Test method for high-voltage device of electric automobile

Abstract

The invention discloses an electric vehicle high-voltage device test method, which specifically comprises the following steps of: in a vehicle power-off state, performing test configuration preparation based on a vehicle-mounted high-voltage distribution box, and at least replacing a power battery of an original vehicle with an additional high-voltage programmable power supply; starting a high-voltage programmable power supply, and carrying out temperature rise test and evaluation on the high-voltage connection system of the whole vehicle by adopting a preset first current table and a temperature change actual measurement result of the fuse; and adjusting the output current of the high-voltage programmable power supply, carrying out overload test or short-circuit test on the high-voltage connection system of the whole vehicle according to a preset second current table and the actual measurement result of the fusing time of the fuse, and carrying out corresponding evaluation. According to the system-level verification scheme for the high-voltage device of the electric vehicle, the full state of the vehicle used by the user can be effectively verified, and the device defects are fully exposed, so that correction can be carried out in time to reduce vehicle faults.

Description

Technical Field

[0001] This invention relates to the field of automotive electronics and electrical technology, and in particular to a test method for high-voltage devices in electric vehicles that is highly reliable, closely reflects user operating conditions, and has a simple testing process. Background Technology

[0002] With the development and popularization of electric vehicles, the risks of high-voltage electric shock and high-voltage fire are increasing daily. Besides factors inherent to the battery pack itself, the main risks of electric shock and fire are concentrated in the high-voltage connection system. When the high-voltage load (such as PTC or DC-DC converter) malfunctions, it can cause overload of the wiring harness. In extreme cases, a high-voltage short circuit may occur, causing rapid heating of the high-voltage wiring harness, connectors, and fuses. If the fuse fails to blow or takes too long to blow, a fire risk can arise. Therefore, the selection of the wiring harness, its proper matching with fuses, and the performance of the connectors are key indicators in the design of the vehicle's high-voltage connection system.

[0003] In summary, the user scenario for the whole vehicle is a requirement for the overall performance of the high-voltage connection system, rather than a requirement for a single component. Currently, there is only performance verification for individual components, such as verifying only the fusing capacity of a fuse or only the temperature rise capability of a wiring harness, but no system-level verification.

[0004] Specifically, current testing of high-voltage connection systems for electric vehicles mostly involves testing individual components, such as:

[0005] 1) Conduct tests on high-voltage wiring harnesses, including temperature rise, insulation performance, and weather resistance.

[0006] 2) Electrical characteristic tests for high-voltage fuses include internal resistance test, temperature rise test, fusing test, breaking capacity test, and current impulse test.

[0007] The existing testing methods described above only test individual components and do not involve system-level verification or consider the usage conditions of actual vehicle users. For example, in temperature rise testing, the temperature rise requirements for high-voltage wiring harnesses are inconsistent with those for fuses, which may lead to the risk of the wiring harness smoking and softening even if the fuse does not blow. In addition, in terms of high-voltage circuit matching, the fuse should blow before the wiring harness can withstand the load when the circuit is overloaded. However, if the matching is not reasonable, it will cause the temperature of the wiring harness and connectors to rise rapidly, resulting in the risk of spontaneous combustion and electric shock. Summary of the Invention

[0008] In view of the above, the present invention aims to provide a testing method for high-voltage devices in electric vehicles to solve the aforementioned technical problems.

[0009] The technical solution adopted in this invention is as follows:

[0010] This invention provides a testing method for high-voltage devices in electric vehicles, comprising:

[0011] With the vehicle powered off, test configuration preparation is carried out based on the on-board high-voltage power distribution box, which includes at least replacing the original vehicle's power battery with an additional high-voltage programmable power supply.

[0012] Turn on the high-voltage programmable power supply, and use the pre-set first current table and the actual temperature change measurement results of the fuse to conduct temperature rise test and evaluation of the vehicle's high-voltage connection system.

[0013] Adjust the output current of the high-voltage programmable power supply, and according to the pre-set second current table and the measured fuse blowing time, conduct overload or short-circuit tests on the vehicle's high-voltage connection system, and make corresponding evaluations.

[0014] In at least one of the possible implementations, when the vehicle is powered down, the high-voltage maintenance switch is disconnected and the cover of the high-voltage distribution box is removed to make the internal fuses visible.

[0015] Use a high-voltage programmable power supply to replace the power battery and connect it to the fuse input terminal in the high-voltage distribution box;

[0016] A high-voltage electronic load is connected to the output terminal of the fuse in the high-voltage distribution box to simulate the high-voltage load of the entire vehicle.

[0017] In at least one possible implementation, the configuration preparation further includes connecting temperature sensors at different preset locations on the insulation portion of the high-voltage fuse body.

[0018] In at least one possible implementation, the temperature rise test of the vehicle high-voltage connection system includes:

[0019] After the high-voltage programmable power supply is turned on, it outputs the load current according to the test current in the first current table. The first current table includes several pre-calibrated rated currents and corresponding test currents.

[0020] Monitor the temperature rise rate of the fuse using a temperature sensor;

[0021] When the temperature rise rate of the fuse meets the predetermined standard and the temperature does not exceed the predetermined limit of the fuse material, the real-time temperature value of the preset position on the current fuse is obtained.

[0022] Repeat the test according to the first current table and the temperature rise rate monitoring mechanism to complete the temperature rise test of the vehicle's high-voltage connection system.

[0023] In at least one possible implementation, the overload test or short-circuit test process includes:

[0024] After turning on the high-voltage programmable power supply, test its output load current according to some values ​​in the second current table, and start timing simultaneously during the test to record the fuse failure time.

[0025] In at least one possible implementation, the second current table includes: a plurality of test currents greater than a preset multiple of the rated current and a standard range of fusing time corresponding to each test current and related to the rated current.

[0026] Compared with existing technologies, the main design concept of this invention lies in providing a multi-dimensional safety testing process for the high-voltage connection system of the entire vehicle, which closely matches the actual operating conditions of electric vehicles. This allows for the early identification of potential hazards in high-voltage devices, reliably ensuring the safety of the entire vehicle and its occupants. Specifically, with the vehicle powered off, test configuration preparation is carried out based on the onboard high-voltage distribution box. This includes at least replacing the original vehicle's power battery with an additional high-voltage programmable power supply; turning on the high-voltage programmable power supply, and using a pre-set first current table and measured results of fuse temperature changes, conducting temperature rise tests and evaluations of the entire vehicle's high-voltage connection system; adjusting the output current of the high-voltage programmable power supply, and according to a pre-set second current table and measured results of fuse melting time, conducting overload or short-circuit tests of the entire vehicle's high-voltage connection system, and performing corresponding evaluations. The electric vehicle high-voltage device system-level verification scheme provided by this invention can effectively verify the entire state of the vehicle under user operation and fully expose device defects, thereby enabling timely correction to reduce vehicle malfunctions. Attached Figure Description

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0028] Figure 1 This is a schematic diagram of a test method for high-voltage devices in electric vehicles provided in an embodiment of the present invention. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0030] This invention proposes an embodiment of a testing method for high-voltage devices in electric vehicles, specifically, as follows: Figure 1 As shown, it includes:

[0031] Step S1: With the vehicle powered off, prepare for the test configuration based on the on-board high-voltage power distribution box, which includes at least replacing the original vehicle's power battery with an additional high-voltage programmable power supply.

[0032] The configuration preparation process can be summarized as follows: With the vehicle powered down, disconnect the vehicle's high-voltage maintenance switch, disconnect the high-voltage busbar from the power battery input to the PDU (high-voltage distribution box), and replace it with a high-voltage programmable power supply. That is, connect the high-voltage programmable power supply to the input terminal of the vehicle's high-voltage distribution box to power the vehicle. During the test, remove the cover of the high-voltage distribution box to make the internal high-voltage fuse visible. Then, connect the non-vehicle-mounted high-voltage electronic load to the output terminal of the high-voltage distribution box to simulate the vehicle's actual high-voltage load.

[0033] Step S2: Turn on the high-voltage programmable power supply, and use the pre-set first current table and the actual temperature change measurement results of the fuse to conduct a temperature rise test and evaluation of the vehicle's high-voltage connection system.

[0034] The temperature rise test and evaluation of the vehicle high-voltage connection system specifically includes:

[0035] The configuration preparation also includes, further, connecting temperature sensors to different preset positions on the insulation part of the high-voltage fuse body, such as points a and b near the two ends, and point c in the middle.

[0036] Then, turn on the high-voltage programmable power supply and slowly output the load current. The load current can be selected according to the example of the first current table (Table 1) below. This table includes several pre-calibrated rated currents and corresponding test currents. It can also be added that the test voltage is preferably a low voltage of 12V.

[0037] Table 1

[0038]

[0039] The temperature rise rate of the fuse is monitored by a temperature sensor. When the temperature rise rate of the fuse meets the predetermined standard, such as <1 ℃ / 30 min (measured once every 10 min within 30 min, for a total of 3 measurements, with a temperature rise of no more than 1℃) and the temperature does not exceed the temperature limit of the fuse material, the real-time temperature value of the aforementioned preset position (a, b, c) on the current fuse is obtained.

[0040] Repeated tests were conducted according to the first current table and the temperature rise rate monitoring mechanism to carry out temperature rise tests on the high-voltage connection system of the whole vehicle, and the test evaluation was carried out according to the preset temperature rise standard: for example, the temperature rise value of the fuse body (which may also include the examination of the wiring terminals in the above temperature rise test process) is set to not exceed 50K.

[0041] Step S3: Adjust the output current of the high-voltage programmable power supply, and according to the pre-set second current table and the measured fuse blowing time, perform overload test or short circuit test of the vehicle's high-voltage connection system, and make corresponding evaluations.

[0042] The overload test mentioned herein includes:

[0043] After turning on the high-voltage programmable power supply, test its output load current according to some values ​​(relatively low test current values) in the example of the second current table (Table 2) below. During this process, start the timer to record the fuse time. The table below includes several test currents that are greater than the preset multiple of the rated current and the corresponding standard range of fuse time related to the rated current.

[0044] Table 2 (This example table applies to fuses with a rated voltage of <1000V)

[0045]

[0046] In some implementation methods, it is preferable to select 1.35IR and 2.0IR (where IR is the rated current of the fuse) from Table 2 above to start the test, and record the fusing time in real time. It can be added that during the above test, the voltage can also be selected as a low voltage of 12V, and the voltage value should be maintained for more than 30 seconds after the fuse blows. The overload test of each circuit of the whole vehicle is carried out in the above manner, and the evaluation standard is that the measured fusing time should not be greater than the fusing standard specified in Table 2.

[0047] Understandably, the short-circuit test process for fuses is similar to the overload test described above. The main difference is that when adjusting the output current of the programmable power supply, it is preferable to use a relatively high test current value (such as 5.0 IR current) from Table 2 for testing. This will not be elaborated further.

[0048] In summary, the main design concept of this invention lies in providing a multi-dimensional safety testing process for the high-voltage connection system of the entire vehicle, closely aligned with the actual operating conditions of electric vehicles. This allows for the early identification of potential hazards in high-voltage devices, reliably ensuring the safety of the entire vehicle and its occupants. Specifically, with the vehicle powered off, test configuration preparation is performed based on the onboard high-voltage distribution box. This includes at least replacing the original vehicle's power battery with an additional high-voltage programmable power supply; turning on the high-voltage programmable power supply, and using a pre-set first current table and measured fuse temperature changes, conducting a temperature rise test and evaluation of the entire vehicle's high-voltage connection system; adjusting the output current of the high-voltage programmable power supply, and according to a pre-set second current table and measured fuse melting times, conducting overload or short-circuit tests on the entire vehicle's high-voltage connection system, and providing corresponding evaluations. The electric vehicle high-voltage device system-level verification scheme provided by this invention can effectively verify the entire state of the vehicle under user operation and fully expose device defects, enabling timely correction to reduce vehicle malfunctions.

[0049] In this invention, when directional terms are mentioned, they are relative concepts based on the embodiments. Furthermore, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0050] The above description of the structure, features, and effects of the present invention is based on the embodiments shown in the figures. However, the above are only preferred embodiments of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched by those skilled in the art to form a variety of equivalent solutions without departing from or changing the design concept and technical effects of the present invention. Therefore, the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A method of testing a high-voltage device of an electric vehicle, characterized by, The application relates to a high-voltage fuse test device and a test method thereof. In a vehicle power-off state, a test configuration preparation is carried out based on a vehicle-mounted high-voltage distribution box, wherein at least an additional high-voltage programmed power supply is used to replace a power battery of the vehicle; The high-voltage programmed power supply is started, a first current table and a temperature change of a fuse are used to carry out a temperature rise test and evaluation of a high-voltage connection system of the vehicle; The output current of the high-voltage programmed power supply is adjusted, and a second current table and a fuse melting time are used to carry out an overload test or a short circuit test of the high-voltage connection system of the vehicle, and corresponding evaluation is carried out.

2. The electric vehicle high voltage device testing method of claim 1, wherein, In a vehicle power-off state, a vehicle high-voltage maintenance switch is disconnected, and a cover plate of the high-voltage distribution box is removed so that the fuse inside the high-voltage distribution box can be seen; The high-voltage programmed power supply is used to replace the power battery and is connected to an input end of the fuse in the high-voltage distribution box; A high-voltage electronic load is connected to an output end of the fuse in the high-voltage distribution box and is used to simulate the high-voltage load of the vehicle.

3. The electric vehicle high voltage device testing method of claim 2, wherein, The configuration preparation further comprises that temperature sensors are connected to different preset positions of an insulating part on the high-voltage fuse body.

4. The electric vehicle high voltage device testing method of claim 3, wherein, The temperature rise test of the high-voltage connection system of the vehicle comprises: After the high-voltage programmed power supply is started, the high-voltage programmed power supply outputs a load current according to a test current in the first current table, and the first current table comprises a plurality of rated currents and corresponding test currents which are calibrated in advance; The temperature rise rate of the fuse is monitored through the temperature sensors; When the temperature rise rate of the fuse meets the predetermined standard and the temperature does not exceed the predetermined limit of the fuse material, the real-time temperature value of the preset position of the fuse is obtained; The test is repeated according to the first current table and the temperature rise rate monitoring mechanism, and the temperature rise test of the high-voltage connection system of the vehicle is completed.

5. The method of claim 1-4, wherein, The process of the overload test or the short circuit test comprises: After the high-voltage programmed power supply is started, the load current output by the high-voltage programmed power supply is tested according to part of the values in the second current table, and a timing is started synchronously during the test process, so as to record the fuse melting time.

6. The electric vehicle high voltage device testing method of claim 5, wherein, The second current table comprises a plurality of test currents which are greater than a preset multiple of the rated current and a fuse melting time standard range corresponding to each test current and related to the rated current.

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