leakage protection device; wherein, the first terminal of the first leakage protection device is the vehicle's high-voltage negative terminal, and the second terminal of the first leakage protection device is the vehicle's ground.

[0109] The traction control unit is used to send a detection signal through its first output terminal P2 and to determine whether the first leakage current protection device has failed based on the signal received through its input terminal P1. Specifically, if the signal received through the input terminal P1 of the traction control unit is a high-level signal, it is determined that the first leakage current protection device has not failed; if the signal received through the input terminal P1 of the traction control unit is a low-level signal, it is determined that the first leakage current protection device has failed.

[0110] The detection signal can be a voltage signal (such as a voltage pulse signal). A high-level signal can be a signal with a voltage greater than a set threshold, and a low-level signal can be a signal with a voltage less than a set threshold. For example, the voltage signal can be a 5V signal, and the set threshold can be set to 3V.

[0111] In this embodiment, the traction control unit can actively send a detection signal to determine whether the first leakage current protection device has failed, thereby actively detecting whether the first leakage current protection device has failed. The traction control unit can detect whether the first leakage current protection device has failed at any time when it is necessary.

[0112] For example, the traction control unit can detect whether the first leakage protection device has failed when the vehicle is powered on at low voltage.

[0113] Low-voltage power-on refers to the second voltage applied to the vehicle, which is lower than the first voltage. Vehicle low-voltage power-on means that modules within the vehicle requiring low-voltage power are powered on. Generally, the second voltage is between 3V and 20V. Modules requiring low-voltage power may include the traction control unit.

[0114] Optional, Figure 3 The residual current protection system also includes a main circuit switch, which is connected in series between the positive terminal of the power grid and the high-voltage positive terminal of the vehicle. The main circuit switch can be a switch that allows large current to pass through. For example, the main circuit switch can be a high-speed circuit breaker (HSCB).

[0115] Optional, Figure 3 It also includes a positive and a negative current collector. The vehicle's high-voltage positive terminal draws power from the positive terminal of the power grid through the main circuit switch and the positive current collector, while the vehicle's high-voltage negative terminal draws power from the negative terminal of the power grid through the negative current collector. The positive and negative terminals of the power grid can provide high-voltage direct current to the vehicle. The positive and negative current collectors can be components on the pantograph or the conductive rail. For example, if the vehicle is a subway or high-speed rail, power is drawn from the pantograph. If the vehicle is a monorail, power is drawn from the conductive rail.

[0116] Optional, Figure 3 It also includes multiple loads (such as) Figure 1 As shown in the diagram (load 1, load 2, load 3, etc.), the positive terminal of each load is connected to the vehicle's high-voltage positive terminal, and the negative terminal is connected to the vehicle's high-voltage negative terminal. Load 1, load 2, and load 3 refer to electrical equipment on the vehicle, such as traction inverters, auxiliary converters, and air conditioners.

[0117] When a vehicle experiences an electrical leakage, the electrical insulation between the vehicle's high-voltage positive terminal and the vehicle body (i.e., the vehicle's ground) fails or short-circuits, causing the vehicle body to become electrified. At this point, the vehicle body and the vehicle's high-voltage positive terminal are at the same potential, while a voltage difference exists between the vehicle body and the vehicle's high-voltage negative terminal. If a person touches the vehicle body, they will experience an electric shock.

[0118] Before the vehicle's high-voltage power is applied, after the traction control unit is powered on, it can detect whether the first leakage protection device has failed. The traction control unit is powered by low-voltage electricity, and powering on the traction control unit can result in the vehicle being powered by low-voltage electricity.

[0119] When the first residual current device (RCD) is working normally, applying a voltage between its second terminal and its first terminal will allow the first and second terminals to conduct. When the first RCD fails, even if a voltage is applied between its second and first terminals, the first and second terminals will not conduct.

[0120] Optional, such as Figure 3 As shown, the leakage protection system also includes a second leakage protection device;

[0121] The second leakage protection device is used to disconnect the power supply to the vehicle when the duration of leakage at the positive terminal of the power grid exceeds a second preset duration.

[0122] In this embodiment, the second leakage current protection device is a ground-mounted leakage current protection device. Specifically, the second leakage current protection device can be installed in a ground-mounted distribution cabinet, which can provide power to all vehicles on the track. The second leakage current protection device can detect whether leakage has occurred at the positive terminal of the power grid. When the second leakage current protection device detects leakage at the positive terminal of the power grid, it will not immediately disconnect the power supply to the vehicle, that is, it will not allow the positive terminal of the power grid to lose power. The power supply to the vehicle will only be disconnected if the duration of the detected leakage at the positive terminal of the power grid exceeds a second preset duration. The leakage at the positive terminal of the power grid may be due to leakage at the high-voltage positive terminal of the vehicle, that is, the power supply to the vehicle will only be disconnected when the duration of the detected leakage at the positive terminal of the power grid exceeds the second preset duration. Before disconnecting the power supply to the vehicle, it is possible to accurately determine that the first leakage current protection device has malfunctioned, reducing the difficulty of fault diagnosis and thus improving the speed of subsequent maintenance.

[0123] For example, the second preset duration can be set to 400 milliseconds (ms).

[0124] The second leakage protection device may include a grounding leakage protection device (such as...) Figure 3 The 64D and the third diode D3 are shown. The first terminal of the grounding leakage protection device is connected to the negative terminal of the power grid, the second terminal of the grounding leakage protection device is connected to the negative terminal of the third diode D3, and the positive terminal of the third diode D3 is connected to the grounding part of the distribution cabinet.

[0125] When a leakage occurs at the positive terminal of the power grid, the electrical insulation between the positive terminal of the power grid and the grounding part of the distribution cabinet fails or short-circuits, resulting in a leakage phenomenon that energizes the grounding part of the distribution cabinet. At this time, the grounding part of the distribution cabinet is at the same potential as the positive terminal of the power grid, and a voltage difference is generated between the grounding part of the distribution cabinet and the negative terminal of the power grid. The grounding leakage protection device can detect this voltage difference, thereby disconnecting the power supply to the positive terminal of the power grid, and thus disconnecting the vehicle's power grid supply.

[0126] Optional, Figure 3 The first leakage current protection device includes: a grounding switch QS, a leakage current detection resistor GR, a second diode D2, and a leakage current detection unit LDU. The first terminal of the grounding switch QS is connected to the high-voltage negative terminal of the vehicle. The second terminal of the grounding switch QS is connected to the first terminal of the leakage current detection resistor GR and the first terminal of the leakage current detection unit LDU. The second terminal of the leakage current detection resistor GR is connected to the second terminal of the leakage current detection unit LDU and the negative terminal of the second diode D2. The positive terminal of the second diode D2 is connected to the vehicle ground. The leakage current detection unit LDU is used to detect the voltage across the leakage current detection resistor GR.

[0127] The failure of the first leakage protection device may include at least one of the following situations: the leakage detection resistor GR is damaged, the second diode D2 is damaged, or the grounding switch QS is not closed.

[0128] If there is an electrical insulation failure or short circuit between the vehicle's high-voltage positive terminal and the vehicle body (i.e., the vehicle body ground), a leakage current will occur, causing the vehicle body to become energized. At this time, the vehicle body and the vehicle's high-voltage positive terminal are at the same potential, and a voltage difference is generated between the vehicle body and the vehicle's high-voltage negative terminal. The first leakage protection device determines whether a leakage current has occurred based on this voltage difference.

[0129] The first leakage current protection device is connected between the vehicle body ground and the vehicle's high-voltage negative terminal. This device includes a leakage detection resistor GR connected in series between the vehicle body ground and the vehicle's high-voltage negative terminal, a grounding switch QS, a second diode D2, and a leakage detection unit LDU. The grounding switch QS is normally closed and is only manually opened during vehicle insulation measurements or other maintenance work to avoid affecting the test results. The second diode D2 blocks the connection between the vehicle's high-voltage negative terminal and the vehicle body ground. The leakage detection unit LDU detects the voltage across the leakage detection resistor GR. When the voltage U across the leakage detection resistor GR exceeds a set value, it is determined that leakage has occurred at the vehicle's high-voltage positive terminal, and the leakage protection action is activated.

[0130] Optional, such as Figure 3 As shown, the leakage current detection unit (LDU) includes an overvoltage protection relay. Figure 3 (Not shown in the image), the overvoltage protection relay is connected in parallel across the leakage current detection resistor GR, and the overvoltage protection relay includes a third switch KA3 and a fourth switch KA4 (it should be noted that...). Figure 3 Although KA3 and KA4 are not drawn in the LDU, they are components of the LDU. The third switch KA3 is connected in series with the main circuit switch. Figure 3 The control circuit of the main circuit switch (taking HSCB as an example) is such that the fourth switch KA4 is connected in series in the second detection circuit of the traction control unit (i.e., Figure 3 The detection loop 2 shown is shown.

[0131] The voltage U across the leakage current detection resistor GR is greater than or equal to the second threshold (i.e. Figure 3 When the set value is obtained, the third switch KA3 is opened to disconnect the HSCB; the fourth switch KA4 is closed to allow the traction control unit to detect the leakage protection action generated by the leakage detection unit LDU.

[0132] When the voltage across the leakage current detection resistor GR is less than the second threshold, the third switch KA3 closes and the fourth switch KA4 opens.

[0133] In this embodiment, the second threshold can be preset and stored in the memory of the traction control unit (e.g., non-volatile memory). For example, the second threshold can be set to 100V.

[0134] The specific implementation process of the leakage current protection is as follows: The overvoltage protection relay included in the leakage current detection unit (LDU) is connected in parallel across the leakage current detection resistor GR. The overvoltage protection relay includes a third switch KA3 and a fourth switch KA4. If the voltage across the leakage current detection resistor GR is greater than the second threshold, the overvoltage protection relay activates, the third switch KA3 opens, causing the HSCB control circuit to disconnect, thereby controlling the HSCB to disconnect. Simultaneously, it triggers the fourth switch KA4 to close. After the traction control unit detects the closing signal of the fourth switch KA4 through the second detection circuit, it determines that the vehicle has a leakage current and outputs leakage current alarm information to the central control unit.

[0135] The state of the third switch KA3 is related to the state of the fourth switch KA4. If the third switch KA3 is open, the fourth switch KA4 is closed; if the third switch KA3 is closed, the fourth switch KA4 is open.

[0136] The third switch KA3 is connected in series with the control circuit of the HSCB. When the third switch KA3 is open, the HSCB is disconnected. The fourth switch KA4 is connected in series with the second detection circuit of the traction control unit. The traction control unit can detect the state of the fourth switch KA4 through the second detection circuit, thereby detecting whether the leakage current detection unit (LDU) has implemented leakage current protection.

[0137] For example, the second detection circuit includes a circuit consisting of a second output terminal of the traction control unit, a first terminal of the fourth switch KA4, a second terminal of the fourth switch KA4, and a second input terminal of the traction control unit. The second output terminal of the traction control unit is connected to the first terminal of the fourth switch KA4, and the second terminal of the fourth switch KA4 is connected to the second input terminal of the traction control unit. When the fourth switch KA4 is closed, the second detection circuit is activated, and the traction control unit detects that the fourth switch KA4 is closed by means of the activation of the second detection circuit. When the fourth switch KA4 is open, the second detection circuit is deactivated, and the traction control unit detects that the fourth switch KA4 is open by means of the deactivation of the second detection circuit.

[0138] Optional, such as Figure 3 As shown, the leakage protection system also includes a first switch KA1 and a second switch KA2; the control terminal of the first switch KA1 is connected to the second output terminal of the traction control unit, the first terminal of the second switch KA2 is connected to the first detection terminal of the traction control unit, and the second terminal of the second switch KA2 is connected to the second detection terminal of the traction control unit.

[0139] The first switch KA1 is connected in series in the control circuit of the HSCB, and the second switch KA2 is connected in series in the detection circuit of the control unit (i.e., Figure 3 The detection circuit shown is 1); when the HSCB is open, the second switch KA2 is open; when the HSCB is closed, the second switch KA2 is closed. The detection circuit of the control unit can be the first detection circuit of the control unit.

[0140] In this embodiment, the state of the first switch KA1 and the state of the second switch KA2 are related. If the first switch KA1 is open, the second switch KA2 is open; if the first switch KA1 is closed, the second switch KA2 is closed.

[0141] The first switch KA1 is connected in series in the control circuit of the HSCB. When the first switch KA1 is open, the HSCB is disconnected. The second switch KA2 is connected in series in the first detection circuit of the traction control unit. The traction control unit can detect the state of the second switch KA2 through the first detection circuit, thereby detecting the state of the main circuit switch. Figure 3 The main circuit switch is HSCB as an example.

[0142] Both the first switch KA1 and the third switch KA3 are connected in series to the HSCB control circuit. Opening either the first switch KA1 or the third switch KA3 will cause the main circuit switch to open. Closing both the first switch KA1 and the third switch KA3 will cause the main circuit switch to close.

[0143] The HSCB control circuit, the first detection circuit of the traction control unit, and the second detection circuit of the traction control unit are all low-voltage circuits. The traction control unit is powered by low voltage, which facilitates its control of the first switch KA1 and its detection of the states of the second and fourth switches KA2 and KA4. The traction control unit can detect these states through the first detection circuit (e.g., Figure 3 The detection circuit 1 shown detects the state of the second switch KA2, thereby detecting the state of the HSCB. The traction control unit can detect the state of the HSCB through the second detection circuit (such as...). Figure 3 The detection circuit 2) shown detects the state of the fourth switch KA4, thereby detecting whether the leakage current detection unit LDU has implemented leakage current protection.

[0144] It should be noted that the HSCB is connected in series between the positive terminal of the power grid and the high-voltage positive terminal of the vehicle, placing the HSCB in a high-voltage circuit. Since the traction control unit is powered by low voltage, it cannot directly detect the state of the HSCB. Therefore, the state of the HSCB is detected by setting a correlation between the HSCB and the second switch KA2, and by detecting the state of the second switch KA2.

[0145] Figure 3The first leakage protection device, detection circuit, HSCB, third switch KA3 and fourth switch KA4 can be components of the vehicle's electrical distribution box.

[0146] Optionally, the traction control unit is also configured to control the HSCB to disconnect via the first switch KA1 before the vehicle is powered on with high voltage.

[0147] In this embodiment, when the first switch KA1 is open, the control circuit of the HSCB is disconnected, thereby causing the HSCB to disconnect. The traction control unit can control the HSCB to disconnect by controlling the first switch KA1 to disconnect. For example, the first terminal of the first switch KA1 is connected to the negative terminal of a power supply (e.g., a 110V power supply), and the control terminal of the first switch KA1 is connected to the second output terminal of the control unit. When the control terminal of the traction control unit outputs a positive voltage from the power supply, the first switch KA1 is closed; when the control terminal of the traction control unit outputs a negative voltage from the power supply, the first switch KA1 is open.

[0148] Optionally, the traction control unit is also configured to detect the status of the HSCB via the second switch KA2.

[0149] In this embodiment, since the state of the second switch KA2 is related to the state of HSCB, when HSCB is open, the second switch KA2 is open; when HSCB is closed, the second switch KA2 is closed. The traction control unit detects the second switch via the first detection circuit (e.g., ...). Figure 3 When the detection circuit 1) detects that the second switch KA2 is closed, it determines that the HSCB is closed. When the traction control unit detects that the second switch KA2 is open through the first detection circuit, it determines that the HSCB is open.

[0150] For example, the first detection circuit includes a circuit consisting of a first detection terminal of the traction control unit, a first terminal of the second switch KA2, a second terminal of the second switch KA2, and a second detection terminal of the traction control unit. The first detection terminal of the traction control unit is connected to the first terminal of the second switch KA2, and the second terminal of the second switch KA2 is connected to the second detection terminal of the traction control unit. When the second switch KA2 is closed, the first detection circuit is activated, and the traction control unit passes through the first detection circuit (i.e., Figure 3 The detection circuit 1 shown is activated when the second switch KA2 is closed. When the second switch KA2 is deactivated, the first detection circuit is deactivated, and the traction control unit detects the deactivation of the second switch KA2 by detecting the deactivation of the first detection circuit.

[0151] Optional, such as Figure 3 As shown, Figure 3The detection circuit includes a detection switch KT and a first diode D1; the first end of the detection switch KT is connected to the input terminal P1 of the traction control unit, the second end of the detection switch KT is connected to the first terminal of the first leakage current protection device (i.e., the second end of the detection switch KT is connected to the first terminal of the grounding switch QS), the anode of the first diode D1 is connected to the first output terminal P2 of the traction control unit, and the cathode of the first diode D1 is connected to the second terminal of the first leakage current protection device (i.e., the cathode of the first diode D1 is connected to the anode of the second diode D2).

[0152] In this embodiment, the detection switch KT closes when detecting whether the first leakage protection device has failed, and opens when the failure or non-failure of the first leakage protection device is detected. This avoids the impact of high voltage on the traction control unit. The first diode D1 can prevent high voltage from the vehicle body from flowing back to the traction control unit in the event of vehicle leakage, thereby protecting the traction control unit.

[0153] based on Figures 1 to 3 This application provides a leakage current protection method for any type of leakage current protection system. Please refer to... Figure 4 , Figure 4 This is a flowchart illustrating a leakage current protection method provided in an embodiment of this application. Figure 4 As shown, the leakage current protection method may include the following steps.

[0154] 401, The electronic device acquires the electrical signal between the two ends of the first leakage protection device.

[0155] The electronic device can acquire the electrical signal between the two ends of the first leakage current protection device through a detection device. For example, the detection device may include a voltage sensor (such as...). Figure 2 The HV shown is, for example, a voltage Hall sensor. Exemplarily, the detection device could be... Figure 3 The detection circuit shown.

[0156] 402. If the first leakage protection device is determined to be faulty based on the electrical signal between the two ends of the first leakage protection device, the electronic device sends a signal to perform leakage protection action.

[0157] The electrical signal between the two ends of the first leakage current protection device may include a voltage signal or a current signal.

[0158] For example, an electronic device can obtain the voltage between the two ends of the first leakage current protection device through a detection device. If the voltage between the two ends of the first leakage current protection device is greater than or equal to a first threshold and the first leakage current protection device does not send a signal to perform leakage current protection action, it is determined that the first leakage current protection device has failed; if the voltage between the two ends of the first leakage current protection device is less than the first threshold, it is determined that the first leakage current protection device has not failed.

[0159] The signal issued by the first leakage current protection device to activate the leakage current protection can include any of the following:

[0160] The first leakage current protection device triggers the main circuit switch to open and sends leakage current alarm information to the central control unit.

[0161] The following is combined Figure 2 or Figure 3 This describes the process by which the first leakage current protection device triggers the main circuit switch to disconnect.

[0162] The first leakage current protection device includes a leakage current detection unit (LDU), and an overvoltage protection relay included in the LDU is connected in parallel across the leakage current detection resistor GR. The overvoltage protection relay includes a third switch KA3 and a fourth switch KA4. If the leakage voltage U across the leakage current detection resistor GR is greater than a set value, the overvoltage protection relay activates, triggering the third switch KA3 to open, thereby controlling the main circuit switch to disconnect.

[0163] The first leakage current protection device failed to send a signal to perform leakage current protection action, which could be due to the first leakage current protection device failing to trigger the main circuit switch to open, and the first leakage current protection device failing to send leakage current alarm information to the central control unit.

[0164] For example, an electronic device can obtain the voltage between the two ends of the first leakage current protection device through a detection device. If the duration of the voltage between the two ends of the first leakage current protection device being greater than or equal to a first threshold is greater than a first preset duration, and the first leakage current protection device does not output a leakage current protection signal, it is determined that the first leakage current protection device has failed. If the duration of the voltage between the two ends of the first leakage current protection device being greater than or equal to the first threshold is less than the first preset duration, it is determined that the first leakage current protection device has not failed.

[0165] The first leakage current protection device failed to output a leakage current protection signal, which could be due to the first leakage current protection device failing to trigger the main circuit switch to open, or the first leakage current protection device failing to send leakage current alarm information to the central control unit.

[0166] Optionally, the failure of the first leakage current protection device includes at least one of the following:

[0167] The signal for the first leakage current protection device to perform leakage current protection action;

[0168] The first leakage protection device is in the off state.

[0169] The first leakage current protection device does not send a signal to perform leakage current protection action, which means that when the voltage between the two ends of the first leakage current protection device is greater than or equal to the first threshold for a duration longer than the first preset duration, the first leakage current protection device does not output a leakage current protection signal.

[0170] The first residual current device (RCD) being in the open state means that the two ends of the first RCD are disconnected. This could be due to factors such as a damaged leakage detection resistor GR, a damaged second diode D2, or an unclosed grounding switch QS. When the first RCD is in the open state, it cannot perform its leakage protection action.

[0171] Optionally, the electronic device sends a signal to perform a leakage current protection action, including:

[0172] The electronic device sends a signal to control the main circuit switch to open; and / or,

[0173] The electronic device sends a signal to prohibit the first voltage from being applied to the vehicle.

[0174] In this embodiment, the electronic device sends a signal to control the main circuit switch to disconnect, thereby preventing the vehicle from receiving high-voltage power. The electronic device also sends a signal to prevent the vehicle from receiving a first voltage; this prevents high-voltage power from entering the vehicle when the first leakage protection device fails, thus avoiding safety risks.

[0175] The first voltage on the vehicle refers to the high-voltage power supply applied to the vehicle. Applying high-voltage power means energizing the modules within the vehicle that require high-voltage power. Generally, the first voltage is above 100V. Modules requiring high-voltage power can include: traction inverters, auxiliary converters, air conditioning units, etc.

[0176] Optionally, the electronic device may determine the failure of the first leakage current protection device based on the electrical signal between the two ends of the first leakage current protection device, which may include:

[0177] The electronic device determines that the first leakage current protection device has failed based on the voltage between the two ends of the first leakage current protection device and the state of the main circuit switch.

[0178] Specifically, if the voltage across the first residual current device (RCD) is greater than or equal to a first threshold for a duration greater than a first preset duration, and the main circuit switch is closed, the RCD is considered to have failed. If the voltage across the first RCD is greater than or equal to the first threshold for a duration greater than the first preset duration, and the main circuit switch is open, the RCD is considered to have not failed. If the voltage across the first RCD is greater than or equal to the first threshold for a duration less than the first preset duration, the RCD is considered to have not failed.

[0179] The leakage current protection action includes at least one of the following: issuing a signal to control the main circuit switch to disconnect, sending an alarm message of a first leakage current protection device failure to the central processing unit, and sending a leakage current alarm message to the central processing unit.

[0180] In this embodiment of the application, after the failure of the first leakage protection device is detected, leakage protection action can be performed, thereby reducing the risk of electric shock to the vehicle.

[0181] In this embodiment, the failure of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device. In the event of the failure of the first leakage protection device, a signal to perform leakage protection action is issued. The leakage protection action can still be performed even when the first leakage protection device fails, thereby reducing the risk of leakage in the vehicle and improving the safety and reliability of leakage protection.

[0182] based on Figures 1 to 3 This application provides a leakage current protection method for any type of leakage current protection system. Please refer to... Figure 5 , Figure 5 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application. Figure 5 As shown, the leakage current protection method may include the following steps.

[0183] 501, The electronic device acquires the electrical signal between the two ends of the first leakage protection device.

[0184] The specific implementation of step 501 can be found in step 401 above, and will not be repeated here.

[0185] 502. The electronic device determines whether the first leakage current protection device has failed based on the electrical signal between the two ends of the first leakage current protection device.

[0186] The specific implementation of step 502 can be found in step 402 above, and will not be repeated here.

[0187] 503. In the event of failure of the first leakage current protection device, the electronic equipment sends an alarm message about the failure of the first leakage current protection device to the central control unit.

[0188] When the electronic equipment detects a failure of the first leakage current protection device, it sends an alarm message indicating a malfunction of the first leakage current protection device to the central control unit, notifying the central control unit that a leakage current has occurred in the vehicle. This embodiment of the application can promptly notify the central control unit of the leakage current alarm message, allowing the central control unit to quickly learn that a leakage current has occurred in the vehicle, and thus promptly arrange for maintenance personnel to repair the first leakage current protection device and resolve the leakage current fault. Upon receiving the alarm message indicating a malfunction of the first leakage current protection device, the central control unit will not send a high-voltage power-on command to the electronic equipment.

[0189] Optionally, after performing step 502, step 504 or step 505 may also be performed.

[0190] 504. If the first leakage protection device has not failed, the electronic device sends feedback information that the first leakage protection device is normal to the central control unit.

[0191] 505. In the event of failure of the first leakage protection device, the electronic equipment performs leakage protection action.

[0192] The leakage current protection action includes at least one of the following: issuing a signal to control the main circuit switch to disconnect, sending an alarm message of a first leakage current protection device failure to the central processing unit, and sending a leakage current alarm message to the central processing unit.

[0193] In this embodiment of the application, after the failure of the first leakage protection device is detected, leakage protection action can be performed, thereby reducing the risk of electric shock to the vehicle.

[0194] In this embodiment, the electronic device determines that the first leakage protection device has not failed and sends feedback information that the first leakage protection device is normal to the central control unit. After receiving the feedback information that the first leakage protection device is normal, the central control unit can send a high-voltage power-on command to the electronic device.

[0195] based on Figure 2 In addition to the existing leakage current protection system, this application provides another leakage current protection method. Please refer to... Figure 6 , Figure 6 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application. Figure 6 As shown, the leakage current protection method may include the following steps.

[0196] 601, The electronic device acquires the electrical signal between the two ends of the first leakage protection device.

[0197] The specific implementation of step 601 can be found in step 401 above, and will not be repeated here.

[0198] 602. When the voltage between the two ends of the first leakage current protection device is greater than or equal to the first threshold for a duration longer than the first preset duration, and the main circuit switch is in the closed state, the electronic device determines that the first leakage current protection device has failed.

[0199] In this embodiment, if the voltage between the two ends of the first leakage current protection device is greater than or equal to a first threshold for a duration greater than a first preset duration, and the main circuit switch is closed, the first leakage current protection device is considered to have failed. If the voltage between the two ends of the first leakage current protection device is greater than or equal to the first threshold for a duration greater than the first preset duration, and the main circuit switch is open, the first leakage current protection device is considered to have not failed. If the voltage between the two ends of the first leakage current protection device is greater than or equal to the first threshold for a duration less than the first preset duration, and the main circuit switch is closed, the first leakage current protection device is considered to have not failed. If the voltage between the two ends of the first leakage current protection device is greater than or equal to the first threshold for a duration less than the first preset duration, and the main circuit switch is open, the first leakage current protection device is considered to have not failed.

[0200] The electronic device can collect the voltage between the two ends of the first leakage protection device via a voltage sensor. The two ends of the first leakage protection device are connected to the vehicle's high-voltage negative terminal and the vehicle body ground, respectively. When a leakage occurs in the vehicle, the electrical insulation between the vehicle's high-voltage positive terminal and the vehicle body (i.e., the vehicle body ground) fails or short-circuits, resulting in a leakage phenomenon and causing the vehicle body to become energized. At this time, the vehicle body and the vehicle's high-voltage positive terminal have the same potential, while a voltage difference is generated between the vehicle body and the vehicle's high-voltage negative terminal. If a person touches the vehicle body, they will experience an electric shock.

[0201] The first threshold can be preset and stored in the memory of the electronic device (e.g., non-volatile memory). The first preset duration can also be preset and stored in the memory of the electronic device (e.g., non-volatile memory).

[0202] In this embodiment, if the voltage between the two ends of the first leakage current protection device is greater than or equal to a first threshold for a duration longer than a first preset duration, and the main circuit switch is closed, then the first leakage current protection device is considered to have failed. When the first leakage current protection device fails, a voltage sensor can also be used to promptly determine whether leakage has occurred and control the main circuit switch to open, thereby reducing the risk of electric shock to the vehicle. Since the voltage between the vehicle's high-voltage negative terminal and the vehicle body ground may be subject to short-term voltage fluctuations, setting a first preset duration can prevent false judgments of first leakage current protection device failure due to short-term voltage fluctuations.

[0203] Optionally, after performing step 602, step 603 can also be performed.

[0204] 603. In the event of failure of the first leakage protection device, the electronic equipment performs leakage protection action.

[0205] The leakage current protection action includes: issuing a signal to control the main circuit switch to disconnect.

[0206] In this embodiment of the application, after the failure of the first leakage protection device is detected, leakage protection action can be performed, thereby reducing the risk of electric shock to the vehicle.

[0207] Optionally, after performing step 602, step 604 can be performed.

[0208] 604. In the event of failure of the first leakage protection device, the electronic equipment sends leakage alarm information to the central control unit.

[0209] In this embodiment of the application, when the duration of the current leakage between the two ends of the first leakage protection device is greater than or equal to the first threshold and is greater than the first preset duration, it is determined that the vehicle has a current leakage, and the electronic device can send a current leakage alarm message to the central control unit.

[0210] in, Figure 6 The leakage current protection method can be implemented when the vehicle is powered on at high voltage.

[0211] This application embodiment can promptly notify the central control unit of leakage alarm information, allowing the central control unit to quickly learn that the vehicle has a leakage problem, and thus promptly arrange maintenance personnel to repair the first leakage protection device and resolve the vehicle leakage fault.

[0212] based on Figure 2 In addition to the existing leakage current protection system, this application provides another leakage current protection method. Please refer to... Figure 7 , Figure 7 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application. Figure 7 As shown, the leakage current protection method may include the following steps.

[0213] 701, The electronic device acquires the electrical signal between the two ends of the first leakage protection device.

[0214] The specific implementation of step 701 can be found in step 401 above, and will not be repeated here.

[0215] 702. When the voltage between the two ends of the first leakage protection device is greater than or equal to the first threshold, the electronic device detects the state of the main circuit switch.

[0216] The electronic device can collect the voltage between the two ends of the first leakage current protection device through a voltage sensor. The two ends of the first leakage current protection device are connected to the vehicle's high-voltage negative terminal and the vehicle body ground, respectively.

[0217] 703. If the main circuit switch is not disconnected within the first preset time period, the electronic equipment determines that the first leakage protection device has failed.

[0218] In this embodiment, when the first leakage current protection device is working normally, it will passively shut off the main circuit switch when it detects a leakage current in the vehicle (i.e., the voltage difference between the vehicle body ground and the vehicle's high-voltage negative terminal is greater than a first threshold). The first leakage current protection device requires a certain response time from detecting a vehicle leakage current to passively shutting off the main circuit switch. A first preset time longer than this response time can be set (for example, if the response time is generally within 100ms, the first preset time can be set to 100ms). If the duration for which the detected voltage difference between the vehicle body ground and the vehicle's high-voltage negative terminal is greater than or equal to the first threshold is greater than the first preset time, and the main circuit switch is closed, it indicates that the first leakage current protection device has failed. At this time, the electronic device determines that the first leakage current protection device has failed and sends an alarm message indicating a fault in the first leakage current protection device to the central control unit.

[0219] If the duration of a voltage greater than or equal to a first threshold exceeds a first preset duration, it is determined that the vehicle has a current leakage, and the electronic equipment can send a current leakage alarm message to the central control unit.

[0220] The first preset duration is the duration for which the timing begins when the voltage sensor detects that the voltage between the two ends of the first leakage protection device is greater than or equal to the first threshold.

[0221] This application embodiment can promptly notify the central control unit of leakage alarm information, allowing the central control unit to quickly learn that the vehicle has a leakage problem, and thus promptly arrange maintenance personnel to repair the first leakage protection device and resolve the vehicle leakage fault.

[0222] Step 703 is executed after step 702.

[0223] 704. If the main circuit switch is disconnected within a first preset time period, the electronic equipment determines that the first leakage protection device has not failed.

[0224] In this embodiment, timing begins when the voltage sensor detects that the voltage between the vehicle's high-voltage negative terminal and the vehicle's ground is greater than or equal to a first threshold, and the status of the main circuit switch is checked. If the main circuit switch is disconnected within a first preset time period, it indicates that the first leakage protection device has not failed.

[0225] Step 704 is executed after step 702.

[0226] After performing step 703, step 705 can also be performed.

[0227] 705. In the event of failure of the first leakage protection device, the electronic equipment performs leakage protection action.

[0228] The specific implementation of step 705 can be found in step 505 above, and will not be repeated here.

[0229] in, Figure 7 The leakage current protection method can be implemented when the vehicle is powered on at high voltage.

[0230] This application provides a reliable method for determining whether a first leakage current protection device has failed. Specifically, if the main circuit switch is opened within a first preset time period, it indicates that the first leakage current protection device has performed leakage protection action and has not failed. If the voltage between the two ends of the first leakage current protection device, as collected by the voltage sensor, is greater than or equal to a first threshold for a duration longer than the first preset time period, and the main circuit switch is not opened within the first preset time period, it indicates that the first leakage current protection device has failed.

[0231] in, Figure 6 and Figure 7 It can be applied to leakage protection when the vehicle is already energized with high voltage.

[0232] based on Figure 3 In addition to the existing leakage current protection system, this application provides another leakage current protection method. Please refer to... Figure 8 , Figure 8 This is a flowchart illustrating another leakage current protection method provided in an embodiment of this application. Figure 8 As shown, the leakage current protection method may include the following steps.

[0233] 801, Under the condition of the second voltage on the vehicle, the electronic device acquires the electrical signal between the two ends of the first leakage protection device, and determines the on / off state of the first leakage protection device based on the electrical signal between the two ends of the first leakage protection device, wherein the second voltage is less than the first voltage.

[0234] In step 801, when the vehicle is powered on at low voltage, the vehicle is not powered on at high voltage.

[0235] The second voltage on a vehicle refers to the low-voltage power supply. Low-voltage power supply means that modules within the vehicle that require low-voltage power are powered on. Generally, the second voltage is between 3V and 20V. Modules requiring low-voltage power supply may include: the traction control unit.

[0236] Optionally, in step 801, when the vehicle is powered on at low voltage, the electronic device acquires the electrical signal between the two ends of the first leakage current protection device, and determines the on / off state of the first leakage current protection device based on the electrical signal between the two ends of the first leakage current protection device. Specifically, this may include the following steps:

[0237] When the vehicle is powered on at low voltage and the main circuit switch is off, the electronic equipment acquires the electrical signal between the two ends of the first leakage current protection device and determines the on / off state of the first leakage current protection device based on the electrical signal between the two ends of the first leakage current protection device.

[0238] 802, The electronic device determines whether the first leakage protection device has failed based on the on / off status of the first leakage protection device.

[0239] Optionally, the electronic device determines the on / off state of the first leakage current protection device based on the electrical signal between the two ends of the first leakage current protection device, which may specifically include the following steps:

[0240] (11) When an electrical signal is received at one end of the first leakage current protection device and an electrical signal is output at the other end of the first leakage current protection device, the electronic device determines that the first leakage current protection device is in the conducting state.

[0241] (12) When an electrical signal is received at one end of the first leakage current protection device and no electrical signal is output at the other end of the first leakage current protection device, the electronic device determines that the first leakage current protection device is in the off state.

[0242] Optionally, the electronic device determines whether the first leakage current protection device has failed based on its on / off state, which may specifically include the following steps:

[0243] (21) When the first leakage protection device is in the conducting state, it is determined that the first leakage protection device has not failed;

[0244] (22) When the first leakage protection device is in the open state, it is determined that the first leakage protection device is faulty.

[0245] In this embodiment of the application, when the first leakage current protection device is working normally, applying a voltage between the second terminal and the first terminal of the first leakage current protection device enables the first and second terminals of the first leakage current protection device to conduct. When the first leakage current protection device fails, even if a voltage is applied between the second terminal and the first terminal of the first leakage current protection device, the first and second terminals of the first leakage current protection device cannot conduct.

[0246] Electronic devices Figure 3Taking the traction control unit of a leakage current protection system as an example, the electronic device determines the on / off state of the first leakage current protection device. Specifically, the first output terminal P2 of the traction control unit sends a detection signal, and the signal received by the input terminal P1 of the control unit determines whether the first leakage current protection device has failed. Specifically, if the signal received by the input terminal P1 of the control unit is a high-level signal, it is determined that the first leakage current protection device is in a conducting state, i.e., the first leakage current protection device has not failed; if the signal received by the input terminal P1 of the control unit is a low-level signal, it is determined that the first leakage current protection device is in a disconnected state, i.e., the first leakage current protection device has failed.

[0247] The detection signal can be a voltage signal (such as a voltage pulse signal). A high-level signal can be a signal with a voltage greater than a set threshold, and a low-level signal can be a signal with a voltage less than a set threshold. For example, the voltage signal can be a 5V signal, and the set threshold can be set to 3V.

[0248] Optionally, after performing step 802, step 803 or step 804 can be performed.

[0249] 803. In the event of failure of the first leakage protection device, the electronic equipment performs leakage protection action.

[0250] The leakage protection action includes preventing the vehicle from receiving high-voltage power. For example, the electronic device can send a signal to prevent the vehicle from receiving a first voltage, thereby preventing the vehicle from receiving high-voltage power.

[0251] In this embodiment of the application, after the failure of the first leakage protection device is detected, leakage protection action can be performed, thereby reducing the risk of electric shock to the vehicle.

[0252] 804. If the first leakage protection device does not fail, the electronic equipment allows the vehicle to be powered on at high voltage.

[0253] For example, an electronic device may emit a signal that allows a first voltage to be applied to the vehicle, thereby allowing the vehicle to be powered on at high voltage.

[0254] Optionally, after performing step 804, step 805 can also be performed.

[0255] 805, when the vehicle is allowed to apply a first voltage and an instruction to apply the first voltage is received, the electronic device sends a signal to control the closing of the main circuit switch; wherein, the first leakage protection device is used to detect whether the vehicle is leaking current when the main circuit switch is closed, and to trigger the main circuit switch to open when leakage current is detected.

[0256] In this embodiment, when the vehicle is allowed to be powered on at high voltage, if a high voltage power-on command (controlling the main circuit switch to close) is received, a signal is sent to the main circuit switch to control its closure, thereby enabling the vehicle to be powered on at high voltage. This ensures that the first leakage protection device can function normally and perform leakage protection after the vehicle is powered on at high voltage, thus reducing the risk of electric shock.

[0257] Optionally, after performing step 803, step 806 can also be performed.

[0258] 806, when the first voltage is prohibited on the vehicle, the electronic device restarts the first leakage protection device and re-determines whether the first leakage protection device has failed based on the electrical signal between the two ends of the first leakage protection device.

[0259] In this embodiment, after detecting a failure of the first leakage current protection device and prohibiting the vehicle from receiving high-voltage power, the first leakage current protection device can be restarted. The fault of the first leakage current protection device can be eliminated by restarting it after its failure is detected.

[0260] In this embodiment, after re-detecting whether the first leakage protection device has failed, if the first leakage protection device has not failed, the electronic device allows the vehicle to be powered on at high voltage and sends feedback information indicating that the first leakage protection device is functioning normally to the central control unit. If the first leakage protection device still fails, the electronic device still prohibits the vehicle from being powered on at high voltage.

[0261] In this embodiment, after detecting a failure of the first leakage current protection device and prohibiting the vehicle from receiving high voltage, the first leakage current protection device can be restarted. Restarting the first leakage current protection device can eliminate its fault. This embodiment allows the first leakage current protection device to be restored to normal operation as quickly as possible, enabling the vehicle to receive high voltage and resume normal operation quickly.

[0262] in, Figure 8 It can be applied to leakage protection of vehicles before high voltage is applied.

[0263] based on Figure 2 The leakage current protection system shown in this application provides a leakage current protection method. Please refer to [link to relevant documentation]. Figure 9 , Figure 9 This is a schematic diagram illustrating the specific process of a leakage current protection method provided in an embodiment of this application. Figure 9 As shown, the leakage current protection method may include the following steps.

[0264] 901, The vehicle is experiencing an electrical leakage problem.

[0265] 902, the leakage voltage U across the leakage detection resistor GR is detected by the first leakage protection device.

[0266] Step 902 is executed after step 901.

[0267] 903. When U is greater than the first preset voltage U1, it is determined that leakage has occurred at the positive terminal of the vehicle.

[0268] The first preset voltage U1 can be the first threshold mentioned above.

[0269] 904, the first leakage protection device triggers the disconnection of HSCB to perform the vehicle's own leakage protection action and outputs a leakage alarm signal.

[0270] Steps 902 to 904 constitute the first layer of leakage protection.

[0271] 905, the voltage U between the vehicle's high-voltage negative terminal and the vehicle body ground is collected by the voltage sensor HV, and the voltage U is detected by the traction control unit.

[0272] Step 905 is executed after step 901.

[0273] 906. When U is greater than the first preset voltage U1, it is determined that there is leakage at the positive terminal of the vehicle. The traction control unit determines the status of HSCB by detecting the status of the second switch KA2.

[0274] 907. Determine whether the HSCB has disconnected within the first preset time t1. If yes, proceed to step 908; otherwise, proceed to step 909.

[0275] The first preset duration is the duration from the time the voltage U is detected to be greater than the first preset voltage U1.

[0276] 908, the traction control unit determines that the leakage protection has been activated and sends an additional disconnect command to the first switch KA1 to control the HSCB to disconnect, ensuring that the HSCB is reliably disconnected.

[0277] 909. If the duration t of U being greater than the first preset voltage U1 exceeds the first preset time t1, the traction control unit controls the HSCB to disconnect for leakage protection and simultaneously outputs leakage alarm information to the CCU.

[0278] After performing step 909, you can proceed to step 910.

[0279] 910, the traction control unit determines that the first leakage protection device is faulty and outputs a leakage protection device fault alarm to the CCU.

[0280] Steps 905 to 910 constitute the second layer of leakage protection.

[0281] After performing step 904, step 908, or step 910, step 911 can be performed.

[0282] 911, the second leakage protection device determines whether leakage can be detected at the positive terminal of the power grid when the leakage occurs and the second preset time t2.

[0283] After performing step 911, proceed to step 912.

[0284] 912. If the second leakage protection device still detects leakage at the positive terminal of the power grid, it controls the corresponding power supply line of the vehicle to trip in order to perform line leakage protection action.

[0285] Steps 911 to 912 constitute the third layer of leakage protection.

[0286] In this embodiment, a voltage sensor connected between the vehicle's high-voltage negative terminal and the vehicle's ground collects the leakage voltage U between the vehicle's high-voltage negative terminal and the vehicle's ground in real time, and this is detected by the traction control unit. If a component of the first leakage protection device fails, such as a damaged leakage detection resistor GR, a damaged second diode D2, or a grounding switch QS not being closed, causing the overvoltage protection relay to fail to operate accordingly, and thus failing to promptly disconnect the HSCB to achieve leakage protection, or trigger a leakage alarm signal through the fourth switch KA4, resulting in the vehicle body being in a live state, the traction control unit will trigger the leakage protection action. The specific process is as follows:

[0287] The traction control unit detects the voltage U collected by the voltage sensor HV.

[0288] If U > the first preset voltage U1, the traction control unit determines that the leakage voltage judgment condition is met, and then the traction control unit judges the status of HSCB through the second switch KA2.

[0289] If the HSCB disconnects within the first preset time t1, the traction control unit determines that the leakage protection action has been triggered, and the traction control unit adds a disconnect command to the first switch KA1 to ensure that the high-voltage main circuit is completely disconnected.

[0290] If the duration t of U > U1 exceeds the first preset duration t1, and the traction control unit detects that the HSCB is not disconnected through the second switch KA2, the traction control unit outputs a disconnect command to the first switch KA1 to control the disconnection of the HSCB for leakage protection, and the traction control unit simultaneously outputs leakage alarm information to the CCU.

[0291] At the same time, the traction control unit determines that the first leakage protection device is faulty and cannot detect leakage, and outputs a leakage protection device fault alarm to the CCU.

[0292] If the duration t of U > U1 is not greater than t1, and the leakage protection action of the first leakage protection device is not triggered, i.e., the HSCB is not disconnected, then the traction control unit will not perform the leakage protection action.

[0293] The distribution cabinet (e.g., the distribution cabinet in the traction substation) is equipped with a corresponding second leakage protection device. The second leakage protection device is used to control the power supply line corresponding to the vehicle to trip when leakage is detected at the positive terminal of the power grid after the leakage time reaches the second preset time t2.

[0294] The first preset duration t1, the second preset duration t2, and the first preset voltage U1 can be calibrated according to actual conditions. For example, in some applications, t1 = 200ms, t2 = 400ms, and U1 = 100V.

[0295] This application embodiment provides multiple layers of protection against vehicle leakage. Firstly, a first leakage protection device provides the first layer of protection. If the first leakage protection device fails, the traction control unit detects the voltage between the vehicle's high-voltage negative terminal and the vehicle body ground to provide the second layer of protection. If the traction control unit performs leakage protection but the second leakage protection device in the distribution cabinet still detects leakage, then the second leakage protection device provides the third layer of protection. This application embodiment, through three layers of leakage protection, effectively reduces the risk of leakage in the vehicle and its power supply system.

[0296] In this embodiment, a voltage sensor HV is added between the vehicle's high-voltage negative terminal and the vehicle body ground. This voltage sensor detects the voltage difference between the vehicle's high-voltage negative terminal and the vehicle body ground. The voltage information is collected by the traction control unit. When a leakage occurs in the vehicle, if the first leakage protection device fails to perform its protective action, the traction control unit can determine whether a leakage fault has occurred based on the voltage difference collected by the voltage sensor. If a leakage is detected, the traction control unit actively controls the disconnection of the main circuit switch HSCB and simultaneously outputs a leakage fault alarm. This combines passive and active leakage protection, resulting in higher reliability of the leakage protection system.

[0297] In this embodiment, leakage protection is prioritized through the passive protection action of the first leakage protection device when leakage occurs. If the first leakage protection device malfunctions and fails to activate, the traction control unit detects the leakage and actively initiates leakage protection. Furthermore, to avoid affecting the normal operation of other vehicles, if leakage still exists after a period of time following the activation of the leakage protection device, a second leakage protection device is activated to provide line leakage protection, thus preventing safety accidents.

[0298] based on Figure 3The leakage current protection system shown in this application provides a leakage current protection method. Please refer to [link to relevant documentation]. Figure 10 , Figure 10 This is a schematic diagram illustrating the specific process of another leakage current protection method provided in the embodiments of this application. Figure 10 As shown, the leakage current protection method may include the following steps.

[0299] 1001, Vehicle low voltage power-on.

[0300] After executing step 1001, execute step 1002.

[0301] 1002, the traction control unit controls the disconnection of HSCB and the closure of KT to perform status detection on the first leakage protection device.

[0302] After performing step 1002, proceed to step 1003.

[0303] 1003. Determine if the first leakage protection device is functioning properly; if yes, proceed to step 1004; if no, proceed to step 1005.

[0304] 1004, the traction control unit feeds back the normal detection result to the CCU, controls the disconnection of KT, and waits for the high voltage power-on command.

[0305] After executing step 1004, execute step 1008.

[0306] 1005, the traction control unit feeds back the fault information of the first leakage protection device to the CCU, and at the same time controls the disconnection of KT.

[0307] After executing step 1005, execute step 1006.

[0308] 1006, the traction control unit no longer responds to the high-voltage power-on request and controls the first switch KA1 to open.

[0309] After executing step 1006, execute step 1007.

[0310] 1007. After the first leakage protection device restarts, determine whether the first leakage protection device is normal; if yes, proceed to step 1008; if no, proceed to step 1009.

[0311] 1008. High voltage power-on is permitted. When the high voltage power-on command is received and the traction control unit passes the self-test, the traction control unit controls the first switch KA1 to close.

[0312] After executing step 1008, execute step 1010.

[0313] 1009. The traction control unit is not allowed to be powered by high voltage.

[0314] 1010, the first leakage protection device detects the leakage voltage across the leakage detection resistor. If the leakage voltage U is greater than the set value, it is determined to be a leakage.

[0315] After performing step 1010, proceed to step 1011.

[0316] 1011, in the event of a leakage current, the HSCB is triggered to disconnect for leakage current protection.

[0317] After performing step 1011, proceed to step 1012.

[0318] 1012, When the second leakage protection device determines that leakage has occurred for a preset time, it detects whether there is leakage at the positive terminal of the power grid.

[0319] After performing step 1012, proceed to step 1013.

[0320] 1013. If the second leakage protection device still detects leakage at the positive terminal of the power grid, it controls the corresponding power supply line of the vehicle to trip in order to perform line leakage protection action.

[0321] In the embodiments of this application, such as Figure 3 As shown, the vehicle draws power from the positive and negative terminals of the power grid via positive and negative current drawers. The positive and negative terminals of the power grid are connected to a distribution box. A high-voltage current collector (HSCB) is installed between the vehicle's high-voltage positive terminal and the power grid's positive terminal. The distribution box contains a first leakage current protection device and a detection circuit. The first leakage current protection device consists of: a grounding switch QS, a leakage current detection resistor GR, a second diode D2, and a leakage current detection unit LDU. The detection circuit includes: a detection switch KT and a first diode D1. The control circuit of the HSCB includes: a first switch KA1 for protection in case of leakage, and the first switch KA1 in the HSCB control circuit.

[0322] If the electrical insulation between the vehicle's high-voltage positive terminal and the vehicle body (i.e., the vehicle body ground) fails or short-circuits, a leakage current will occur, causing the vehicle body to become energized. At this time, the vehicle body ground and the vehicle's high-voltage positive terminal are at the same potential, and a voltage difference is generated between the vehicle body ground and the vehicle's high-voltage negative terminal. The first leakage protection device determines whether a leakage current has occurred based on this voltage difference.

[0323] The first leakage current protection device is connected between the vehicle body ground and the vehicle's high-voltage negative terminal. This device includes a leakage detection resistor GR connected in series between the vehicle body ground and the vehicle's high-voltage negative terminal, a grounding switch QS, a second diode D2, and a leakage detection unit LDU. The grounding switch QS is normally closed and is only manually opened during vehicle insulation testing or other maintenance work to avoid affecting the maintenance results. The second diode D2 blocks the connection between the vehicle's high-voltage negative terminal and the vehicle body ground. The leakage detection unit LDU detects the voltage across the leakage detection resistor GR and determines that leakage has occurred at the vehicle's high-voltage positive terminal when the voltage across GR exceeds a set value, triggering the leakage current protection action.

[0324] The specific implementation process of the leakage current protection is as follows: The overvoltage protection relay included in the leakage current detection unit (LDU) is connected in parallel across the leakage current detection resistor GR. The overvoltage protection relay includes a third switch KA3 and a fourth switch KA4. If the voltage across the leakage current detection resistor GR is greater than a set value, the overvoltage protection relay activates, the third switch KA3 opens, causing the control circuit of the main circuit switch to disconnect, thereby controlling the main circuit switch to open. Simultaneously, it triggers the fourth switch KA4 to close. After the traction control unit detects the closing signal of the fourth switch KA4 through detection circuit 2, it determines that the vehicle has a leakage current and outputs a leakage current alarm message to the central control unit.

[0325] The detection circuit is controlled and signals are acquired by the traction control unit. The detection circuit is connected between the vehicle's high-voltage negative terminal and the vehicle's ground. The detection switch KT remains open; when testing the on-board leakage protection device is required, the traction control unit closes KT. The first diode D1 blocks the connection between the traction control unit and the vehicle's ground, preventing damage to the traction control unit from the high-voltage power supply in the event of a leakage. P1 and P2 are the input and first output terminals of the traction control unit, respectively.

[0326] After the vehicle is powered on at low voltage, the traction control unit performs the following self-test: The traction control unit outputs a disconnect command to the first switch KA1 to disconnect the HSCB, and confirms the on / off status of the HSCB by switching the second switch KA2 on and off; after confirming that the HSCB is disconnected, the traction control unit controls the closing of the detection switch KT; after KT is closed, the traction control unit outputs a detection signal through the first output terminal P2, and collects the status of the first leakage protection device through the input terminal P1.

[0327] If the status of the first leakage current protection device is normal, the traction control unit determines that the first leakage current protection device is normal and feeds back the normal status information of the first leakage current protection device to the CCU. At the same time, it controls the disconnection of the detection switch KT. After KT is disconnected, it waits for the high voltage power-on command. When the high voltage power-on command is received and the traction control unit passes the self-test, it outputs a closing command to the first switch KA1.

[0328] If the status of the first leakage protection device is abnormal, the traction control unit determines that the first leakage protection device is faulty, feeds back the fault information of the first leakage protection device to the CCU, controls the disconnection detection switch KT to no longer respond to the vehicle's high voltage power-on demand, and outputs a disconnection command to the first switch KA1.

[0329] After the vehicle is powered on at high voltage, the first leakage protection device monitors the vehicle's leakage status in real time. The overvoltage protection relay included in the leakage detection unit (LDU) is connected in parallel across the leakage detection resistor GR. The overvoltage protection relay includes a third switch KA3 and a fourth switch KA4. If the leakage voltage U across the leakage detection resistor GR is greater than a set value, the overvoltage protection relay activates, triggering the third switch KA3 to open, thereby controlling the HSCB to disconnect. Simultaneously, it triggers the fourth switch KA4 to close, outputting a leakage alarm signal. After the traction control unit detects the closed signal of the fourth switch KA4, it determines that the vehicle has a leakage and outputs leakage alarm information.

[0330] The distribution cabinet (e.g., the distribution cabinet in the traction substation) is equipped with a corresponding second leakage protection device. The second leakage protection device is used to control the power supply line corresponding to the vehicle to trip in order to perform line leakage protection action when the duration of leakage at the positive terminal of the power grid exceeds a preset duration.

[0331] The preset duration t1 and the set value U1 can be calibrated according to the actual situation. For example, in some application instances, t1 = 400ms and U1 = 100V.

[0332] The embodiments of this application can promptly identify the fault status of the first leakage protection device, preventing the vehicle from operating with a fault and effectively reducing the risk of leakage in the vehicle and its power supply system.

[0333] The leakage current protection system of this application embodiment can realize vehicle leakage current protection function. If leakage current occurs at the positive high voltage terminal of the vehicle, the first leakage current protection device will trigger the leakage current protection action after the leakage current voltage reaches a preset value, controlling the disconnection of the high-speed circuit breaker HSCB to realize vehicle leakage current protection. This leakage current protection system can detect the fault of the first leakage current protection device before high voltage is applied. After each low voltage power-on, the vehicle actively performs a functional test on the first leakage current protection device and determines whether its operation is normal. When it is determined that the vehicle leakage current detection device is working normally, the vehicle is allowed to be powered on at high voltage and run online. Otherwise, the vehicle is not allowed to be powered on at high voltage, and a fault alarm is output to the CCU. Secondly, after the vehicle is powered on at high voltage, the first leakage current protection device will determine the leakage current. When leakage current occurs, the leakage current protection action will be triggered to realize leakage current protection. In order to avoid affecting the normal operation of other vehicles, if leakage current still exists after a period of time after the leakage current protection action, the second leakage current protection device will be used for line leakage current protection to prevent safety accidents.

[0334] The above describes the solutions of the embodiments of this application from the perspective of the method execution process. It is understood that, in order to achieve the above functions, the electronic device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments provided herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0335] This application embodiment can divide the electronic device into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0336] Please see Figure 11 , Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application, such as... Figure 11 As shown, the electronic device 1100 includes a processor 1101 and a memory 1102, which are interconnected via a communication bus 1103. The communication bus 1103 can be a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, or a controller area network (CAN) bus, etc. The communication bus 1103 can be divided into an address bus, a data bus, and a control bus, etc. For ease of illustration, Figure 11 The bus is represented by a single thick line, but this does not indicate that there is only one bus or one type of bus. Memory 1102 stores computer programs, which include program instructions. Processor 1101 is configured to invoke these program instructions, which include instructions for execution. Figures 4 to 10 It includes some or all of the steps in the methods.

[0337] The processor 1101 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the above scheme program.

[0338] The memory 1102 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory may exist independently and be connected to the processor via a bus. The memory may also be integrated with the processor.

[0339] The electronic device 1100 may also include a communication module 1104. The electronic device 1100 can communicate with the CCU through the communication module 1104 and send feedback information of normal operation of the first leakage current protection device, alarm information of fault of the first leakage current protection device, etc. to the CCU through the communication module 1104.

[0340] Electronic devices can be traction control units in leakage protection systems.

[0341] In this embodiment, the failure of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device. If the first leakage protection device fails, a signal to perform leakage protection action is issued. The leakage protection action can still be performed even when the first leakage protection device fails, thereby reducing the risk of leakage in the vehicle and improving the safety and reliability of leakage protection.

[0342] This application also provides a vehicle, including the above-described... Figure 11 The electronic devices in this application. The vehicle in the embodiments of this application can be a rail transit vehicle. For example, a rail transit vehicle can include any one of a subway, urban rail train, monorail, tram, monorail, skybus, and high-speed rail.

[0343] This application also provides a computer-readable storage medium storing a computer program for electronic data interchange that causes a computer to perform some or all of the steps of any of the leakage current protection methods described in the above method embodiments.

[0344] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0345] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0346] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0347] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0348] Furthermore, the functional units in the various embodiments of the application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software program module.

[0349] If the integrated unit is implemented as a software program module and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0350] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage device, which may include: a flash drive, a read-only memory, a random access memory, a magnetic disk, or an optical disk, etc.

[0351] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A leakage current protection method, characterized in that, include: The electrical signal between the two ends of the first leakage current protection device is obtained. If the first leakage current protection device is determined to be faulty based on the electrical signal between the two ends of the first leakage current protection device, a signal to execute the leakage current protection action is issued.

2. The method according to claim 1, characterized in that, The failure of the first leakage current protection device includes at least one of the following: The first leakage protection device did not send a signal to execute leakage protection action; The first leakage protection device is in the off state.

3. The method according to claim 1, characterized in that, The signal to activate the leakage current protection action includes: Send a signal to control the main circuit switch to open; and / or, A signal is issued prohibiting the application of the first voltage to the vehicle.

4. The method according to claim 1, characterized in that, The step of determining the failure of the first leakage current protection device based on the electrical signal between its two ends includes: The failure of the first leakage current protection device is determined based on the voltage between the two ends of the first leakage current protection device and the state of the main circuit switch.

5. The method according to claim 4, characterized in that, The step of determining the failure of the first leakage current protection device based on the voltage between its two ends and the state of the main circuit switch includes: If the voltage between the two ends of the first leakage current protection device is greater than or equal to the first threshold for a duration longer than the first preset duration, and the main circuit switch is in the closed state, the first leakage current protection device is determined to be faulty.

6. The method according to claim 4, characterized in that, The step of determining the failure of the first leakage current protection device based on the voltage between its two ends and the state of the main circuit switch includes: When the voltage between the two ends of the first leakage protection device is greater than or equal to the first threshold, the status of the main circuit switch is detected. If the main circuit switch is not disconnected within a first preset time period, the first leakage protection device is determined to be faulty.

7. The method according to claim 3, characterized in that, The step of determining the failure of the first leakage current protection device based on the electrical signal between its two ends includes: In the case of a second voltage on the vehicle, the on / off state of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device, where the second voltage is less than the first voltage. If the first leakage current protection device is in the off state, it is determined that the first leakage current protection device has failed.

8. The method according to any one of claims 1 to 7, characterized in that, The method further includes: If it is determined that the first leakage protection device has not failed based on the electrical signal between the two ends of the first leakage protection device, a signal is issued to allow the first voltage on the vehicle.

9. The method according to claim 8, characterized in that, The method further includes: When the vehicle is allowed to be supplied with a first voltage and an instruction to supply the first voltage is received, a signal is issued to control the main circuit switch to close; wherein, the first leakage protection device is used to detect whether the vehicle is leaking current when the main circuit switch is closed, and to trigger the main circuit switch to open when the leakage current is detected.

10. The method according to claim 7, characterized in that, Determining the on / off state of the first leakage current protection device based on the electrical signal between its two ends includes: When the main circuit switch is open, the on / off state of the first leakage current protection device is determined based on the electrical signal between the two ends of the first leakage current protection device.

11. The method according to claim 10, characterized in that, Determining the on / off state of the first leakage current protection device based on the electrical signal between its two ends includes: When an electrical signal is received at one end of the first leakage current protection device and an electrical signal is output at the other end of the first leakage current protection device, it is determined that the first leakage current protection device is in a conducting state. If an electrical signal is received at one end of the first leakage current protection device and no electrical signal is output at the other end of the first leakage current protection device, it is determined that the first leakage current protection device is in the off state.

12. The method according to claim 7 or 11, characterized in that, The step of determining the failure of the first leakage current protection device based on its on / off state includes: If the first leakage current protection device is in the off state, it is determined that the first leakage current protection device has failed.

13. The method according to any one of claims 9 to 12, characterized in that, The method further includes: When the first voltage on the vehicle is blocked, the first leakage protection device is restarted, and the failure of the first leakage protection device is determined based on the electrical signal between the two ends of the first leakage protection device.

14. An electronic device, characterized in that, The device includes a processor and a memory, the memory being used to store a computer program, the computer program including program instructions, and the processor being configured to invoke the program instructions to perform the method as described in any one of claims 1 to 13.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described in any one of claims 1 to 13.

16. A computer program product, characterized in that, The computer program product includes a computer program operable to cause a computer to perform the method as described in any one of claims 1 to 13.

17. A vehicle, characterized in that, Including the electronic device as described in claim 14.

18. The vehicle according to claim 17, characterized in that, The vehicle also includes a central control unit, which establishes a communication connection with the electronic equipment; The central control unit is used to receive alarm information from the electronic device indicating that the first leakage current protection device has failed, in the event of failure of the first leakage current protection device.

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