A pre-charge resistance durability test system and test method

Abstract

The application discloses a pre-charging resistance durability test system and a test method, and belongs to the field of resistance test. The test system comprises a high-voltage direct-current power supply, a low-voltage direct-current power supply, a vehicle controller, a multi-channel temperature rise recorder, a pre-charging resistance, a thermostat, a pre-charging contactor, a main contactor, a charging capacitor, an IGBT, a driving motor and a motor controller. The positive pole of the high-voltage direct-current power supply, the pre-charging resistance, the pre-charging contactor, the charging capacitor and the negative pole of the high-voltage direct-current power supply are connected in series to form a charging circuit. The input end of the main contactor is connected with the input end of the pre-charging resistance, the output end of the main contactor is connected with the output end of the pre-charging contactor, the driving motor is electrically connected with the charging capacitor through the IGBT to form a discharging circuit, the charging capacitor and the IGBT are connected with the motor controller, the vehicle controller and the pre-charging contactor are electrically connected with the low-voltage direct-current power supply, and the pre-charging resistance durability test system is used for durability test of the connected pre-charging resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resistance test, and particularly relates to a pre-charging resistance durability test system and a test method. BACKGROUND

[0002] The high-voltage integrated controller of an electric vehicle has a large capacitor C. If there is no pre-charging circuit, when the high-voltage contactor of the vehicle is attracted, the high voltage is connected, one end of the contactor is connected with the battery, and the other end is connected with the capacitor C. At this time, the voltage of the battery is relatively high, and the voltage of the high-voltage platform vehicle is generally about 600V, while the voltage on the capacitor C is close to 0V. At this time, du=600V-0V=600V, according to the formula I=C×du / dt, the charging current can reach thousands of amperes at this moment, which can easily damage the contactor and other high-voltage devices. The pre-charging circuit is to parallel a pre-charging resistor and a pre-charging contactor at both ends of the main contactor. When the high voltage of the vehicle is connected, the pre-charging circuit contactor is closed first. Due to the existence of the resistor R, the current is small, and the capacitor is gradually charged. When the voltage of the capacitor is close to that of the battery, the main contactor is closed, and then the pre-charging contactor is disconnected. The function of the pre-charging circuit is to avoid the large current impact in the power-on process, and to protect the contactor and high-voltage devices.

[0003] There are many controllers on the electric vehicle, such as motor controllers, air pump controllers, oil pump controllers and DC choppers, etc. Each controller needs a pre-charging circuit, and the performance of the pre-charging resistor directly affects the reliability of the electric vehicle parts.

[0004] During the power-on process of the vehicle, the pre-charging resistor can play a role in pre-charging the input end capacitor of each high-voltage part connected with the power battery. If the pre-charging process fails, it will directly lead to the vehicle unable to be connected with high voltage. Therefore, the pre-charging resistor plays an indispensable and important role in the starting process of the vehicle. In order to ensure that the electric vehicle can be started normally and quickly, the durability of the pre-charging resistor needs to meet the use requirements of the electric vehicle.

[0005] At present, the electric vehicle industry has not yet developed a method for simulating the system of the vehicle fast power-on and power-off. It is necessary to develop a pre-charging resistor fast power-on and power-off durability test method in view of the durability use requirements of the pre-charging resistor in the vehicle. SUMMARY

[0006] In order to solve the above technical problems, the application provides a pre-charging resistance durability test system and a test method.

[0007] First aspect

[0008] The application provides a pre-charge resistance durability test system, comprising: a high-voltage direct-current power supply, a low-voltage direct-current power supply, a vehicle controller, a multi-channel temperature rise recorder, a pre-charge resistance, a thermostat, a pre-charge contactor, a main contactor, a charging capacitor, an IGBT, a driving motor and a motor controller.

[0009] The positive electrode of the high-voltage direct-current power supply, the pre-charge resistance, the pre-charge contactor, the charging capacitor and the negative electrode of the high-voltage direct-current power supply are sequentially connected in series to form a charging circuit, and the charging capacitor is used for simulating a support capacitor value of the motor controller.

[0010] The pre-charge resistance is arranged in the thermostat, and the thermostat is used for simulating an environmental temperature of the pre-charge resistance in the vehicle.

[0011] The temperature rise line of the multi-channel temperature rise recorder is attached to the surface of the pre-charge resistance, and is used for collecting the surface temperature of the pre-charge resistance.

[0012] The input end of the main contactor is connected with the input end of the pre-charge resistance, and the output end of the main contactor is connected with the output end of the pre-charge contactor.

[0013] The vehicle controller is electrically connected with the pre-charge contactor, the main contactor and the motor controller respectively, and is used for controlling the opening or closing of the pre-charge contactor and the main contactor.

[0014] The driving motor is electrically connected with the charging capacitor and the IGBT to form a discharging circuit, and the IGBT is used for controlling the opening or closing of the discharging circuit.

[0015] The charging capacitor and the IGBT are both connected with the motor controller, and the motor controller is used for collecting the voltage between the charging capacitor and controlling the opening or closing of the IGBT.

[0016] The vehicle controller and the pre-charge contactor are both electrically connected with the low-voltage direct-current power supply, and the low-voltage direct-current power supply is used for providing low-voltage for the vehicle controller and the motor controller.

[0017] The second aspect

[0018] The application provides a pre-charge resistance durability test method, which is applied to the pre-charge resistance durability test system of the first aspect and comprises the following steps.

[0019] S101: Pre-processing is performed on the pre-charge resistance durability test system.

[0020] S102: receiving a test request, the vehicle controller sends a first control instruction, the pre-charge contactor is closed, the high-voltage DC power supply is used to charge the charging capacitor with a first preset voltage value, and the first voltage value of the charging capacitor is collected through the motor controller and fed back to the vehicle controller to determine whether the first voltage value is within a first preset range, if the first voltage value is within the first preset range, S103 is entered, otherwise, S107 is entered;

[0021] S103: in the case that the absolute value of the difference between the first voltage value and the first preset voltage value is less than a preset voltage difference, a second control instruction is sent, the main contactor is closed, and the pre-charge contactor is disconnected, the charging capacitor is fully charged, and the second voltage value of the charging capacitor is collected through the motor controller and fed back to the vehicle controller;

[0022] S104: determining whether the second voltage value is within a second preset range, if the second voltage value is within the second preset range, a pre-charge completion instruction is fed back to the vehicle controller through the motor controller, a discharge request is sent, otherwise, S107 is entered;

[0023] S105: the motor controller receives the discharge request, the discharge circuit is turned on, the charge of the charging capacitor is discharged, the third voltage value of the charging capacitor is collected through the motor controller, and it is determined whether the third voltage value is lower than the second preset voltage value, if the third voltage value is lower than the second preset voltage value, an active discharge completion instruction is fed back to the vehicle controller, the discharge is completed, otherwise, S107 is entered;

[0024] S106: setting a preset cycle number, and repeatedly executing S102 to S105;

[0025] S107: the vehicle controller sends a third control instruction to stop the test.

[0026] Compared with the prior art, the present application has at least the following beneficial effects:

[0027] In the present application, the pre-charge resistance durability test system is provided with a charging circuit including a pre-charge resistance and a discharge circuit including a driving motor, the pre-charge resistance is tested in the pre-charge resistance durability test system according to the durability use requirements for a preset cycle number by simulating the power-on and power-off process of the vehicle in the actual application, the surface temperature of the pre-charge resistance is collected in real time through the multi-channel temperature rise recording set, the voltage value across the charging capacitor is collected in real time through the motor controller, if the surface temperature is abnormal, the voltage value across the charging capacitor does not meet the requirements of the vehicle power-on and power-off, or the preset cycle number is not reached during the test, the pre-charge resistance durability test system is stopped in time by the vehicle controller, whether the pre-charge resistance meets the durability use requirements is finally determined through the test result, the operation is simple, the test result is reliable, and guidance is provided for the selection of the pre-charge resistance. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above features, technical characteristics, advantages and implementation manners of the present application will be further described in a clear and understandable manner in combination with the preferred embodiments and the accompanying drawings.

[0029] Figure 1 is a structural schematic diagram of a pre-charge resistance durability test system provided by the present application;

[0030] Figure 2 is a flow schematic diagram of a pre-charge resistance durability test method provided by the present application. DETAILED DESCRIPTION

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the specific implementation manners of the present application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without any creative effort, and other embodiments can also be obtained.

[0032] In order to make the drawings simple, only the parts related to the present application are shown in each drawing, which do not represent the actual structure of the product. In addition, in order to make the drawings simple and easy to understand, in some drawings, only one of the parts with the same structure or function is shown, or only one of them is marked. In this document, "one" not only means "only one", but also means "more than one" situation.

[0033] It should be further understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0034] In this document, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] In addition, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0036] Embodiment one

[0037] In one embodiment, reference is made to the drawings attached to the specification Figure 1The application provides a pre-charging resistor 5 durability test system.

[0038] The application provides a pre-charging resistor 5 durability test system, which comprises a high-voltage direct-current power supply 1, a low-voltage direct-current power supply 2, a vehicle controller 3, a multi-channel temperature rise recorder 4, a pre-charging resistor 5, a thermostat 6, a pre-charging contactor 7, a main contactor 8, a charging capacitor 9, an IGBT 10, a driving motor 11 and a motor controller 12.

[0039] The thermostat 6 is used to provide a high-temperature environment temperature simulating a whole vehicle for the pre-charging resistor 5, for example, a 40 DEG C constant temperature, and the temperature is adjustable, so that the working condition of the whole vehicle can be simulated more accurately.

[0040] The charging capacitor 9 is a thin-film capacitor, and the capacitance value is equal to the support capacitance value of the motor controller 12 (VCU, Vehicular Communication Unit) of the whole vehicle.

[0041] The IGBT 10 (Insulated Gate Bipolar Transistor) is equivalent to a circuit switch and is a three-terminal semiconductor switching device, which can be used for high-efficiency and fast switching in various electronic devices, has the advantages of stable control voltage and strong voltage resistance, and is often used in the variable current system with a direct-current voltage of 500 volts or above. The biggest advantage of the IGBT 10 is that the voltage can be stably controlled, and the voltage resistance is strong, so it is often used on strong current with voltage of dozens to hundreds of volts, and it is not controlled by a mechanical button, but by the motor controller 12.

[0042] Optionally, the pre-charging resistor 5 durability test system further comprises a low-voltage wire harness and a high-voltage wire harness, and different wire harnesses can be selected according to actual needs to build the pre-charging resistor 5 durability test system.

[0043] Specifically, the high-low voltage wire harness is used to connect the vehicle controller 3, the motor controller 12 (MCU, Microcontroller Unit) and the driving motor 11 to form a loop.

[0044] The positive pole of the high-voltage direct-current power supply 1, the pre-charging resistor 5, the pre-charging contactor 7, the charging capacitor 9 and the negative pole of the high-voltage direct-current power supply 1 are sequentially connected in series to form a charging loop, and the charging capacitor 9 is used to simulate the support capacitance value of the motor controller 12.

[0045] The pre-charging resistor 5 is arranged in the thermostat 6, and the thermostat 6 is used to simulate the environment temperature of the pre-charging resistor 5 in the whole vehicle.

[0046] It can be understood that during the working of the pre-charge resistor 5 test system, the ambient temperature of the pre-charge resistor 5 should be the same as the temperature when the whole vehicle starts to run, so as to avoid the influence of the change of the ambient temperature on the test result.

[0047] The temperature rise line of the multi-channel temperature rise recorder 4 is attached to the surface of the pre-charge resistor 5, and is used to collect the surface temperature of the pre-charge resistor 5.

[0048] The input end of the main contactor 8 is connected with the input end of the pre-charge resistor 5, and the output end of the main contactor 8 is connected with the output end of the pre-charge contactor 7.

[0049] The whole vehicle controller 3 is electrically connected with the pre-charge contactor 7, the main contactor 8 and the motor controller 12 respectively, and the whole vehicle controller 3 is used to control the opening or closing of the pre-charge contactor 7 and the main contactor 8.

[0050] The driving motor 11 is electrically connected through the IGBT 10 and the charging capacitor 9 to form a discharge circuit, and the IGBT 10 is used to control the opening or closing of the discharge circuit.

[0051] It can be understood that for the discharge circuit, by setting the IGBT 10, the control of the high-voltage circuit can be adapted, and the control instruction is sent by the motor controller 12 to control the opening or closing of the discharge circuit.

[0052] The charging capacitor 9 and the IGBT 10 are both connected with the motor controller 12, and the motor controller 12 is used to collect the voltage across the charging capacitor 9 and to control the opening or closing of the IGBT 10.

[0053] The whole vehicle controller 3 and the pre-charge contactor 7 are both electrically connected with the low-voltage direct-current power supply 2, and the low-voltage direct-current power supply 2 is used to provide low-voltage for the whole vehicle controller 3 and the motor controller 12.

[0054] In a possible implementation, the pre-charge resistor 5 durability test system further comprises a main drive fuse 13.

[0055] The main drive fuse 13 is connected in series between the charging capacitor 9 and the pre-charge contactor 7, and is used to protect the charging circuit from short circuit.

[0056] In a possible implementation, the pre-charge resistor 5 durability test system further comprises a passive discharge resistor 14.

[0057] The passive discharge resistor 14 is connected in parallel across the charging capacitor 9.

[0058] The passive discharge resistor 14 is set to avoid the situation that the charging capacitor 9 cannot be discharged in the case of sudden conditions in the discharge circuit, and is used to discharge the electric quantity of the charging capacitor 9.

[0059] Compared with the prior art, the present application has at least the following beneficial effects:

[0060] In the present application, the pre-charge resistor 5 durability test system is provided with a charging circuit including the pre-charge resistor 5 and a discharging circuit including the driving motor 11. By simulating the power-on and power-off process of the whole vehicle in actual application, the pre-charge resistor 5 is subjected to cycle test according to the preset cycle number of durability use requirement in the pre-charge resistor 5 durability test system. The surface temperature of the pre-charge resistor 5 is collected in real time by the multi-channel temperature rise recording set, and the voltage value across the charging capacitor 9 is collected in real time by the motor controller 12. During the test process, if the surface temperature is abnormal, the voltage value across the charging capacitor 9 does not meet the power-on and power-off requirement of the whole vehicle, or the preset cycle number is not reached, the pre-charge resistor 5 durability test system is stopped in time by the whole vehicle controller 3. Whether the pre-charge resistor 5 meets the durability use requirement is finally determined by the test result. The operation is simple, the test result is reliable, and guidance is provided for the selection of the pre-charge resistor 5.

[0061] Embodiment two

[0062] In one embodiment, referring to the accompanying drawings Figure 2 The present application provides a flowchart of a pre-charge resistor 5 durability test method.

[0063] The present application provides a pre-charge resistor 5 durability test method, which is applied to the pre-charge resistor 5 durability test system of embodiment one, and includes the following steps.

[0064] S101: Pretreatment is performed on the pre-charge resistor 5 durability test system.

[0065] It can be understood that before the test, irrelevant factors or starting test parameters need to be debugged to avoid inaccurate test results caused by various factors.

[0066] In one possible implementation, S101 specifically includes the following steps.

[0067] S1011: According to the driving motor 11 parameters, the motor controller 12 parameters and the simulated whole vehicle power-on and power-off parameters, the program of the whole vehicle controller 3 and the motor controller 12 is matched, and the program is written.

[0068] S1012: According to the whole vehicle operating temperature, the temperature of the constant temperature box 6 is set so that the pre-charge resistor 5 is at the whole vehicle operating temperature.

[0069] The temperature of the thermostat 6 can set the relevant parameter value of the temperature control program in the thermostat 6 according to the actual use environment of the pre-charging resistor 5 in the whole vehicle, and start the temperature control program to simulate the environmental temperature of the pre-charging resistor 5 in the whole vehicle, for example, set the highest environmental temperature and the lowest environmental temperature of the temperature control program according to the actual use environment of the pre-charging resistor 5 in the whole vehicle.

[0070] S1013: Turn on the high-voltage DC power supply 1, set the output voltage of the high-voltage DC power supply 1 according to the working voltage of the power battery in the whole vehicle, and set the current limiting value of the high-voltage DC power supply 1 according to the maximum impact current of the pre-charging resistor 5 in the running state of the whole vehicle.

[0071] It can be understood that by setting the current limiting value of the high-voltage DC power supply 1, the high-voltage DC power supply 1 can automatically limit the impact current when the impact current is greater than the expected impact current, which can protect the safety of the pre-charging resistor 5 test system.

[0072] Specifically, the output voltage of the high-voltage DC power supply 1 is set to the maximum working voltage of the power battery in the whole vehicle, so as to fully examine the durability of the pre-charging resistor 5 under extreme working conditions. At the same time, the current limiting value of the high-voltage DC power supply 1 is set to the maximum impact current of the pre-charging resistor 5 in the whole vehicle.

[0073] S1014: Turn on the low-voltage DC power supply 2, adjust the low-voltage DC power supply 2 to the low-voltage power supply rated voltage, and set the current limiting value of the low-voltage DC power supply 2 according to the maximum impact current of the whole vehicle in the low-voltage loop.

[0074] Optionally, the low-voltage power supply rated voltage is 24V, and by setting the low-voltage DC power supply 2, low-voltage power supply is provided for each part of the pre-charging resistor 5 durability test system.

[0075] S101A: Send a forced discharge instruction to the motor controller 12 through the vehicle controller 3 to control the IGBT 10 to open the tube, and use the driving motor 11 to discharge the electric quantity of the charging capacitor 9.

[0076] It can be understood that before starting the durability test, there may be residual electric quantity in the charging capacitor 9, and if not discharged in advance, it may cause inaccurate charging time for the pre-charging resistor 5 durability test system, causing unnecessary influence, therefore, the residual electric quantity of the charging capacitor 9 is discharged as much as possible before the test, to ensure the reliability of the test process.

[0077] S102: receiving a test request, the vehicle control unit 3 sends a first control instruction, the pre-charge contactor 7 is closed, the high-voltage DC power supply 1 is used to charge the charging capacitor 9 with a first preset voltage value, and the first voltage value of the charging capacitor 9 is collected through the motor controller 12 and fed back to the vehicle control unit 3 to determine whether the first voltage value is within the first preset range. If the first voltage value is within the first preset range, S103 is entered, otherwise S107 is entered.

[0078] The test request simulates the request triggered by the vehicle key switch START gear starting the vehicle, which can ensure that the test state during the test is the same as the vehicle operating state, and more accurate test results can be obtained.

[0079] It should be noted that the first preset voltage value and the first preset range can be selected by those skilled in the art according to actual conditions. In actual application, due to different vehicle conditions, the supply voltage provided by the high-voltage DC power supply 1 during charging is often different, and accordingly the test conditions for the durability of the pre-charge resistor 5 are also different.

[0080] In one possible implementation, S102 specifically includes:

[0081] S1021: receiving a test request simulating the vehicle starting;

[0082] S1022: the vehicle control unit 3 sends a first control instruction to close the pre-charge contactor 7 by outputting a low-voltage rated voltage to the pre-charge contactor 7.

[0083] S102A: if the absolute value of the difference between the first voltage value and the preset voltage value is greater than the preset voltage difference, it is prompted that the pre-charge resistor 5 fails the test, the low-voltage DC power supply 2 switch is turned off, and the test is stopped.

[0084] It can be understood that if the absolute value of the difference between the first voltage value and the first preset voltage value is greater than the preset voltage difference, it indicates that the pre-charge resistor 5 does not effectively protect the charging circuit and does not avoid the large current impact on various devices during the power-on process. At this time, the pre-charge resistor 5 can be directly determined as failing the test.

[0085] S103: if the absolute value of the difference between the first voltage value and the first preset voltage value is less than the preset voltage difference, a second control instruction is sent to close the main contactor 8 and disconnect the pre-charge contactor 7, the charging capacitor 9 is fully charged, and the second voltage value of the charging capacitor 9 is collected through the motor controller 12 and fed back to the vehicle control unit 3.

[0086] Optionally, the preset voltage difference is 20V.

[0087] It can be understood that when the absolute value of the difference between the first voltage value and the first preset voltage value is less than the preset voltage difference, it indicates that the preset voltage difference between the two ends of the charging capacitor 9 and the high-voltage power supply is not more than 20V, at this time, the main contactor 8 is closed, the pre-charging contactor 7 is disconnected, and the charging capacitor 9 is gradually charged to prevent the high voltage from directly charging the charging capacitor 9 with large current to damage the durability test system of the pre-charging resistor 5.

[0088] S104: Determine whether the second voltage value is within the second preset range. If the second voltage value is within the second preset range, feed back the pre-charging completion instruction to the vehicle controller 3 through the motor controller 12, and issue a discharge request, otherwise, go to S107.

[0089] Optionally, the second preset range is within ±20V of the first preset voltage value.

[0090] It should be noted that during the charging process, if the voltage at both ends of the charging capacitor 9 is not within the range of ±20V of the output voltage of the high-voltage DC power supply 1 after 1s of charging, it indicates that the voltage is abnormal, and this condition indicates that the pre-charging resistor 5 has not passed the simulated durability test required by the vehicle.

[0091] S105: The motor controller 12 receives the discharge request, turns on the discharge loop, and discharges the charge of the charging capacitor 9. The third voltage value of the charging capacitor 9 is collected through the motor controller 12, and it is determined whether the third voltage value is lower than the second preset voltage value. If the third voltage value is lower than the second preset voltage value, feed back the active discharge completion instruction to the vehicle controller 3, complete the discharge, otherwise, go to S107.

[0092] Optionally, the second preset voltage value is 60V.

[0093] It can be understood that if the voltage at both ends of the charging capacitor 9 is above 60V after 1s of discharging, it indicates that the voltage is abnormal, and the vehicle controller 3 issues a third control instruction to stop the test.

[0094] In one possible implementation, S105 specifically includes:

[0095] S1051: The motor controller 12 receives the active discharge instruction, controls the IGBT 10 to open the tube, the discharge loop is turned on, and the charge of the charging capacitor 9 is discharged through the coil winding of the driving motor 11;

[0096] S1052: Active discharge is completed, and the active discharge completion instruction is fed back to the vehicle controller 3.

[0097] S106: Set a preset number of cycles, and repeatedly execute S102 to S105.

[0098] Wherein, the person skilled in the art can select the size of the preset cycle number according to the actual situation. It can be understood that, due to different vehicle conditions or different vehicle parameters, the requirements for the pre-charge resistor 5 used in different vehicles are also different, therefore, in the pre-charge resistor 5 durability test system, the setting of the preset cycle number is not the larger the better, but the preset cycle number should be reasonably set according to the vehicle running condition.

[0099] S106A: record the surface temperature of the pre-charge resistor 5 by the multi-channel temperature rise recorder 4, and form a temperature rise curve, in the case of abnormal temperature rise curve, turn off the low-voltage DC power supply 2 switch and stop the test.

[0100] It can be understood that, by monitoring the surface temperature of the pre-charge resistor 5 in real time, it can be judged in real time during the test of the preset cycle number that if the pre-charge resistor 5 is abnormal, the low-voltage DC power supply 2 is turned off by the operator to stop the test, indicating that the pre-charge resistor 5 being tested does not meet the durability test requirements.

[0101] S107: the vehicle controller 3 sends a third control instruction to stop the test.

[0102] Compared with the prior art, the present application has at least the following beneficial effects:

[0103] In the present application, the pre-charge resistor 5 durability test system is provided with a charging circuit including the pre-charge resistor 5 and a discharging circuit including the driving motor 11, the pre-charge resistor 5 is tested in the pre-charge resistor 5 durability test system according to the durability use requirements by simulating the vehicle power-on and power-off process in actual application, the surface temperature of the pre-charge resistor 5 is collected in real time by the multi-channel temperature rise recorder 4, the voltage value across the charging capacitor 9 is collected in real time by the motor controller 12, during the test, if the surface temperature is abnormal, the voltage value across the charging capacitor 9 does not meet the vehicle power-on and power-off requirements or the preset cycle number is not reached, the pre-charge resistor 5 durability test system is controlled by the vehicle controller 3 to stop the test in time, whether the pre-charge resistor 5 meets the durability use requirements is finally determined by the test result, the operation is simple, the test result is reliable, and the selection of the pre-charge resistor 5 is guided.

[0104] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present application, and it should be noted that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which should be considered as the protection scope of the present application.

Claims

1. A pre-charge resistor durability testing system, characterized in that, include: High-voltage DC power supply, low-voltage DC power supply, vehicle controller, multi-channel temperature rise recorder, pre-charge resistor, constant temperature chamber, pre-charge contactor, main contactor, charging capacitor, IGBT, drive motor and motor controller; The positive terminal of the high-voltage DC power supply, the pre-charging resistor, the pre-charging contactor, the charging capacitor, and the negative terminal of the high-voltage DC power supply are connected in series to form a charging circuit. The charging capacitor is used to simulate the supporting capacitance value of the motor controller. The pre-charge resistor is placed in a constant temperature chamber, which is used to simulate the ambient temperature of the pre-charge resistor in the vehicle. The temperature rise line of the multi-channel temperature rise recorder is attached to the surface of the pre-charge resistor to collect the surface temperature of the pre-charge resistor. The input terminal of the main contactor is connected to the input terminal of the pre-charge resistor, and the output terminal of the main contactor is connected to the output terminal of the pre-charge contactor. The vehicle controller is electrically connected to the precharge contactor, the main contactor, and the motor controller, respectively. The vehicle controller is used to control the opening or closing of the precharge contactor and the main contactor. The drive motor is electrically connected to the IGBT and the charging capacitor to form a discharge circuit, and the IGBT is used to control the opening or closing of the discharge circuit; Both the charging capacitor and the IGBT are electrically connected to the motor controller. The motor controller is used to collect the voltage across the charging capacitor and to control the opening or closing of the IGBT. Both the vehicle controller and the precharge contactor are electrically connected to the low-voltage DC power supply, which provides low voltage to the vehicle controller and the motor controller. The pre-charge resistor durability test system also includes a main drive fuse. The main drive fuse is connected in series between the charging capacitor and the pre-charge contactor to provide short-circuit protection for the charging circuit; The pre-charge resistor durability test method of the pre-charge resistor durability test system specifically includes: S101: Preprocess the pre-charge resistor durability test system; S102: Upon receiving a test request, the vehicle controller issues a first control command to close the pre-charge contactor, charge the charging capacitor with the high-voltage DC power supply at a first preset voltage value, and collect the first voltage value of the charging capacitor through the motor controller and feed it back to the vehicle controller. The controller determines whether the first voltage value is within a first preset range. If the first voltage value is within the first preset range, proceed to S103; otherwise, proceed to S107. S103: When the absolute value of the difference between the first voltage value and the first preset voltage value is less than the preset voltage difference, a second control command is issued to close the main contactor and open the pre-charge contactor to fully charge the charging capacitor. The second voltage value of the charging capacitor is collected by the motor controller and fed back to the vehicle controller. S104: Determine whether the second voltage value is within the second preset range. If the second voltage value is within the second preset range, then send a charging completion command to the vehicle controller through the motor controller and issue a discharge request. Otherwise, proceed to S107. S105: The motor controller receives the discharge request, connects the discharge circuit, discharges the charge of the charging capacitor, collects the third voltage value of the charging capacitor through the motor controller, and determines whether the third voltage value is lower than the second preset voltage value. If the third voltage value is lower than the second preset voltage value, it sends an active discharge completion command to the vehicle controller to complete the discharge; otherwise, it proceeds to S107. S106: Set a preset number of cycles and repeat S102 to S105; S107: The vehicle controller issues a third control command to stop the test; Specifically, S101 includes: S1011: Based on the drive motor parameters, the motor controller parameters, and the simulated vehicle power-on / off parameters, match the programs of the vehicle controller and the motor controller, and flash the program. S1012: Set the temperature of the constant temperature chamber according to the vehicle operating temperature so that the pre-charge resistor is at the vehicle operating temperature; S1013: Turn on the high-voltage DC power supply, set the output voltage of the high-voltage DC power supply according to the working voltage of the power battery in the vehicle, and set the current limit value of the high-voltage DC power supply according to the maximum inrush current that the pre-charging resistor withstands during vehicle operation. S1014: Turn on the low-voltage DC power supply, adjust the low-voltage DC power supply to the low-voltage power supply rated voltage, and set the current limiting value of the low-voltage DC power supply according to the maximum inrush current that the vehicle withstands in the low-voltage circuit.

2. The pre-charge resistor durability testing system according to claim 1, characterized in that, The pre-charge resistor durability testing system also includes a passive discharge resistor; The passive discharge resistor is connected in parallel across the charging capacitor.

3. The pre-charge resistor durability testing system according to claim 1, characterized in that, Following S101, the following is also included: S101A: The vehicle controller sends an active discharge command to the motor controller to control the IGBT to turn on, and the drive motor is used to discharge the charge of the charging capacitor.

4. The pre-charge resistor durability testing system according to claim 1, characterized in that, S102 specifically includes: S1021: Receive the test request sent when simulating vehicle startup; S1022: The vehicle controller issues the first control command, which closes the pre-charge contactor by outputting the low-voltage power supply rated voltage to the pre-charge contactor.

5. The pre-charge resistor durability testing system according to claim 1, characterized in that, Following S102, the following is also included: S102A: If the absolute value of the difference between the first voltage value and the first preset voltage value is greater than the preset voltage difference, the pre-charge resistor is prompted that the test has failed, the low-voltage DC power supply switch is turned off, and the test is stopped.

6. The pre-charge resistor durability testing system according to claim 1, characterized in that, Specifically, S105 includes: S1051: The motor controller receives the active discharge command, controls the IGBT to turn on, the discharge circuit is connected, and the charge of the charging capacitor is discharged through the coil winding of the drive motor; S1052: Active discharge completed, and a command to complete the active discharge is sent to the vehicle controller.

7. The pre-charge resistor durability testing system according to claim 1, characterized in that, Following S106, the following is also included: S106A: The surface temperature of the pre-charge resistor is recorded by the multi-channel temperature rise recorder, and a temperature rise curve is generated. If the temperature rise curve is abnormal, the low-voltage DC power switch is turned off and the test is stopped.

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