CN111537846A - Vehicle end-of-line insulation testing equipment and testing method for electric vehicles - Google Patents

Abstract

The invention discloses a vehicle off-line insulation detection device for electric vehicles and a detection method thereof. The vehicle off-line insulation detection device includes: an insulation detection interface includes a DC power port, a device ground wire port, and a charging communication port , the charging connection confirmation port and the auxiliary power port, the insulation detection interface is connected to the DC charging interface of the electric vehicle to be detected; the electronic control unit is connected to the charging communication port in the insulation detection interface, and the charging communication port of the electronic control unit is connected to the charging communication port to be detected. The battery management system of the electric vehicle sends instructions; an insulation resistance tester includes an insulating positive electrode and an insulating negative electrode, and the insulating negative electrode is connected to the ground wire port of the device; a selection switch is connected to the DC power port of the insulation detection interface and between the insulation positive poles of the insulation resistance tester. Compared with the prior art, the present invention can conveniently detect the insulation performance of the whole vehicle without additionally disconnecting the high-voltage components.

Description

Vehicle end-of-line insulation testing equipment and testing method for electric vehicles

【Technical field】

The invention relates to the technical field of electric vehicles, in particular to a vehicle off-line insulation detection device for electric vehicles and a detection method thereof.

【Background technique】

Electric vehicles need safety inspections, including the insulation performance of the whole vehicle, when they are in the final inspection line of the vehicle. The insulation performance test needs to measure the insulation resistance of the high-voltage positive circuit to the body and the insulation resistance of the high-voltage negative circuit to the body. When the vehicle is off the assembly line, it is already in a fully assembled state and cannot touch the high-voltage circuit, so the measurement cannot be performed. At present, only the high-voltage components can be disconnected to meet the test conditions. In addition, the power battery system in the electric vehicle has its own insulation detection function, which will affect the equipment test.

Therefore, it is necessary to provide a new technical solution to overcome the above problems.

[Content of the invention]

The technical problem to be solved by the present invention is to provide a vehicle off-line insulation detection device for electric vehicles and a detection method thereof. When the vehicle off-line insulation is detected, it does not require additional disconnection of high-voltage components and can connect the power battery system The built-in insulation detection function is turned off, so that the insulation performance of the whole vehicle can be easily detected.

In order to solve the above problems, according to one aspect of the present invention, the present invention provides a vehicle off-line insulation detection device for electric vehicles, which includes: an insulation detection interface, which is used for connecting with the DC charging interface of the electric vehicle to be detected. connection, the insulation detection interface includes a DC power port, a device ground port, a charging communication port, a charging connection confirmation port and an auxiliary power port, and each port in the insulation detection interface corresponds to each port in the DC charging interface One-to-one docking; electronic control unit, which is connected to the charging communication port in the insulation detection interface, the electronic control unit communicates to the to-be-detected charging communication port through the docking of the DC charging interface and the charging communication port in the insulation detection interface The battery management system of the electric vehicle sends an instruction; an insulation resistance tester includes an insulating positive electrode and an insulating negative electrode, the insulating negative electrode is connected to the ground wire port of the device, and the insulation resistance tester is used to measure the test positive electrode and test The insulation resistance value between the negative poles; a selection switch, which is connected between the DC power supply port of the insulation detection interface and the insulation positive pole of the insulation resistance tester, which is used to control the DC power supply port and the insulation positive pole the connection between.

Further, the instruction includes: closing the main negative switch, main positive switch and fast charging switch connected to the power battery in the electric vehicle to be detected; and/or closing the insulation monitoring circuit of the battery management system.

Further, the DC power port includes a DC power positive port and a DC power negative port; the selection switch is connected to the DC power positive port of the insulation detection interface, the DC power negative port and the test positive electrode of the insulation resistance tester. In between, the selection switch is used to selectively connect the test positive electrode with the positive terminal of the DC power supply or the negative terminal of the DC power supply.

Further, the charging communication port includes a first charging communication port and a second charging communication port; the charging connection confirmation port includes a first charging connection confirmation port and a second charging connection confirmation port; the auxiliary power port includes an auxiliary power supply Positive port and Auxiliary power negative port.

Further, the selection switch is a three-position selection switch. When the selection switch is in the first position, the selection switch interrupts the connection between the DC positive port and the test positive terminal, and interrupts the DC negative port and the test positive terminal. the connection of the test positive electrode; when the selection switch is in the second position, the selection switch connects the DC positive terminal and the test positive terminal, and interrupts the connection between the DC negative terminal and the test positive terminal; when When the selection switch is in the third position, the selection switch interrupts the connection between the DC positive terminal and the test positive terminal, and connects the DC negative terminal and the test positive terminal.

Further, the selection switch is a three-position self-locking rotary switch, and the three-position self-locking rotary switch includes a first sub-switch and a second sub-switch, and the first sub-switch is connected to the positive port of the DC power supply and the between the test positive poles; the second sub-switch is connected between the negative terminal of the DC power supply and the test positive pole; when the selection switch is in the first position, the first sub-switch is turned off and the second sub-switch is turned off Turn off; when the selection switch is in the second position, the first sub-switch is turned on and the second sub-switch is turned off; when the selection switch is in the third position, the first sub-switch is turned off and the second sub-switch is turned off on.

According to another aspect of the present invention, the present invention provides a detection method for an off-line insulation detection device of an electric vehicle, comprising the steps of: connecting an insulation detection interface of the off-line insulation detection device of an electric vehicle with the to-be-detected insulation detection interface. connected to the DC charging interface of the electric vehicle; supply power to the electric vehicle to be detected through the docked DC charging interface and the auxiliary power port in the insulation detection interface to wake up the whole vehicle; after the whole vehicle is woken up, the The electronic control unit sends an instruction to the battery management system of the electric vehicle to be detected via the charging communication port in the connected DC charging interface and the insulation detection interface; after the battery management system executes the instruction, the insulation resistance test is performed by the battery management system. The instrument performs the high-voltage circuit insulation detection of the whole vehicle off the assembly line for the electric vehicle to be detected through the selection switch.

Further, the instruction includes: closing the main negative switch, the main positive switch and the fast charging switch connected to the power battery in the electric vehicle to be detected; and/or closing the insulation monitoring circuit of the battery management system.

Further, the step of "using the insulation resistance tester to perform the high-voltage loop insulation detection of the electric vehicle to be detected through the selection switch when the whole vehicle is off-line" includes: connecting the positive terminal of the DC power supply and the insulation positive terminal. The insulation resistance tester measures the insulation resistance of the high-voltage positive circuit to the vehicle body; the negative terminal of the DC power supply is connected to the insulating negative electrode, and the insulation resistance tester measures the insulation resistance of the high-voltage negative circuit to the vehicle body.

Further, after the insulation detection of the high-voltage circuit of the whole vehicle is completed, the insulation detection data is sent to the local display, and the local display is the manufacturing execution system of the factory or the equipment of the operator.

Compared with the prior art, the vehicle off-line insulation detection device and its detection method for electric vehicles in the present invention perform communication and vehicle off-line insulation detection on the electric vehicle to be detected through the on-board DC charging interface. In this way, the present invention does not need to disconnect the high-voltage components additionally and can turn off the insulation detection function of the power battery system during the insulation detection of the whole vehicle off-line, so that the insulation performance of the whole vehicle can be conveniently detected.

Other objects, features and advantages of the present invention will be described in detail in the detailed description below with reference to the accompanying drawings.

【Description of drawings】

The present invention will be better understood by reference to the accompanying drawings and the following detailed description, wherein like reference numerals correspond to like structural components, wherein:

FIG. 1 is a schematic circuit diagram of the vehicle off-line insulation detection device in an embodiment of the present invention when an electric vehicle to be detected is tested for the off-line insulation of the entire vehicle;

Figure 2 is a diagram of the contact arrangement of the DC fast charging vehicle socket in accordance with GB/T 20234.3-2015; and

FIG. 3 is a flow chart of the detection method of the insulation detection equipment for the end-of-line insulation of the electric vehicle shown in FIG. 1 .

【Detailed ways】

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic associated with the described embodiment may be included in at least one implementation of the present invention. The appearances of "in one embodiment" in various places in this specification are not necessarily all referring to the same embodiment, nor are they necessarily separate or alternative embodiments that are mutually exclusive of other embodiments. In the present invention, "plurality" and "several" mean two or more. "And/or" in the present invention means "and" or "or".

Please refer to FIG. 1 , which is a schematic circuit diagram of the vehicle off-line insulation detection device 200 for detecting the vehicle off-line insulation of the electric vehicle 100 to be detected in one embodiment of the present invention.

In the embodiment shown in FIG. 1 , the vehicle off-line insulation testing device 200 communicates and tests the electric vehicle 100 to be tested via (or utilizes) the on-board DC charging interface 110 , so as to realize the complete vehicle testing of the electric vehicle 100 to be tested. End-of-line insulation detection.

The electric vehicle 100 to be tested is at the vehicle off-line insulation testing station. The electric vehicle 100 to be tested includes a DC charging interface (or fast charging interface) 110 , a power battery 120 , a main positive switch 130 , a main negative switch 140 , a fast charging switch 150 and a high voltage box 160 .

The DC charging interface 110 includes a DC power supply positive port DC+, a DC power supply negative port DC-, a device ground port PE, a first charging communication port S+, a second charging communication port S-, a first charging connection confirmation port CC1, and a first charging connection confirmation port CC1. Two charging connection confirmation port CC2, low voltage auxiliary power positive terminal A+ and low voltage auxiliary power negative terminal A-. The DC charging interface 110 usually adopts a DC fast charging vehicle socket in accordance with the provisions of GB/T20234.3-2015, as shown in FIG. 2 for details.

The main positive switch 130 is connected between the positive terminal of the power battery 120 and the main positive terminal of the high voltage box 160 ; the main negative switch 140 is connected to the negative terminal of the power battery 120 and the high voltage box 160 . between the main and negative terminals; the fast charging switch 150 is connected between the positive terminal of the power battery 120 and the positive terminal DC+ of the DC power supply of the DC charging interface 110 . In the specific embodiment shown in FIG. 1 , the main positive switch 130 , the main negative switch 140 and the fast charging switch 150 are all relays, that is, the main positive switch 130 is the main positive relay, and the main negative switch 140 is the main negative The relay, the fast charging switch 150 is a fast charging relay.

The vehicle off-line insulation detection device 200 includes an insulation detection interface 210 , an auxiliary power supply 220 , an electronic control unit ECU 230 , an insulation resistance tester 240 and a selection switch 250 .

The insulation detection interface 210 is used for connecting (or docking or pluggable docking) with the DC charging interface 100 of the electric vehicle 100 to be detected, and each port in the insulation detection interface 210 is connected to the DC charging interface 100 Each port in the corresponding settings. That is to say, the insulation detection interface 210 also includes a positive DC power port DC+, a DC power negative port DC-, a device ground port PE, a first charging communication port S+, a second charging communication port S-, and a first charging connection. Confirm the port CC1, the second charging connection confirmation port CC2, the positive terminal A+ of the low-voltage auxiliary power supply, and the negative terminal A- of the low-voltage auxiliary power supply. Among them, the positive terminal DC+ of the DC power supply and the negative terminal DC- of the DC power supply are collectively referred to as the DC power supply port; the first charging communication port S+ and the second charging communication port S- are collectively referred to as the charging communication port; the positive terminal A+ of the low-voltage auxiliary power supply and the low-voltage auxiliary power supply are collectively called the charging communication port. The negative port A- is collectively referred to as a low-voltage auxiliary power supply port; the first charging communication port S+ and the second charging communication port S- are collectively referred to as communication ports. When the insulation detection interface 210 is connected to the DC charging interface 110 of the electric vehicle 100 to be detected, each port in the insulation detection interface 210 is connected with each corresponding port in the DC charging interface 110 one by one.

In a preferred embodiment, the DC charging interface 110 is a DC fast charging vehicle socket, and the insulation detection interface 210 is a DC charging pile plug (or DC charging gun) matching the DC fast charging vehicle socket.

The auxiliary power supply 220 is connected to the low-voltage auxiliary power supply port (ie the positive terminal A+ of the low-voltage auxiliary power supply and the negative terminal A- of the low-voltage auxiliary power supply) in the insulation detection interface 210, and the auxiliary power supply 220 is connected via the DC The charging interface 110 and the low-voltage auxiliary power port in the insulation detection interface 210 supply power to the battery management system BMS (not shown) of the electric vehicle 100 to be detected, so as to wake up the whole vehicle. In one embodiment, the power supply voltage provided by the auxiliary power supply 220 to the low-voltage auxiliary power supply port in the insulation detection interface 210 is 12V-24V.

The electronic control unit ECU230 is connected to the charging communication port (ie the first charging communication port S+, the second charging communication port S-) in the insulation detection interface 210, and the electronic control unit ECU230 is connected to the charging communication port S+. The DC charging interface 110 and the charging communication port and the CAN bus (Controller Area Network) in the insulation detection interface 210 send instructions to the battery management system BMS of the electric vehicle 100 to be detected, and the instructions include: 1) closing the main positive switch 130, main negative switch 140 and fast charging switch 150 connected to the power battery 120; and/or 2) closing the insulation monitoring circuit of the battery management system BMS.

The insulation resistance tester 240 measures the to-be-detected through the DC charging port 110 and the DC power port in the insulation detection port 210 (ie, the DC power positive port DC+, the DC power negative port DC-). The electric vehicle 100 is used for insulation testing of high-voltage circuits when the vehicle is off the assembly line. The insulation resistance tester 240 includes an insulating positive electrode and an insulating negative electrode, and the insulating negative electrode is connected to the ground wire port PE of the equipment. The insulation resistance tester 240 is used to measure the insulation resistance between the test positive electrode and the test negative electrode. value. The specific structure of the insulation resistance tester 240 is a conventional design in the field, and will not be repeated here.

The selection switch 250 is connected between the DC power port of the insulation detection interface 210 and the insulation positive pole of the insulation resistance tester 240, and is used to control the DC power port of the insulation detection interface 210 and the insulation resistance tester 240. The connection between the insulation positive poles of the insulation resistance tester 240. The selection switch 250 is connected between the positive terminal DC+ of the DC power supply, the negative terminal DC- of the DC power supply and the testing positive pole of the insulation resistance tester of the insulation detection interface 210, and the selection switch 250 is used to connect the insulation resistance tester. The test positive pole of the resistance tester 240 can be selectively connected to the positive terminal DC+ of the DC power supply or the negative terminal DC- of the DC power supply in the insulation detection interface 210 .

In the embodiment shown in FIG. 1 , the selection switch 250 is a three-position selection switch. When the selection switch 250 is in the first position, the selection switch 250 interrupts the connection between the DC positive terminal DC+ of the insulation detection interface 210 and the test positive terminal of the insulation resistance tester 240, and the selection switch 250 is interrupted The connection between the DC negative terminal DC- of the insulation detection interface 210 and the test positive pole of the insulation resistance tester 240; when the selection switch 250 is in the second position, the selection switch 250 is connected to the insulation detection interface 210 The direct current positive port DC+ of the insulation resistance tester 240 is connected to the test positive electrode of the insulation resistance tester 240, and the selection switch 250 interrupts the connection between the direct current negative port DC- of the insulation detection interface 210 and the test positive electrode of the insulation resistance tester 240; When the selection switch 250 is in the third position, the selection switch 250 interrupts the connection between the DC positive terminal DC+ of the insulation detection interface 210 and the test positive terminal of the insulation resistance tester 240, and the selection switch 250 is connected to the DC negative terminal DC- of the insulation detection interface 210 and the test positive pole of the insulation resistance tester 240 .

In the specific embodiment shown in FIG. 1 , the selector switch 250 is a three-position self-locking rotary switch (double normally open), and the three-position self-locking rotary switch includes a first sub-switch K11 and a second sub-switch K2, The first sub-switch K11 is connected between the positive terminal DC+ of the DC power supply of the insulation detection interface 210 and the test positive pole of the insulation resistance tester 240 ; the second sub-switch K2 is connected to the insulation detection interface 210 between the negative terminal DC- of the DC power supply and the positive test pole of the insulation resistance tester 240; the control terminal of the first sub-switch K1 and the control terminal of the second sub-switch K2 are driven in the same direction (that is, the two control terminals moved in the same direction). When the control terminal of the first sub-switch K1 and the control terminal of the second sub-switch K2 are driven to the first position (that is, when the selection switch 250 is at the first position), the first sub-switch K1 is turned off and the first sub-switch K2 is turned off. The two sub-switches K2 are turned off; when the control terminal of the first sub-switch K1 and the control terminal of the second sub-switch K2 are driven to the second position (that is, when the selection switch 250 is in the second position), the first sub-switch 250 is in the second position. The sub-switch K11 is turned on and the second sub-switch K2 is turned off; when the control terminal of the first sub-switch K1 and the control terminal of the second sub-switch K2 are driven to the third position (that is, the selection switch 250 is in the third position three bits), the first sub-switch K1 is turned off, and the second sub-switch K2 is turned on.

Please refer to FIG. 3 , which is a flowchart of the detection method of the vehicle end-of-line insulation detection device 200 for electric vehicles shown in FIG. 1 . The detection method shown in FIG. 3 includes the following steps.

Step 310 , connect (or butt) the insulation detection interface 210 of the vehicle off-line insulation detection device 200 with the DC charging interface 110 of the electric vehicle 100 to be detected.

Step 320: The auxiliary power supply 220 supplies the battery to the battery via the connected DC charging interface 110 and the low-voltage auxiliary power supply ports in the insulation detection interface 210 (ie, the positive terminal A+ of the low-voltage auxiliary power supply and the negative terminal A- of the low-voltage auxiliary power supply). The battery management system BMS of the electric vehicle 100 to be detected is powered to wake up the whole vehicle.

Step 330: After the whole vehicle is woken up, the electronic control unit ECU230 connects the charging communication ports in the DC charging interface 110 and the insulation detection interface 210 (ie the first charging communication port S+, the second charging The communication port S-) sends an instruction to the battery management system BMS of the electric vehicle 100 to be detected, and the instruction includes: 1) closing the main positive switch 130, the main negative switch 140 and fast charging connected to the power battery 120 switch 150; and/or 2) close the insulation monitoring circuit of the battery management system BMS.

Step 340 , after the battery management system BMS executes the instruction, the insulation resistance tester 240 performs the high-voltage circuit insulation test for the electric vehicle 100 to be tested when the vehicle is offline through the selection switch 250 . Specifically, the electric vehicle 100 to be tested is tested by the insulation resistance tester 240 via the selection switch 250 and the DC power port in the connected DC charging interface 110 and the insulation detection interface 210 . Carry out the insulation test of the high-voltage circuit of the whole vehicle off the assembly line.

The "insulation detection of the high-voltage circuit of the electric vehicle 100 to be tested when the whole vehicle is off-line" includes: measuring the insulation resistance of the high-voltage positive circuit to the vehicle body, and testing the insulation resistance of the high-voltage negative circuit to the vehicle body.

Step 340 specifically includes two steps: (1) switch the selection switch 250 to the second position (that is, connect the positive terminal DC+ of the DC power supply to the insulating positive electrode), and measure the high-voltage positive electrode by the insulation resistance tester 240 (2) Switch the selection switch 250 to the third position (that is, connect the negative terminal DC- of the DC power supply to the insulation positive pole), and measure the high-voltage negative pole by the insulation resistance tester 240 Insulation resistance of the circuit to the body.

It should be noted that, in step 340, step (1) may be performed first and then step (2), or step (2) may be performed first and then step (1).

Step 350 , after the insulation detection of the high-voltage circuit of the whole vehicle is completed, the insulation detection data is sent to the local display 300 . The local display 300 may be a factory MES system (manufacturing execution system, manufacturing execution system) and equipment of an operator.

To sum up, the vehicle end-of-line insulation detection device 200 in the present invention performs communication and vehicle end-of-line insulation detection via (or using) the vehicle-mounted DC charging interface 110 to the electric vehicle 100 to be tested. In this way, not only can the detection of the insulation performance of the whole vehicle be realized conveniently and quickly, but also safety accidents can be avoided during the operation of the workers.

In the present invention, "connected", "connected", "connected", "connected" and the like refer to words that are electrically connected, and unless otherwise specified, refer to direct or indirect electrical connection. "Coupling" herein refers to an indirect or direct electrical connection, and an indirect connection may be an electrical connection through one or more electrical devices (such as resistors, capacitors, inductors, etc.).

The foregoing description has fully disclosed specific embodiments of the present invention. It should be pointed out that any changes made by those skilled in the art to the specific embodiments of the present invention will not depart from the scope of the claims of the present invention. Accordingly, the scope of the claims of the present invention is not limited to the foregoing specific embodiments.

Claims (10)

1. a vehicle off-line insulation detection equipment for electric vehicle, is characterized in that, it comprises: An insulation detection interface, which is used for connecting with a DC charging interface of an electric vehicle to be detected, the insulation detection interface includes a DC power port, a device ground port, a charging communication port, a charging connection confirmation port and an auxiliary power port, the insulation detection interface Each port in the detection interface is docked with each corresponding port in the DC charging interface one by one; An electronic control unit, which is connected to the charging communication port in the insulation detection interface, and the electronic control unit sends the battery of the electric vehicle to be detected to the charging communication port in the connected DC charging interface and the insulation detection interface. The management system sends instructions; An insulation resistance tester, comprising an insulating positive electrode and an insulating negative electrode, the insulating negative electrode is connected to the ground wire port of the device, and the insulation resistance tester is used to measure the insulation resistance value between the testing positive electrode and the testing negative electrode; A selection switch, which is connected between the DC power port of the insulation detection interface and the insulation positive pole of the insulation resistance tester, is used to control the connection between the DC power port and the insulation positive pole. 2. The electric vehicle off-line insulation detection device according to claim 1, wherein the instruction comprises: closing the main negative switch, main positive switch and fast charging switch connected to the power battery in the electric vehicle to be detected; and/or Close the insulation monitoring circuit of the battery management system. 3. electric vehicle complete vehicle off-line insulation detection equipment according to claim 1, is characterized in that, The DC power port includes a DC power positive port and a DC power negative port; The selection switch is connected between the positive terminal of the DC power supply, the negative terminal of the DC power supply and the testing positive pole of the insulation resistance tester of the insulation detection interface, and the selection switch is used to connect the positive testing pole to the DC power supply The positive port or the negative port of the DC power supply can be optionally connected. 4. The electric vehicle complete vehicle off-line insulation detection equipment according to claim 3, is characterized in that, the charging communication port includes a first charging communication port and a second charging communication port; The charging connection confirmation port includes a first charging connection confirmation port and a second charging connection confirmation port; The auxiliary power supply port includes an auxiliary power supply positive terminal and an auxiliary power supply negative terminal. 5. The electric vehicle complete vehicle off-line insulation detection equipment according to claim 3, is characterized in that, The selector switch is a three-position selector switch, When the selection switch is in the first position, the selection switch interrupts the connection between the DC positive terminal and the test positive terminal, and interrupts the connection between the DC negative terminal and the test positive terminal; When the selection switch is in the second position, the selection switch connects the DC positive terminal and the test positive terminal, and interrupts the connection between the DC negative terminal and the test positive terminal; When the selection switch is in the third position, the selection switch interrupts the connection between the DC positive terminal and the test positive terminal, and connects the DC negative terminal and the test positive terminal. 6. The electric vehicle complete vehicle off-line insulation detection equipment according to claim 5, is characterized in that, The selection switch is a three-position self-locking rotary switch, the three-position self-locking rotary switch includes a first sub-switch and a second sub-switch, and the first sub-switch is connected to the positive terminal of the DC power supply and the test positive terminal between; the second sub-switch is connected between the negative terminal of the DC power supply and the positive test positive; When the selection switch is in the first position, the first sub-switch is turned off and the second sub-switch is turned off; when the selection switch is in the second position, the first sub-switch is turned on and the second sub-switch is turned off; When the selection switch is in the third position, the first sub-switch is turned off and the second sub-switch is turned on. 7. A detection method for the off-line insulation detection equipment of an electric vehicle complete vehicle as claimed in claim 1-6, characterized in that, it comprises the steps: connecting the insulation detection interface of the vehicle off-line insulation detection equipment with the DC charging interface of the electric vehicle to be detected; supplying power to the electric vehicle to be detected via the auxiliary power port in the connected DC charging interface and the insulation detection interface to wake up the whole vehicle; After the whole vehicle is woken up, the electronic control unit sends an instruction to the battery management system of the electric vehicle to be detected via the connected DC charging interface and the charging communication port in the insulation detection interface; After the battery management system executes the instruction, the insulation resistance tester performs the high-voltage circuit insulation detection of the whole vehicle off the assembly line for the electric vehicle to be detected through the selection switch. 8. detection method according to claim 7, is characterized in that, The instructions include: closing the main negative switch, main positive switch and fast charging switch connected to the power battery in the electric vehicle to be detected; and/or Close the insulation monitoring circuit of the battery management system. 9. The detection method according to any one of claims 7-8, characterized in that, The step of "using the insulation resistance tester to conduct the high-voltage loop insulation detection of the electric vehicle to be detected through the selection switch when the whole vehicle is off the assembly line" includes: Connect the positive terminal of the DC power supply to the insulating positive electrode, and measure the insulation resistance of the high-voltage positive circuit to the vehicle body by the insulation resistance tester; The negative terminal of the DC power supply is connected to the insulating negative electrode, and the insulation resistance of the high-voltage negative circuit to the vehicle body is measured by the insulation resistance tester. 10. The detection method according to any one of claims 7-8, characterized in that, After the insulation test of the high-voltage circuit of the whole vehicle is completed, the insulation test data is sent to the local display, The local display is the facility's Manufacturing Execution System or an operator's device.

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