Method and system for testing durability of power resistor

Abstract

The invention provides a power resistor durability test method and test system. The method is applied to a durability test system, the test system comprises a power supply assembly, a tested resistor, a test box and a temperature acquisition unit, the power supply assembly and the tested resistor are connected to form a test loop, the tested resistor is located in the test box, and the acquisition unit is connected with the test box and used for acquiring temperature information of the test box; the method comprises the steps that the temperature of a test box is adjusted according to the test requirement of a tested resistor, so that the temperature in the test box is matched with the test requirement; according to the rated power consumption of the tested resistor and the test requirement of the tested resistor, the power supply assembly is used for providing periodic test voltage for the tested resistor; determining a plurality of actual measurement resistance values and initial resistance values of the measured resistor at different measurement moments; determining a durability test result of the tested resistor according to the variable quantity of the plurality of actually measured resistance values and the initial resistance value and a resistance value variable quantity threshold value; wherein the resistance value variation threshold value is related to the nominal resistance value of the measured resistor.

Description

Technical Field

[0001] This application relates to the technical field of resistance testing, and particularly relates to a method and a system for testing the durability of a power resistor. Background Art

[0002] With the in-depth development of rail transit electrification, vehicles such as locomotives and multiple units mostly use traction converters as the core devices of their power systems. There are multiple power resistors in the traction converter, such as charging resistors, overvoltage protection resistors, discharge resistors (fast discharge resistors and slow discharge resistors), and grounding resistors. The safety and reliability of the power resistor during operation have a great impact on the safe operation of rail transit vehicles. By conducting durability tests on the power resistor, technical support can be provided for the selection of main components of the converter, simplified design, cost control, health management, and fault troubleshooting.

[0003] In the related art, the durability test of the power resistor usually builds a corresponding test device based on the actual application scenario of the power resistor. This method usually relies on the actual application circuit of the power resistor. For example, in the latter stage of the test circuit, an inverter plus a drive motor is used to form a discharge loop so that the power resistor can be as close as possible to the real working conditions; or, in some related technologies, a DC electronic load is used as the discharge method.

[0004] In the above two related technologies, the use of the latter-stage circuit of the inverter plus the drive motor makes the test platform complex; when using a DC electronic load as the discharge method, the capacitance value of the capacitor will also change during the long-term continuous charging and discharging process, making it difficult to verify whether the change in the resistance value of the resistor or the attenuation of the capacitance value of the capacitor causes the influence in the durability test.

[0005] That is to say, the durability test device for the power resistor in the related art relies on the actual application circuit of the power resistor, with a complex structure, and the test results are easily affected by other components in the circuit, affecting the accuracy of the experimental results. Summary of the Invention

[0006] This application mainly provides a method and a system for testing the durability of a power resistor, and the technical solution of this application is realized as follows:

[0007] In a first aspect, a method for testing the durability of a power resistor is provided. The method is applied to a durability test system, which includes a power supply component, a resistor under test, a test chamber, and a temperature acquisition unit. The power supply component is connected to the resistor under test to form a test circuit. The resistor under test is located inside the test chamber, and the acquisition unit is connected to the test chamber for acquiring the temperature information of the test chamber. The method includes: adjusting the temperature of the test chamber according to the test requirements of the resistor under test so that the temperature inside the test chamber matches the test requirements; providing a periodic test voltage to the resistor under test by using the power supply component according to the rated power consumption of the resistor under test and the test requirements of the resistor under test; determining a plurality of measured resistance values of the resistor under test at different measurement times during the test and the initial resistance value of the resistor under test; determining the durability test result of the resistor under test according to the change amount between the plurality of measured resistance values and the initial resistance value and a resistance value change amount threshold; wherein the resistance value change amount threshold is related to the nominal resistance value of the resistor under test.

[0008] The technical solution of the embodiment of the present application constructs a durability test system that more conforms to the test requirements of power resistors based on the characteristic that the power resistor is an energy-consuming component. When performing a durability test based on this test system, parameters such as the temperature of the test chamber and the test voltage of the resistor under test during the test are flexibly adjusted according to the test requirements of the resistor under test, which can meet the requirements of different test scenarios. Moreover, since this test system avoids the influence of other components in the actual application circuit on the durability test of power devices, the test results obtained by the test method provided by the embodiment of the present application are single and reliable, providing a more reliable basis for the selection of power resistors and the design of converters.

[0009] In some embodiments, providing a periodic test voltage to the resistor under test includes: providing a first voltage to the resistor under test during a first time period of each cycle during the test; and stopping providing the first voltage to the resistor under test during a second time period of each cycle.

[0010] According to the above technical means, by setting a first time period in the test cycle to apply a first voltage and a second time period to stop power supply, the intermittent working state that the resistor may experience in actual use is simulated. This periodic power supply method can more comprehensively examine the performance changes of the resistor during the alternating process of power on and off, helping to discover potential problems that may occur when the resistor is frequently started and stopped, and improving the simulation accuracy of the test for the actual application scenario.

[0011] In some embodiments, the power supply assembly includes an adjustable power supply, which provides a periodic test voltage for the resistor under test, including: in the first time period, the adjustable power supply outputs the first voltage to the resistor under test; in the second time period, the adjustable power supply stops outputting the first voltage.

[0012] According to the above technical means, by utilizing the precise control characteristics of the adjustable power supply, the magnitude and start-stop time of the output voltage can be accurately adjusted, providing a stable and controllable voltage source for the test. This not only ensures the accuracy of the test voltage but also facilitates flexible adjustment of test parameters according to the requirements of different resistors under test, enhancing the versatility and adaptability of the test system.

[0013] In some embodiments, the power supply assembly includes an adjustable power supply and a contactor, which provides a periodic test voltage for the resistor under test, including: the adjustable power supply continuously outputs the first voltage; in the first time period, the contactor is turned on; in the second time period, the contactor is turned off.

[0014] According to the above technical means, when the power supply assembly includes an adjustable power supply and a contactor, the adjustable power supply continuously outputs the first voltage, and the contactor is turned on and off in the first and second time periods respectively. This design enables the adjustable power supply to avoid frequent start and stop, reducing the power consumption of the power supply itself and the impact on the power grid. At the same time, by controlling the circuit on and off through the contactor, periodic power supply can be achieved more quickly and reliably, improving the stability and reliability of the test process, especially suitable for test scenarios with high requirements for power supply stability.

[0015] In some embodiments, when the rated power consumption of the resistor under test is not greater than the first power consumption threshold, the first voltage is a DC voltage, and the peak-to-peak value of the ripple voltage of the DC voltage is not greater than 5%; when the rated power consumption of the resistor under test is greater than the first power consumption threshold, the first voltage is an AC voltage; the difference between the voltage value of the first voltage and the smaller value between the rated voltage and the limit voltage of the resistor under test is not greater than 5%.

[0016] According to the above technical means, by restricting the magnitude of the test voltage, it is ensured that the test voltage will neither be too high to cause the resistor to be damaged by excessive stress during the test and unable to accurately evaluate its normal durability, nor be too low to fail to fully stimulate the performance changes that the resistor may exhibit under near-actual working conditions. Thus, it is ensured that the test voltage can simulate the real working conditions and, at the same time, be within the reasonable range that the resistor can withstand, making the test results more reliable.

[0017] In some embodiments, determining a plurality of measured resistance values of the resistance under test at different measurement times during the test and the initial resistance value of the resistance under test includes: determining a plurality of measurement times according to the test requirements of the resistance under test; after the end of a second time period before each measurement time, placing the resistance under test under standard atmospheric pressure to recover for a third time; performing an appearance inspection on the resistance under test, and measuring the measured resistance value of the resistance under test when there is no visible damage and the markings are clear on the resistance under test; wherein the third time is greater than a first time threshold and less than a second time threshold.

[0018] According to the above technical means, a plurality of measurement times are determined based on the test requirements, and the resistance under test is allowed to recover for a third time under standard atmospheric pressure before measurement. This enables the resistance under test to have sufficient time to dissipate heat and return to a stable state, avoiding the influence of residual heat of the resistance or stress accumulation during the test on the accuracy of resistance value measurement. At the same time, the appearance inspection link can promptly detect whether there is visible damage to the resistance during the test, ensuring that the measured resistance value data truly reflects the performance of the resistance and improving the reliability of the test data.

[0019] In some embodiments, the method further includes: within a fourth time after measuring the measured resistance value of the resistance under test, placing the resistance under test into the test chamber.

[0020] According to the above technical means, the resistance is re-placed into the test chamber within the specified fourth time after measuring the resistance value, ensuring the coherence and consistency of the test environment. Preventing the resistance from being outside the test chamber for a long time, which may cause changes in conditions such as temperature and humidity and affect subsequent test results. Ensuring that the resistance is always in the simulated actual working condition environment is beneficial to more accurately evaluating the durability of the resistance under continuous working conditions and improving the effectiveness and credibility of the test results.

[0021] Second aspect, a power resistor durability test system is provided. The test system includes a power supply component, a resistor under test, a control unit, a test chamber, a collection unit, a host computer, and a measurement unit; the power supply component is connected to the resistor under test to form a test circuit; the resistor under test is located inside the test chamber; the collection unit is connected to the test chamber and the host computer for collecting temperature information of the test chamber; the control unit is connected to the test chamber, the power supply component, and the host computer; the host computer is configured to send control commands to the control unit according to the test requirements of the resistor under test; the control unit is configured to: adjust the temperature inside the test chamber according to the test requirements of the resistor under test so that the temperature inside the test chamber matches the test requirements; control the power supply component to provide a periodic test voltage to the resistor under test according to the rated power consumption of the resistor under test and the test requirements of the resistor under test; the measurement unit is configured to: determine a plurality of measured resistance values at different measurement times during the test of the resistor under test and the initial resistance value of the resistor under test; the host computer is further configured to: determine the durability test result of the resistor under test according to the change amount between the plurality of measured resistance values and the initial resistance value and a resistance value change amount threshold; wherein, the resistance value change amount threshold is related to the nominal resistance value of the resistor under test.

[0022] In some embodiments, the control unit is further configured to: control the power supply component to provide a first voltage to the resistor under test during a first time period of each cycle during the test; control the power supply component to stop providing the first voltage to the resistor under test during a second time period of each cycle.

[0023] In some embodiments, the power supply component includes an adjustable power supply, and the control unit is further configured to: control the adjustable power supply to output the first voltage to the resistor under test during the first time period; control the adjustable power supply to stop outputting the first voltage during the second time period.

[0024] In some embodiments, the power supply component includes an adjustable power supply and a contactor, and the control unit is further configured to: control the adjustable power supply to continuously output the first voltage, control the contactor to conduct during the first time period, and control the contactor to disconnect during the second time period.

[0025] In some embodiments, when the rated power consumption of the resistor under test is not greater than a first power consumption threshold, the first voltage is a DC voltage, and the peak-to-peak value of the ripple voltage of the DC voltage is not greater than 5%; when the rated power consumption of the resistor under test is greater than the first power consumption threshold, the first voltage is an AC voltage; the difference between the voltage value of the first voltage and the smaller value between the rated voltage and the limit voltage of the resistor under test is not greater than 5%.

[0026] In some embodiments, the measuring unit is further configured to: when the second time period before each measurement moment ends, the measured resistor is placed under standard atmospheric pressure to recover for a third time, and the measured resistor has no visible damage and clear markings, measure the actual resistance value of the measured resistor; wherein, the third time is greater than the first time threshold and less than the second time threshold.

[0027] In a third aspect, an electronic device is provided, including a processor and a memory, the memory is used to store a computer program, and the processor is used to execute the computer program to implement the method described in the first aspect.

[0028] In a fourth aspect, a chip is provided, including a processor, and the processor can be used to call and run a computer program from a memory, so that a device installed with the chip executes the method described in the first aspect.

[0029] In a fifth aspect, a computer-readable storage medium is provided, and the storage medium stores executable code, and when the executable code is executed, the method described in the first aspect is implemented.

[0030] In a sixth aspect, a computer program product is provided, the computer program product includes a program, the computer program product can be applied to the electronic device provided in the embodiments of the present application, and the program causes a computer to execute the method described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG. is a schematic diagram of a power resistor durability test system in the related art;

[0032] Figure 2 FIG. is a schematic diagram of another power resistor durability test system in the related art;

[0033] Figure 3 FIG. is a schematic flowchart of the power resistor durability test method provided in the embodiments of the present application;

[0034] Figure 4 FIG. is a schematic diagram of a test system applying the test method provided in the embodiments of the present application;

[0035] Figure 5 For Figure 3 FIG. is a flowchart of the method for determining multiple actual resistance values and initial values in the shown test method;

[0036] Figure 6 FIG. is a schematic diagram of a power resistor durability test system provided in the embodiments of the present application;

[0037] Figure 7Schematic diagram of the power resistor durability test system provided by another embodiment of the present application;

[0038] Figure 8 Schematic diagram of the power resistor durability test system provided by yet another embodiment of the present application;

[0039] Figure 9 Schematic structural diagram of the electronic device provided by the embodiment of the present application. Detailed implementation manners

[0040] The embodiment of the present application provides a power resistor durability test method and a test system. The technical solution of the present application will be further specifically described below through embodiments and in conjunction with the drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present application with reference to the drawings is intended to explain the overall concept of the present application and should not be construed as a limitation to the present application.

[0041] Before introducing the technical solution of the present application, a detailed example of the power resistor electrical durability test method in the related art and the problems thereof will be given.

[0042] With the in-depth development of rail transit electrification, vehicles such as locomotives and multiple units mostly use traction converters as the core devices of their power systems. There are multiple power resistors in the traction converter, such as charging resistors, overvoltage protection resistors, discharge resistors (fast discharge resistors and slow discharge resistors), and grounding resistors, etc. Due to the wide application of power resistors in the traction converter, the safety and reliability of their operation are very crucial.

[0043] For the manufacturers of traction converters, they often select and match power resistor devices through procurement, and their related testings are mostly carried out in the power resistor manufacturers, making it difficult to ensure that the power resistors in the same procurement batch meet the design requirements. Therefore, conducting electrical durability tests on the power resistors used in rail transit conversion devices is an important way to verify their effectiveness and reliability.

[0044] Figure 1Shown is a durability test system for a pre-charge resistor in the related art. The test system includes a high-voltage DC power supply, a low-voltage DC power supply, a vehicle controller, a multi-channel temperature rise recorder, a pre-charge resistor, a constant temperature chamber, a pre-charge contactor, a main contactor, a charging capacitor, an IGBT, a drive motor, and a motor controller. Among them, the positive pole of the high-voltage DC power supply, the pre-charge resistor, the pre-charge contactor, the charging capacitor, and the negative pole of the high-voltage DC power supply are connected in series in sequence to form a charging loop; the input end of the main contactor is connected to the input end of the pre-charge contactor, the output end of the main contactor is connected to the output end of the pre-charge contactor, and the drive motor is connected through the IGBT and the charging capacitor to form a discharging loop; both the vehicle controller and the pre-charge contactor are connected to the low-voltage DC power supply. Using this durability test system, the pre-charge resistor can be made as close as possible to the real working conditions.

[0045] Figure 2 Shown is a durability test device in another related art. The test device includes a high-voltage DC power supply, a charging relay, a freewheeling diode, a pre-charge resistor, a control unit, a collection unit, a discharging relay, a DC electronic load, a capacitor, a temperature test chamber, and a computer.

[0046] Figure 2 The test device in simulates the working environment of the pre-charge resistor in the vehicle, such as the ambient temperature of the pre-charge resistor in the vehicle, the working voltage used, etc. On this basis, when receiving a test request from the operator, the corresponding charge and discharge controls are executed in sequence to charge and discharge the test capacitor, and at the same time, the number of charge and discharge times is counted. When the cumulative value of the charge and discharge does not reach the preset durability threshold, the charge and discharge process is cyclically controlled. When the preset durability threshold is reached, the test stops.

[0047] The above two related technologies have realized the durability test of the electrical performance of the power resistor by building a durability test device. However, there are still some problems in the above two methods. Figure 1 The latter stage of the test system in uses the method of an inverter plus a drive motor, which will make the test platform complex. Figure 2 Although the test device in removes the main contactor and uses a DC electronic load as the discharging method; however, during the long-term continuous charge and discharge process, the capacitance value of the capacitor will also change, making it difficult to verify whether the change in the resistance value of the resistor or the attenuation of the capacitance value of the capacitor causes the influence in the durability test.

[0048] Both of the above related technologies are powered by direct current. This is because the latter stage of their electrical topologies uses support capacitors for charging and discharging. The disadvantage of this is that the durability test power supplies for different power resistors are divided into direct current and alternating current. In addition, it ignores the fact that the power resistor is originally an energy-consuming component, and there is no need to add an inverter + drive motor or a direct current electronic load for discharging in the test topology.

[0049] In summary, the power resistor durability test device in the related technology relies on the actual application circuit of the power resistor, has a complex structure, and the test results are easily affected by other components in the circuit, affecting the accuracy of the experimental results.

[0050] In view of the above problems, the embodiments of the present application provide a power resistor durability test method and a test system.

[0051] The test method and test system provided by the embodiments of the present application can be used for the durability test of various power resistors. The power resistors mentioned here can be, for example, charging resistors, overvoltage protection resistors, discharge resistors (including fast discharge resistors and slow discharge resistors), and grounding resistors, etc. The above-mentioned various types of power resistors can be power resistors applied to the rail converter device. By testing the durability, the number of operating times that can be operated without maintenance or replacement of parts can be determined. At the same time, the durability test is also the basis for life estimation. Through the durability test, technical support is provided for the selection of main devices of the converter, simplified design, cost control, health management, fault troubleshooting, etc.

[0052] Next, the technical solutions of the present application will be described in detail with reference to the accompanying drawings.

[0053] Figure 3 FIG. is a schematic flowchart of the power resistor durability test method provided by the embodiments of the present application. This method is applied to the durability test system. Therefore, before introducing this test method in detail, a brief description of this test system will be given first. Figure 4 FIG. is a schematic principle diagram of the test system 400 applying this test method.

[0054] Figure 4 The test system 400 in FIG. includes a power supply component 410, a resistor under test 420, a test chamber 430, and a collection unit 440.

[0055] Among them, the power supply component 410 is connected to the resistor under test 420 to form a test circuit, and this power supply component 410 can provide a test voltage for the resistor under test 420. The resistor under test 420 is located in the test chamber 430, and the collection unit 440 is connected to the test chamber 430 for collecting the temperature information of the test chamber 430.

[0056] It can be understood that in the power resistor test, the temperature in the test chamber 430 needs to be controlled within a certain range according to the test requirements. For example, for some resistors that work in a high-temperature environment, such as the resistors in an industrial motor control system, the temperature of the test chamber 430 can be set to 60 °C, and the resistor under test 420 can be subjected to a durability test in this simulated high-temperature environment to examine its performance in actual operation.

[0057] Therefore, in some embodiments of the present application, the test chamber 430 further includes a temperature control component, which can be, for example, a heating component such as an electric heating wire for heating.

[0058] The above acquisition unit 440 can be a temperature sensor, which can implement the acquisition of the ambient temperature in the test chamber 430. For example, the temperature sensor is installed inside the test chamber 430, and it will sense the temperature in the test chamber 430 in real time and convert the temperature signal into an electrical signal and transmit it to the data acquisition module. The data acquisition module then converts the electrical signal into a digital signal and transmits it to a computer through a serial port or a network interface, and the operator can view the temperature change in the test chamber 430 on the computer in real time.

[0059] Refer to Figure 3 , Figure 3 The method in

[0060] In step S310, according to the test requirements of the resistor under test, the temperature of the test chamber is adjusted so that the temperature in the test chamber matches the test requirements.

[0061] The test requirements of the resistor under test may include the test temperature, time, the change law of the test voltage, etc.

[0062] Taking the test temperature as an example, the test requirements can be determined according to different application scenarios and design requirements of the power resistor. Taking the power resistor applied to the rail transit traction converter mentioned above as an example. Rail transit vehicles may operate in different environments. For example, for high-speed railway trains or multiple unit trains operating in high-altitude or high-latitude regions, the power resistor may operate in a low-temperature environment for a long time. When testing it, the test conditions need to be set to match its operating environment, that is, the test temperature is set to be lower. Another example is that for vehicles operating in low-latitude regions, they may operate in a high-temperature environment for a long time. In this case, the test temperature needs to be set to be higher.

[0063] In the embodiments of the present application, the temperature of the test chamber can be adjusted according to the specific test requirements of the resistor under test to ensure that the test environment is as close as possible to the usage scenario, thereby improving the accuracy and reliability of the test results.

[0064] During the process of adjusting the temperature of the test chamber, the temperature acquisition unit can be used to obtain the temperature information of the test chamber in real time, and control the aforementioned temperature control component according to the current temperature of the test chamber, so that the real-time temperature of the test chamber meets the test requirements.

[0065] In step S320, according to the rated power consumption of the resistor under test and the test requirements of the resistor under test, the power supply component provides a periodic test voltage for the resistor under test.

[0066] Among them, the rated power consumption is the maximum power that the resistor under test can withstand under normal working conditions, and it is one of the important bases for determining the test voltage. The specific method of determining the test voltage according to the rated power consumption will be described in detail later.

[0067] Combining the rated power consumption and test requirements of the resistor under test, the power supply component provides a test voltage for the resistor under test according to a certain periodic law. The periodic test voltage can simulate the voltage change conditions that the resistor may encounter during actual use, and more comprehensively evaluate its durability.

[0068] For example, when testing a resistor with a rated power consumption of 2 watts and a nominal resistance value of 100 ohms, according to P = U 2 / R, the rated voltage of this resistor can be determined to be 14.14V. Assuming that the test requirement is to simulate the situation where the resistor alternately withstands the rated voltage and the general rated voltage every 10 minutes during actual use, then the power supply component will, according to this requirement, first output a voltage of 14.14V for 10 minutes, and then reduce the voltage to 7.07V and continue for 10 minutes, changing periodically in this way to test the durability of the resistor under different voltage conditions.

[0069] In step S330, determine multiple measured resistance values of the resistor under test at different measurement times during the test and the initial resistance value of the resistor under test.

[0070] The initial resistance value is the magnitude of the resistance value measured before the start of the test, and it is the reference value for subsequent evaluation of the resistance value change. During the test, according to the test requirements, the resistance value of the resistor under test is measured at different measurement times. These multiple measurement times can be related to the actual operating conditions of the resistor under test. For example, for a power resistor operating on a multiple unit train, it will stop working when the train stops at a station. Therefore, multiple measurement times can be determined according to the stopping rules of the train.

[0071] Taking the resistor with a rated power consumption of 2 watts and a nominal resistance value of 100 ohms in the previous text as an example, during the test, the adjacent measurement times can be set to 1 hour, that is, the resistance value of the resistor under test is measured with a multimeter every 1 hour. For example, when the test progresses to the 1st hour, the measured resistance value is 100.3 ohms; at the 2nd hour, the resistance value is 100.4 ohms; at the 3rd hour, the resistance value is 100.5 ohms. By recording the actual measured resistance values at these different measurement times, the change of the resistance value with time can be observed.

[0072] In step S340, according to the change amount between multiple actual measured resistance values and the initial resistance value and the resistance value change amount threshold, the durability test result of the resistor under test is determined.

[0073] Among them, the resistance value change amount refers to the difference between the aforementioned multiple resistance values and the initial resistance value, which reflects the change degree of the resistance value of the resistor under test during the test.

[0074] The resistance value change amount threshold is a preset standard value, which is related to the nominal resistance value of the resistor under test. The nominal resistance value is the design value of the resistor, and resistors with different nominal resistance values may have different resistance value change amount thresholds.

[0075] By comparing the resistance value change amount and the resistance value change amount threshold, if the resistance value change amount exceeds the threshold, it indicates that the resistor under test may have a performance decline or damage during the durability test, and the test result may be judged as unqualified; on the contrary, if the resistance value change amount does not exceed the threshold, it indicates that the resistor under test performs well during the test, and the durability test may be judged as qualified.

[0076] Taking the resistor with a nominal resistance value of 100 ohms mentioned above as an example, the resistance value change amount threshold can be set to ±5% of the nominal resistance value, that is, 100 * 5% = 5 ohms. When the test progresses to the 10th hour, the measured actual resistance value is 103 ohms, the initial resistance value is 100.2 ohms, and the resistance value change amount is 103 - 100.2 = 2.8 ohms. Since 2.8 ohms is less than the resistance value change amount threshold of 5 ohms, it indicates that the resistance value change of this resistor is within the allowable range during the 10-hour test, and the durability test result is initially judged as qualified. If the resistance value change amount exceeds 5 ohms in the subsequent test, it is determined that the durability test of this resistor is unqualified.

[0077] The following combines an example to further illustrate the method for determining the durability test result described above.

[0078] Taking the 1000h durability test of the RJ14 type (0.25W ± 5%) metal film resistor 510Ω as an example, Table 1 below shows the resistance values and the change amounts of the resistance values measured at multiple measurement times.

[0079] Table 1

[0080]

[0081]

[0082] The measured resistances 1 - 5 in the above table are the resistances measured at the 0th hour, 48th hour, 168th hour, 500th hour, and 1000th hour respectively.

[0083] For the above resistor, the threshold value of the resistance change amount is taken as (5%R + 0.1)Ω, that is, 25.6Ω. It can be seen from the above table that at multiple measurement times, the maximum value of the resistance change amount of the measured resistor is 11Ω (less than 25.6Ω). Therefore, it can be determined that the durability test of the measured resistor is qualified.

[0084] The technical solution of the embodiment of the present application constructs a durability test system that more conforms to the test requirements of the power resistor based on the characteristic that the essence of the power resistor is an energy-consuming component. When performing the durability test based on this test system, according to the test requirements of the measured resistor, parameters such as the temperature of the test chamber and the test voltage of the measured resistor during the test process are flexibly adjusted, which can meet the requirements of different test scenarios. Moreover, since this test system avoids the influence of other components in the actual application circuit on the durability test of the power device, the test results obtained according to the test method provided by the embodiment of the present application are single and reliable, providing a more reliable basis for the selection of power resistors and the design of converters.

[0085] In some embodiments, providing a periodic test voltage for the measured resistor as described above includes: providing a first voltage for the measured resistor in the first time period of each cycle during the test, and stopping providing the first voltage for the measured resistor in the second time period of each cycle. The test period mentioned here refers to the entire time range from the start of the durability test of the measured resistor to the end of the test, and this time range is usually defined by the test requirements.

[0086] The entire test period is divided into repeated time periods according to a certain time length, and each time period is a cycle. The first time period and the second time period are part of the time of each cycle and together constitute a complete cycle. For example, the above first time period can be 1.5 hours, and the second time period is 0.5 hours. That is, during the entire test stage, the voltage is applied periodically with 1.5 hours of power-on and 0.5 hours of power-off.

[0087] The above first voltage is a specific voltage value determined according to the rated power consumption of the resistor under test and the test requirements. For example, if the rated voltage of the resistor under test is 20V, according to the test requirements, we can set the first voltage to 20V. During the first time period of each cycle, the power supply component outputs this first voltage and applies it to the resistor under test, enabling the resistor to be in an operating state, with current passing through and power consumption occurring. During the second time period, the power supply component stops outputting the first voltage, which is equivalent to cutting off the power supply circuit of the resistor under test. At this time, no current passes through the resistor under test, no power consumption occurs, and it is in a stopped working state.

[0088] According to the above technical means, by setting a first time period within the test cycle to apply the first voltage and a second time period to stop power supply, the intermittent working state that the resistor may experience during actual use is simulated. This periodic power supply method can more comprehensively examine the performance changes of the resistor during the alternating process of power on and off, helping to discover potential problems that may occur under frequent start-stop conditions of the resistor and improving the simulation accuracy of the test for the actual application scenario.

[0089] In some embodiments, the power supply component includes an adjustable power supply, which provides a periodic test voltage for the resistor under test, including: during the first time period, the adjustable power supply outputs the first voltage to the resistor under test; during the second time period, the adjustable power supply stops outputting the first voltage.

[0090] An adjustable power supply is a power supply device whose output voltage can be adjusted according to needs. It can flexibly change the magnitude of the output voltage within a certain range to meet the test requirements of different resistors under test. For example, the output voltage of an adjustable DC power supply can be adjusted through a knob, buttons, or a digital control interface. By using an adjustable power supply, it is convenient to provide a suitable test voltage according to different test requirements. Through the intermittent operation of the adjustable power supply, intermittent power supply to the resistor under test is achieved.

[0091] According to the above technical means, by utilizing the precise control characteristics of the adjustable power supply, the magnitude and start-stop time of the output voltage can be accurately adjusted, providing a stable and controllable voltage source for the test. This not only ensures the accuracy of the test voltage but also facilitates flexible adjustment of test parameters according to the requirements of different resistors under test, enhancing the versatility and adaptability of the test system.

[0092] In some embodiments, the power supply component includes an adjustable power supply and a contactor, that is, the adjustable power supply, the contactor, and the resistor under test are connected in series to form a test circuit, which provides a periodic test voltage for the resistor under test, including: using the adjustable power supply to continuously output the first voltage; during the first time period, the contactor is turned on; during the second time period, the contactor is turned off.

[0093] According to the above technical means, when the power supply component includes an adjustable power supply and a contactor, the adjustable power supply continuously outputs a first voltage, and the contactor conducts and disconnects in the first and second time periods respectively. This design enables the adjustable power supply to avoid frequent start-stop, reducing the power loss of the power supply itself and the impact on the power grid. At the same time, by controlling the on-off of the circuit through the contactor, it can achieve periodic power supply more quickly and reliably, improving the stability and reliability of the test process, and is particularly suitable for test scenarios with high requirements for power supply stability.

[0094] In the embodiment of the present application, the aforementioned first voltage can be a DC voltage or an AC voltage, and the specific type of the first voltage can be related to the rated power consumption of the measured resistor.

[0095] Specifically, when the rated power consumption of the measured resistor is not greater than the first power consumption threshold, the first voltage is a DC voltage, and the peak-to-peak value of the ripple voltage of this DC voltage is not greater than 5%.

[0096] For resistors with a small rated power consumption, using a DC voltage for testing can more accurately simulate the DC electrical environment that the resistor bears in some actual application scenarios, making the test more targeted. The aforementioned rated power consumption can be 15W, for example.

[0097] The aforementioned ripple voltage refers to the AC component superimposed on the DC voltage, which reflects the fluctuation degree of the DC voltage. An excessive ripple voltage may cause the resistor to bear additional alternating stress during the test, resulting in inaccurate test results. Therefore, in the embodiment of the present application, the peak-to-peak value of the ripple voltage is limited to not greater than 5%, which can ensure a stable test voltage for the resistor, reduce the interference of voltage fluctuations on the test results, and improve the accuracy and reliability of the test results.

[0098] If the rated power consumption of the measured resistor exceeds the above first power consumption threshold, it means that this resistor may need to bear a relatively large power in actual applications. Therefore, in this case, an AC voltage is provided for testing. The test current at this time can more conform to the actual working conditions of this type of resistor, and can comprehensively detect the durability of the resistor under AC operating conditions.

[0099] In the embodiment of the present application, regardless of whether the first voltage is a DC voltage or an AC voltage, its voltage value needs to meet certain conditions, that is, compared with the smaller value of the rated voltage and the limit voltage of the measured resistor, the difference cannot exceed 5%. Among them, the rated voltage is the standard voltage at which the resistor can work normally for a long time, and the limit voltage is the maximum voltage that the resistor can withstand.

[0100] By restricting the magnitude of the test voltage, it is ensured that the test voltage is neither too high to cause the resistor to be damaged by excessive stress during the test and unable to accurately evaluate its normal durability, nor too low to fail to fully stimulate the performance changes that may occur in the resistor under near-actual working conditions. Thus, it is ensured that the test voltage can simulate the real working conditions and, at the same time, be within the reasonable range that the resistor can withstand, making the test results more reliable.

[0101] In some embodiments, as Figure 5 shown, the foregoing step S330, determining a plurality of measured resistance values of the resistor under test at different measurement times during the test and the initial resistance value of the resistor under test, further includes steps S331 - S333.

[0102] In step S331, according to the test requirements of the resistor under test, a plurality of measurement times are determined.

[0103] When performing the resistor durability test, different resistors may have different test requirements due to factors such as their application scenarios and performance requirements. According to these specific test requirements, a plurality of measurement times are reasonably planned. Taking the power resistor in the rail transit converter mentioned above as an example, a plurality of measurement times can be determined according to the operation law of the rail transit vehicle, and the interval between adjacent measurement times can be several hours or dozens of hours; for another example, for power resistors on equipment such as machine tools that operate for a long time, the measurement times of the power resistors thereon can be determined according to the equipment maintenance cycle; for another example, for power resistors in some general equipment, the measurement times can be determined according to the requirements of relevant national standards or industry standards. For example, in a 1000-hour durability test, the 48th hour, 168th hour, 500th hour, and 1000th hour of the test process are used as the measurement times.

[0104] In step S332, after the end of the second time period before each measurement time, the resistor under test is placed under standard atmospheric pressure to recover for a third time.

[0105] During the above test process, the resistor under test is in the environment of the test chamber, and the resistor may be in an unstable state due to changes in environmental temperature, humidity, and air pressure. Therefore, after the test proceeds to the measurement time, the resistor to be tested is taken out of the test chamber, or the environmental state of the test chamber is controlled so that the air pressure of the environment where the resistor is located is the standard atmospheric pressure, and it is placed in this state for a period of time to make the state of the resistor reach stability.

[0106] In the embodiments of the present application, the third time needs to meet the condition of being greater than the first time threshold and less than the second time threshold to ensure that the recovery time is sufficient for the resistor to reach a stable state and not too long to waste the test time.

[0107] In some embodiments, the first time threshold is 1 hour, and the second time threshold is 4 hours. At each measurement moment, the recovery time of the measured resistor is greater than 1 hour and less than 4 hours.

[0108] In step S333, perform an appearance inspection on the measured resistor. When there is no visible damage and the markings are clear, measure the actual resistance value of the measured resistor.

[0109] After the recovery for the aforementioned third time, when testing the resistor, first observe whether there are visible damages such as cracks, charring, and deformation on the resistor. If there are the above-mentioned visible damages on the resistor, its resistance value may have changed abnormally, and at this time, the measurement result will not accurately reflect the durability of the resistor in the normal state. Clear markings help to determine information such as the model and parameters of the resistor, ensuring the accuracy and traceability of the measurement.

[0110] According to the above technical means, determine multiple measurement moments based on the test requirements, and let the measured resistor recover for the third time under standard atmospheric pressure before measurement. This allows the measured resistor to have sufficient time to dissipate heat and return to a stable state, avoiding affecting the accuracy of the resistance value measurement due to the residual heat of the resistor or the stress accumulation during the test process. At the same time, the appearance inspection link can promptly detect whether there are visible damages to the resistor during the test, ensuring that the measured resistance value data truly reflects the performance of the resistor and improving the reliability of the test data.

[0111] In some embodiments, the foregoing method further includes: placing the measured resistor in a test chamber within a fourth time after measuring the measured resistor.

[0112] At each of the foregoing measurement moments, after the measured resistor is statically placed and the measurement is completed, it needs to be returned to the test state, that is, placed back in the test chamber. In the solution of the embodiment of the present application, the time difference between the measurement moment and the time when the measured resistor is re-placed in the test chamber is the fourth time, and the fourth time can be, for example, 12 hours.

[0113] According to the above technical means, re-place the resistor in the test chamber within the specified fourth time after measuring the resistance value, ensuring the coherence and consistency of the test environment. Preventing the resistor from being in the environment outside the test chamber for a long time from causing changes in conditions such as temperature and humidity, which may affect subsequent test results. Ensuring that the resistor is always in the simulated actual working condition environment is conducive to more accurately evaluating the durability of the resistor under continuous working conditions and improving the effectiveness and credibility of the test results.

[0114] The above combines Figures 1 - 5 and details the method embodiments of the present application. Next, the device embodiments of the present application will be described in detail with reference to the accompanying drawings. It can be understood that the description of the device embodiments corresponds to the description of the method embodiments in the foregoing text. Therefore, the parts not described in detail can refer to the foregoing device embodiments.

[0115] Figure 6 It is a schematic diagram of the power resistor durability test system provided by the embodiments of the present application. Figure 6 The test system 600 in it includes a power supply component 610, a resistor under test 620, a control unit 630, a test chamber 640, a collection unit 650, a host computer 660, and a measurement unit 670.

[0116] The power supply component 610 is connected to the resistor under test 620 to form a test circuit, which is used to provide a periodic test voltage to the resistor under test 620, so that the resistor under test 620 can work at a specific voltage. This periodic test voltage has been fully described and explained in the foregoing, and will not be elaborated here.

[0117] The resistor under test 620 is arranged in the test chamber 640. The test chamber 640 can provide a precisely controllable test environment for the resistor under test 620, and it can simulate different environmental conditions to test the durability of the resistor under various environments. For example, the temperature inside the test chamber 640 can be adjusted to different states such as high temperature, low temperature, or normal temperature.

[0118] The collection unit 650 is connected to the test chamber 640 and is used to collect the temperature information inside the test chamber 640. The collection unit 650 can be, for example, a temperature sensor.

[0119] The collection unit 650 is also connected to the host computer 660 to give feedback to the host computer 660 when the temperature information inside the test chamber 640 is collected, so that the host computer 660 can make subsequent decisions based on this temperature information.

[0120] It should be noted that the embodiments of the present application do not specifically limit the connection method between the collection unit 650 and the host computer 660. For example, the collection unit 650 can be wired to the host computer 660 through a communication cable, or the collection unit 650 can be connected to the host computer 660 by means of wireless communication.

[0121] The control unit 630 is connected to the test chamber 640, the power supply component 610, and the host computer 660. It can receive the control commands of the host computer 660 to adjust and control the temperature of the test chamber 640 and the output voltage of the power supply component 610. More specifically, the control unit 630 can adjust the temperature inside the test chamber 640 according to the test requirements of the resistor under test 620 to make the temperature inside the test chamber 640 match the test requirements; and, according to the rated power consumption of the resistor under test 620 and the test requirements of the resistor under test 620, control the power supply component 610 to provide a periodic test voltage to the resistor under test 620.

[0122] The measuring unit 670 is used to measure multiple measured resistance values and the initial resistance value of the resistance under test 620 at different measurement times during the test process. The measuring unit 670 can be a multimeter or a dedicated resistance measuring instrument.

[0123] It should also be noted that in the embodiments of the present application, there are no limitations on the connection manners between the control unit 630 and the test chamber 640, the power supply assembly 610, and the upper computer 660, nor on the connection manner between the measuring unit 670 and the upper computer 660. The two interconnected units or components can be connected by wired or wireless means.

[0124] The upper computer 660 is the decision-making center of the entire test system, capable of generating and sending the aforementioned control commands based on the test requirements of the resistance under test 620, and at the same time, capable of determining the test result of the resistance under test 620 according to the resistance value data provided by the measuring unit 670 in combination with the resistance value change threshold. Among them, the resistance value change threshold is related to the nominal resistance value of the resistance under test 620.

[0125] Based on the characteristic that the essence of the power resistor in the above embodiments of the present application is an energy-consuming component, a durability test platform that more meets the test requirements of the power resistor is constructed, rather than an experimental environment that simulates the actual working conditions of the power. Compared with the technical solutions in the related art, this test system cancels the discharge link, greatly simplifies the experimental platform. Secondly, because only the power resistor is charged and discharged, and the actual circuit of the power resistor does not need to be built, the requirements for the power supply are reduced. In addition, this test system avoids the influence of other components in the actual application circuit on the durability test of the power device, making the test result single and reliable. When applied to the rail transit converter, it provides a more reliable basis for the selection of the power resistor and the design of the converter.

[0126] In some embodiments, the above control unit 630 is further configured to: control the power supply assembly 610 to provide a first voltage to the resistance under test 620 during the first time period of each cycle during the test; and control the power supply assembly 610 to stop providing the first voltage to the resistance under test 620 during the second time period of each cycle.

[0127] It can be understood that during the entire test period, the test time is divided into multiple cycles, each cycle includes a first time period and a second time period, power is supplied during the first time period, and power is cut off during the second time period, so that the power supply assembly 610 intermittently provides a test voltage to the resistance under test 620 to more realistically simulate the working mode of the resistance in actual application and improve the authenticity and effectiveness of the test.

[0128] It should be noted that in the embodiments of the present application, the time of each cycle, as well as the lengths of the first time period and the second time period within each cycle, are not specifically limited. As an example, the time length of each cycle is 2 hours. Within each cycle, the first time period is 1.5 hours and the second time period is 0.5 hours. That is to say, the power supply component 610 will periodically provide a test voltage to the resistance under test 620 in a manner of supplying power for 1.5 hours and powering off for 0.5 hours.

[0129] In some embodiments, as Figure 7 shown, the power supply component 610 includes an adjustable power supply 611. The control unit 630 is further configured to: during the first time period, control the adjustable power supply to output a first voltage to the resistance under test; during the second time period, control the adjustable power supply to stop providing the first voltage to the resistance under test.

[0130] In the embodiments of the present application, since the adjustable power supply can flexibly adjust the output voltage, it can more precisely meet the test requirements of different resistances under test, thereby improving the flexibility and adaptability of the test.

[0131] In some embodiments, as Figure 8 shown, the power supply component 610 includes an adjustable power supply 612 and a contactor 613. The control unit 630 is further configured to: control the adjustable power supply 612 to continuously output a first voltage, control the contactor 613 to conduct during the first time period, and control the contactor 613 to disconnect during the second time period.

[0132] Different from Figure 7 the implementation shown in, in this embodiment, through the on / off control of the contactor, the periodic power supply to the resistance under test can be realized more quickly and reliably, reducing the possible damage risk caused by the frequent start and stop of the power supply component, and simplifying the complexity of the power supply control.

[0133] In some embodiments, when the rated power consumption of the resistance under test is not greater than the first power consumption threshold, the first voltage is a DC voltage, and the peak-to-peak value of the ripple voltage of the DC voltage is not greater than 5%; when the rated power consumption of the resistance under test is greater than the first power consumption threshold, the first voltage is an AC voltage; the difference between the voltage value of the first voltage and the smaller value between the rated voltage and the limit voltage of the resistance under test is not greater than 5%.

[0134] In some embodiments, the aforementioned measuring unit 670 is further configured to: at the end of the second time period before each measurement moment, when the resistance under test is placed under standard atmospheric pressure and restored for a third time, and the resistance under test has no visible damage and the markings are clear, measure the measured resistance value of the resistance under test; where the third time is greater than the first time threshold and less than the second time threshold. The third time, the first time threshold, and the second time threshold have all been described in detail in the method embodiments above and will not be elaborated here.

[0135] The embodiments of the present application also provide an electronic device. Figure 9 It is a schematic structural diagram of the electronic device 900. Figure 9 The dotted line in it indicates that the unit or module is optional. The electronic device is used to implement the method described in the above method embodiments, or, for example, the electronic device can be a control device of a test system or a test device applying the test method described above.

[0136] Figure 9 The electronic device 900 in it may include one or more processors 910. The processor 910 can support the electronic device 900 to implement the method described in the above method embodiments. The processor 910 can be a general-purpose processor or a dedicated processor. For example, the processor can be a central processing unit (CPU). Alternatively, the processor 910 can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0137] The electronic device 900 may also include one or more memories 920. A program is stored on the memory 920, and the program can be executed by the processor 910, so that the processor 910 executes the method described in the above method embodiments. The memory 920 can be independent of the processor 910 or integrated in the processor 910.

[0138] The electronic device 900 may also include a transceiver 930. The processor 910 can communicate with other devices or chips through the transceiver 930. For example, the processor 910 can send and receive data with other devices or chips through the transceiver 930.

[0139] The embodiments of the application also provide a chip, including a processor, which can be used to call and run a computer program from a memory, so that a device installed with the chip executes the method described in the above method embodiments. It can be understood that the processor can be any type of processor mentioned above. It can be understood that the memory can be independent of the chip or integrated in the chip.

[0140] An embodiment of the present application also provides a computer-readable storage medium. The storage medium stores executable code, and when the executable code is executed, the method described in any of the foregoing embodiments is implemented.

[0141] An embodiment of the present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to the electronic device provided in the embodiment of the present application, and the program enables the computer to execute the methods in various embodiments of the present application.

[0142] It should be understood that the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0143] In various embodiments of the present application, the order numbers of the above processes do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0144] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0145] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0146] In addition, in each embodiment of the present application, the functional units can be integrated in one processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0147] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired manner (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a digital video disc (DVD)), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0148] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A power resistor durability test method, characterized in that: The method is applied to a durability test system, the test system comprising a power supply component, a resistor to be measured, a test box and a temperature acquisition unit, the power supply component is connected with the resistor to be measured to form a test loop, the resistor to be measured is located in the test box, the acquisition unit is connected with the test box, and is used to collect temperature information of the test box; the method comprises: According to the test requirements of the measured resistor, the temperature of the test box is adjusted so that the temperature in the test box matches the test requirements; According to the rated power consumption of the resistor under test and the test requirements of the resistor under test, using the power supply component to provide a periodic test voltage for the resistor under test; Determining a plurality of measured resistance values ​​of the measured resistor at different measurement times of the test and an initial resistance value of the measured resistor; The durability test result of the measured resistor is determined according to the change between the multiple measured resistance values ​​and the initial resistance value and the resistance change threshold; wherein the resistance change threshold is related to the nominal resistance of the measured resistor.

2. The method according to claim 1, characterized in that The step of providing a periodic test voltage to the resistor under test comprises: In a first time period of each cycle during the test, providing a first voltage to the resistor under test; In the second time period of each cycle, the first voltage is stopped from being provided to the resistor under test.

3. The method according to claim 2, characterized in that The power supply assembly includes an adjustable power supply, and the periodic test voltage provided to the measured resistor includes: In the first time period, the adjustable power supply outputs the first voltage to the measured resistor; During the second time period, the adjustable power supply stops outputting the first voltage.

4. The method according to claim 2, characterized in that: The power supply assembly includes an adjustable power supply and a contactor, and the periodic test voltage is provided for the measured resistor, including: The adjustable power supply continuously outputs the first voltage; During the first time period, the contactor is turned on; During the second time period, the contactor is open.

5. The method according to any one of claims 2 to 4, characterized in that: When the rated power consumption of the measured resistor is not greater than the first power consumption threshold, the first voltage is a DC voltage, and the peak-to-peak value of the ripple voltage of the DC voltage is not greater than 5%; When the rated power consumption of the measured resistor is greater than the first power consumption threshold, the first voltage is an AC voltage; The difference between the voltage value of the first voltage and the smaller value between the rated voltage of the measured resistor and the limit voltage of the measured resistor is not greater than 5%.

6. The method according to claim 1, characterized in that Therefore, determining a plurality of measured resistance values ​​of the measured resistor at different measurement times of the test and the initial resistance value of the measured resistor includes: Determining multiple measurement times according to the test requirements of the measured resistor; After the second time period before each measurement moment ends, placing the measured resistor under standard atmospheric pressure to recover for a third time; Performing a visual inspection on the resistor to be measured, and measuring the actual resistance value of the resistor to be measured when the resistor to be measured has no visible damage and is clearly marked; The third time is greater than the first time threshold and less than the second time threshold.

7. The method according to claim 6, characterized in that The method further comprises: Within a fourth time after measuring the actual resistance value of the resistor to be measured, the resistor to be measured is placed in the test box.

8. A power resistor durability test system, characterized in that: The test system includes a power supply component, a resistance to be measured, a control unit, a test box, a collection unit, a host computer and a measurement unit; The power supply component is connected to the resistor to be measured to form a test loop; The measured resistance is located in the test box; The acquisition unit is connected to the test box and the host computer, and is used to collect temperature information of the test box; The control unit is connected to the test box, the power supply assembly and the host computer; The host computer is used to send a control command to the control unit according to the test requirements of the measured resistor; The control unit is used to: adjust the temperature in the test box according to the test requirements of the measured resistor so that the temperature in the test box matches the test requirements; and control the power supply component to provide a periodic test voltage for the measured resistor according to the rated power consumption of the measured resistor and the test requirements of the measured resistor; The measuring unit is used to: determine a plurality of measured resistance values ​​at different measurement moments of the measured resistance test and an initial resistance value of the measured resistance; The host computer is also used to: determine the durability test result of the measured resistor according to the change amount between the multiple measured resistance values ​​and the initial resistance value and the resistance change amount threshold; The resistance change threshold is related to the nominal resistance of the resistor being measured.

9. The test system according to claim 8, characterized in that: The control unit is also used for: In a first time period of each cycle during the test, the power supply component is controlled to provide a first voltage to the resistor under test; in a second time period of each cycle, the power supply component is controlled to stop providing the first voltage to the resistor under test.

10. The test system according to claim 9, characterized in that: The power supply assembly includes an adjustable power supply, and the control unit is further used for: In the first time period, controlling the adjustable power supply to output the first voltage to the measured resistor; In the second time period, the adjustable power supply is controlled to stop outputting the first voltage.

11. The test system according to claim 9, characterized in that: The power supply assembly includes an adjustable power supply and a contactor, and the control unit is further used for: The adjustable power supply is controlled to continuously output the first voltage, the contactor is controlled to be turned on during the first time period, and the contactor is controlled to be turned off during the second time period.

12. The test system according to any one of claims 9 to 11, characterized in that: When the rated power consumption of the measured resistor is not greater than the first power consumption threshold, the first voltage is a DC voltage, and the peak-to-peak value of the ripple voltage of the DC voltage is not greater than 5%; When the rated power consumption of the measured resistor is greater than the first power consumption threshold, the first voltage is an AC voltage; The difference between the voltage value of the first voltage and the smaller value between the rated voltage of the measured resistor and the limit voltage of the measured resistor is not greater than 5%.

13. The test system according to any one of claims 8 to 11, characterized in that: The measuring unit is also used for: At the end of the second time period before each measurement moment, the measured resistor is placed under standard atmospheric pressure to recover for a third time, and when the measured resistor has no visible damage and is clearly marked, the actual resistance value of the measured resistor is measured; The third time is greater than the first time threshold and less than the second time threshold.

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