Frequency conversion series resonance withstand voltage test system and device

Abstract

The invention relates to the technical field of variable-frequency series resonance voltage withstanding tests, and particularly discloses a variable-frequency series resonance voltage withstanding test system and a variable-frequency series resonance voltage withstanding test device. Comprising a theoretical resonant frequency calculation module, an output frequency information acquisition module, a test resonant frequency evaluation module, a voltage withstanding test information acquisition module, a voltage withstanding performance stability analysis module and a power cable insulation performance evaluation module. According to the method, the resonant frequency accuracy of a series resonant circuit in a complete resonant state is deeply analyzed, and the voltage-withstanding stability and the insulation performance of the power cable are analyzed by combining the voltage condition, the leakage current condition, the temperature condition and the partial discharge condition of the power cable in a voltage-withstanding test; and meanwhile, the coverage of voltage-withstanding stability evaluation of the power cable is improved, so that the persuasion of the insulation performance of the power cable to unqualified evaluation is improved, and a more targeted basis is provided for maintenance and repair of the power cable.

Description

Technical Field

[0001] The present invention relates to the technical field of variable frequency series resonance withstand voltage test, and in particular to a variable frequency series resonance withstand voltage test system and device. Background Art

[0002] In the operation and maintenance of the power system, it is very important to ensure that the insulation performance of the power cable is good. There are many disadvantages in the traditional method of conducting voltage withstand tests on power cables. On the one hand, the required power capacity is extremely large, and it is often difficult to meet such high power supply requirements on site, resulting in the inability to carry out the test smoothly. On the other hand, traditional test equipment is large and bulky, and transportation and on-site layout are extremely inconvenient, consuming a lot of manpower, material resources and time costs. Therefore, it is urgent to develop an efficient, convenient and accurate voltage withstand test system and device.

[0003] For example, the Chinese patent publication number CN103869113B discloses a high-voltage series resonance device and a withstand voltage test method using the device, including: a variable frequency power supply cabinet, a test transformer, a resonant reactor and a test voltage measuring device with a current sensor, wherein the current sensor is connected in series between the tail of the high-voltage end of the test transformer and the grounding end of the capacitive test product. The resonant reactor has a fixed number of sections and is installed in a fixed position so that the inductance of the resonant reactor remains unchanged. The device is used to adjust the frequency of the output voltage signal of the variable frequency power supply cabinet so that when the series resonant circuit is in a fully resonant state, the voltage values ​​at both ends of the resonant reactor and the test product are equal, and the detected test voltage of the test product is determined after Fourier transformation. This method does not require the configuration of a high-voltage voltage divider specifically for measuring the test voltage, thereby achieving efficient, safe and convenient completion of the withstand voltage test, and can ensure that the test voltage accuracy is within the allowable range, greatly improving the safety and work efficiency of the high-voltage series resonant AC withstand voltage test.

[0004] The following problems still exist in the prior art: 1. Currently, we only focus on whether the series resonant circuit is in a fully resonant state, and do not conduct an in-depth analysis of the accuracy of the resonant frequency of the series resonant circuit when it is in a fully resonant state, which reduces the accuracy of the resonant frequency confirmation and the accuracy of the subsequent withstand voltage test results, which has an adverse effect on the subsequent insulation performance evaluation of the power cable.

[0005] 2. The voltage conditions, leakage current conditions, temperature conditions and partial discharge conditions of the power cables in the voltage withstand test are not combined to analyze whether the voltage withstand stability and insulation performance of the power cables are qualified or not, which reduces the coverage of the voltage withstand stability evaluation of the power cables, thereby reducing the persuasiveness of the insulation performance evaluation of the power cables. At the same time, it is unable to provide a more targeted basis for the maintenance and repair of the power cables, reducing the reliability and safety of the power cable operation. Summary of the invention

[0006] In view of this, in order to solve the problems raised in the above background technology, a variable frequency series resonance withstand voltage test system and device are now proposed.

[0007] The purpose of the present invention can be achieved through the following technical solutions: In the first aspect, the present invention provides a variable frequency series resonant voltage withstand test system, including: a theoretical resonant frequency calculation module, used to extract the capacitance value of the target power cable and the inductance value of the target inductor in the voltage withstand test, and calculate the theoretical resonant frequency of the target power cable.

[0008] The output frequency information acquisition module is used to slowly increase the output frequency of the target variable frequency power supply in the withstand voltage test, collect the current value corresponding to the target test circuit at each output frequency in the withstand voltage test, and simultaneously collect the voltage value at both ends of the target power cable at each output frequency.

[0009] The test resonant frequency evaluation module is used to evaluate whether the test resonant frequency of the target power cable in the voltage withstand test is accurate. If it is accurate, the voltage withstand test information acquisition module is executed. If it is inaccurate, it indicates that the voltage withstand test cannot continue and feedback is given.

[0010] The voltage withstand test information acquisition module is used to keep the test resonant frequency unchanged during the voltage withstand test, set the test voltage of the target power cable during the voltage withstand test, extract the reasonable range of leakage current of the target power cable, and collect the number of discharges of each cable section in the target power cable during the voltage withstand test, the discharge amount corresponding to each discharge, the cable temperature, and the voltage and leakage current corresponding to each monitoring time point.

[0011] The voltage withstand performance stability analysis module is used to analyze the voltage withstand performance stability of each cable segment in the target power cable during the voltage withstand test.

[0012] The power cable insulation performance evaluation module is used to evaluate whether the insulation performance of the target power cable is qualified, and provide feedback if it is unqualified.

[0013] The second aspect of the present invention provides a device, which includes a processor, a memory and a communication bus. The memory stores a computer-readable program that can be executed by the processor. The communication bus realizes the connection and communication between the processor and the memory. When the processor executes the computer-readable program, the variable frequency series resonance withstand voltage test system is realized.

[0014] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: (1) By adopting the variable frequency series resonance method, the present invention can realize high voltage testing of cables at a lower power capacity compared with traditional withstand voltage test methods (such as directly using a high voltage test transformer). This is because in the resonant state, the reactive power in the circuit is mainly exchanged between the reactor and the cable capacitor, and the power supply only needs to provide the active power part in the circuit, which greatly reduces the requirements for the test power supply capacity. It can be applied to on-site testing of large-capacity cables, reduces the volume and weight of the test equipment, and improves the convenience of the test.

[0015] (2) The present invention improves the accuracy of resonant frequency confirmation by conducting an in-depth analysis of the resonant frequency accuracy of the series resonant circuit when it is in a fully resonant state, while also improving the accuracy of subsequent withstand voltage test results, thereby avoiding adverse effects on subsequent insulation performance evaluation of the power cable.

[0016] (3) The present invention analyzes the withstand voltage stability and insulation performance of the power cable in combination with the voltage conditions, leakage current conditions, temperature conditions and partial discharge conditions of the power cable in the withstand voltage test, thereby improving the coverage of the withstand voltage stability evaluation of the power cable, thereby improving the persuasiveness of the insulation performance evaluation of the power cable, and at the same time providing a more targeted basis for the maintenance and repair of the power cable, thereby improving the reliability and safety of the power cable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the system module structure connection of the present invention.

[0019] Figure 2 The figure is a schematic diagram of the structure of a device of the present invention.

[0020] Figure 3 This is a flow chart of the resonant frequency accuracy evaluation test of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] See also Figure 1 As shown, the present invention provides a variable frequency series resonant voltage withstand test system, including: a theoretical resonant frequency calculation module, an output frequency information acquisition module, a test resonant frequency evaluation module, a voltage withstand test information acquisition module, a voltage withstand performance stability analysis module and a power cable insulation performance evaluation module.

[0023] The theoretical resonant frequency calculation module and the output frequency information acquisition module are both connected to the experimental resonant frequency evaluation module, the experimental resonant frequency evaluation module is connected to the voltage test information acquisition module, the voltage test information acquisition module is connected to the voltage performance stability analysis module, and the voltage performance stability analysis module is connected to the power cable insulation performance evaluation module.

[0024] The theoretical resonant frequency calculation module is used to extract the capacitance value of the target power cable and the inductance value of the target reactor in the withstand voltage test, and calculate the theoretical resonant frequency of the target power cable.

[0025] It should be noted that the capacitance value of the target power cable is extracted from the product manual provided by the target power cable manufacturer, and the inductance value of the target reactor in the withstand voltage test is extracted from the nameplate of the target reactor itself.

[0026] In a specific embodiment of the present invention, the method of calculating the theoretical resonant frequency of the target power cable is: the capacitance value of the target power cable and the inductance value of the target reactor in the withstand voltage test are recorded as C and L respectively.

[0027] Calculate the theoretical resonant frequency f of the target power cable 理 ,

[0028] The output frequency information acquisition module is used to slowly increase the output frequency of the target variable frequency power supply in the withstand voltage test, collect the current value corresponding to the target test circuit at each output frequency in the withstand voltage test, and simultaneously collect the voltage value at both ends of the target power cable at each output frequency.

[0029] It should be noted that in the withstand voltage test, the current value corresponding to the target circuit at each output frequency is collected by a current transformer, and the voltage value at both ends of the target power cable at each output frequency is measured by a capacitive voltage divider.

[0030] The test resonant frequency evaluation module is used to evaluate whether the test resonant frequency of the target power cable in the voltage withstand test is accurate. If it is accurate, the voltage withstand test information acquisition module is executed. If it is inaccurate, it indicates that the voltage withstand test cannot continue and feedback is provided.

[0031] In a specific embodiment of the present invention, the specific process of evaluating whether the test resonant frequency of the target power cable in the voltage withstand test is accurate is: using the output frequency as the horizontal coordinate and the current value as the vertical coordinate, constructing the current-frequency curve in the voltage withstand test, and locating the output frequency corresponding to the maximum current value from the curve, and recording it as the first output frequency.

[0032] The voltage-frequency curve in the withstand voltage test is constructed with the output frequency as the horizontal coordinate and the voltage value at both ends as the vertical coordinate, and the output frequency corresponding to the voltage peak is located from the curve and recorded as the second output frequency.

[0033] Calculate the test resonant frequency accuracy β of the target power cable in the voltage withstand test.

[0034] In a specific embodiment of the present invention, the specific process of calculating the test resonant frequency accuracy of the target power cable in the withstand voltage test is: subtracting the theoretical resonant frequency of the target power cable from the first output frequency to obtain an output frequency deviation between the theoretical resonant frequency and the first output frequency, and recording it as △f1.

[0035] The theoretical resonant frequency of the target power cable is subtracted from the second output frequency to obtain an output frequency deviation between the theoretical resonant frequency and the second output frequency, which is recorded as Δf2.

[0036] The first output frequency is subtracted from the second output frequency to obtain an output frequency deviation between the first output frequency and the second output frequency, which is recorded as Δf3.

[0037] Calculate the test resonant frequency accuracy β of the target power cable in the withstand voltage test, Here, Δf represents the output frequency deviation allowed by the setting, and e represents a natural constant.

[0038] See also Figure 3 As shown, the test resonant frequency accuracy of the target power cable in the voltage withstand test is compared with the resonant frequency accuracy of the set reference. If the test resonant frequency accuracy of the target power cable in the voltage withstand test is greater than or equal to the resonant frequency accuracy of the set reference, it indicates that the test resonant frequency of the target power cable in the voltage withstand test is accurate. Otherwise, it indicates that the test resonant frequency of the target power cable in the voltage withstand test is inaccurate.

[0039] The embodiment of the present invention improves the accuracy of resonant frequency confirmation by performing an in-depth analysis on the resonant frequency accuracy of the series resonant circuit in a fully resonant state, while also improving the accuracy of subsequent withstand voltage test results, thereby avoiding adverse effects on subsequent insulation performance evaluation of the power cable.

[0040] The voltage withstand test information acquisition module is used to keep the test resonant frequency in the voltage withstand test unchanged, set the test voltage of the target power cable in the voltage withstand test, extract the reasonable range of leakage current of the target power cable, and collect the number of discharges of each cable section in the target power cable in the voltage withstand test, the discharge amount corresponding to each discharge, the cable temperature, and the voltage and leakage current corresponding to each monitoring time point.

[0041] It should be noted that the test voltage of the target power cable in the withstand voltage test is set as follows: the test voltage value is determined according to the rated voltage of the target power cable and relevant standards. For example, for a 110kV cable, the test voltage may be 1.7 times the rated voltage (ie 187kV).

[0042] It should also be noted that the reasonable range of leakage current of the target power cable is extracted from the product manual provided by the target power cable manufacturer, the number of discharges of each cable segment in the target power cable in the voltage withstand test and the discharge amount corresponding to each discharge are collected by the installed partial discharge detector, the cable temperature of each cable segment in the target power cable in the voltage withstand test is measured by an infrared thermal imager, and the voltage and leakage current corresponding to each monitoring time point of each cable segment in the target power cable in the voltage withstand test are respectively measured by a voltmeter and a microammeter connected in series in the test circuit.

[0043] The voltage withstand performance stability analysis module is used to analyze the voltage withstand performance stability of each cable segment in the target power cable during the voltage withstand test.

[0044] In a specific embodiment of the present invention, the specific process of analyzing the voltage stability of each cable segment in the target power cable in the voltage test is as follows: based on the number of discharges of each cable segment in the target power cable in the voltage test, the discharge amount corresponding to each discharge, the cable temperature, and the voltage and leakage current corresponding to each monitoring time point, the voltage stability x of each cable segment in the target power cable in the voltage test is calculated respectively. i 、Leakage current reasonableness δ i , Partial discharge abnormality index and temperature anomaly index θ i , where i represents the number of the cable segment, i=1,2,...,n.

[0045] In a specific embodiment of the present invention, the specific process of calculating the voltage stability of each cable segment in the target power cable in the voltage withstand test is as follows: subtract the voltage corresponding to each monitoring time point of each cable segment in the target power cable in the voltage withstand test from the test voltage of the target power cable in the voltage withstand test to obtain the voltage deviation corresponding to each monitoring time point of each cable segment in the target power cable in the voltage withstand test, and compare it with the voltage deviation set as a reference for the corresponding cable segment; if the voltage deviation corresponding to a certain monitoring time point in the voltage withstand test of a cable segment is greater than or equal to the voltage deviation set as a reference for the cable segment, then the monitoring time point is recorded as an abnormal time point, and the number of abnormal time points of each cable segment in the target power cable in the voltage withstand test is counted and recorded as ε i .

[0046] Calculate the voltage stability x of each cable section in the target power cable during the withstand voltage test i , Among them, ε′ represents the number of abnormal time points set as reference.

[0047] In a specific embodiment of the present invention, the specific process of calculating the reasonableness of the leakage current of each cable segment in the target power cable in the withstand voltage test is: comparing the leakage current corresponding to each monitoring time point of each cable segment in the target power cable in the withstand voltage test with the reasonable range of the leakage current of the target power cable; if the leakage current corresponding to each monitoring time point of a cable segment in the target power cable in the withstand voltage test is within the reasonable range of the leakage current, the reasonableness of the leakage current of the cable segment in the withstand voltage test is recorded as τ1.

[0048] If the leakage current corresponding to the monitoring time point of a certain cable section in the target power cable during the voltage withstand test is not within the reasonable range of the leakage current, the reasonableness of the leakage current of the cable section during the voltage withstand test is recorded as τ2.

[0049] If the leakage current corresponding to each monitoring time point of a cable section in the target power cable during the voltage withstand test is not within the reasonable range of the leakage current, the reasonableness of the leakage current of the cable section during the voltage withstand test is recorded as τ3.

[0050] In summary, the reasonableness of leakage current δ of each cable section in the target power cable during the withstand voltage test is obtained: i , δ i The value of is τ1 or τ2 or τ3, where τ1>τ2>τ3.

[0051] In a specific embodiment of the present invention, the setting value of τ1 is 1, and the setting value of τ2 is The setting value of τ3 is 0.

[0052] In a specific embodiment of the present invention, the specific process of calculating the partial discharge abnormality index of each cable segment in the target power cable during the withstand voltage test is as follows: the number of discharges of each cable segment in the target power cable during the withstand voltage test is recorded as μ i .

[0053] The discharge amount corresponding to each discharge of each cable segment in the target power cable during the withstand voltage test is accumulated to obtain the total discharge amount of each cable segment in the target power cable during the withstand voltage test, which is recorded as Q i .

[0054] Calculate the partial discharge anomaly index of each cable section in the target power cable during the withstand voltage test Here, μ′ and Q′ represent the discharge number and discharge amount of the set reference, respectively.

[0055] It should be noted that the specific process of calculating the temperature anomaly index of each cable segment in the target power cable in the voltage withstand test is: comparing the cable temperature of each cable segment in the target power cable in the voltage withstand test with the set reference normal cable temperature range; if the cable temperature of a cable segment in the target power cable in the voltage withstand test is within the set reference normal cable temperature range, then the temperature anomaly index of the cable segment in the voltage withstand test is recorded as σ1.

[0056] If the cable temperature of a cable section in the target power cable during the voltage withstand test is not within the set reference normal cable temperature range, the temperature anomaly index of the cable section during the voltage withstand test is recorded as σ2.

[0057] In summary, the temperature anomaly index θ of each cable segment in the target power cable during the withstand voltage test is obtained: i ,θ i The value of is σ1 or σ2, where σ1<σ2.

[0058] In a specific embodiment of the present invention, the set value of σ1 is 0, and the set value of σ2 is 1.

[0059] Calculate the voltage withstand performance stability of each cable segment in the target power cable during the voltage withstand test Among them, a1, a2, a3 and a4 respectively represent the weights of the set voltage stability, leakage current rationality, partial discharge abnormality index and temperature abnormality index corresponding to the withstand voltage performance stability assessment, a1+a2+a3+a4=1.

[0060] In a specific embodiment of the present invention, the setting value of a1 is 0.25, the setting value of a2 is 0.25, the setting value of a3 is 0.25, and the setting value of a4 is 0.25. When calculating the voltage withstand performance stability of each cable section of the target power cable in the voltage withstand test, voltage stability, leakage current rationality, partial discharge anomaly index and temperature anomaly index are all very important factors, which reflect the voltage withstand performance of the cable from different aspects.

[0061] The power cable insulation performance evaluation module is used to evaluate whether the insulation performance of the target power cable is qualified, and to provide feedback if it is unqualified.

[0062] In a specific embodiment of the present invention, the specific process of evaluating whether the insulation performance of the target power cable is qualified is: calculating the insulation performance qualification ξ of the target power cable, in, It indicates the stability of the withstand voltage performance of the set reference, and n indicates the number of cable segments.

[0063] The insulation performance qualification of the target power cable is compared with the insulation performance qualification of the set reference. If the insulation performance qualification of the target power cable is less than the insulation performance qualification of the set reference, it indicates that the insulation performance of the target power cable is unqualified. Otherwise, it indicates that the insulation performance of the target power cable is qualified.

[0064] The embodiments of the present invention analyze the withstand voltage stability and insulation performance of the power cable in combination with the voltage conditions, leakage current conditions, temperature conditions and partial discharge conditions of the power cable in the withstand voltage test, thereby improving the coverage of the withstand voltage stability evaluation of the power cable, thereby improving the persuasiveness of the insulation performance evaluation of the power cable, and at the same time providing a more targeted basis for the maintenance and repair of the power cable, thereby improving the reliability and safety of the power cable operation.

[0065] See also Figure 2 As shown, the present invention proposes a device, which includes a processor, a memory and a communication bus. The memory stores a computer-readable program that can be executed by the processor. The communication bus realizes the connection and communication between the processor and the memory. When the processor executes the computer-readable program, the variable frequency series resonance withstand voltage test system is realized.

[0066] The embodiment of the present invention adopts a variable frequency series resonance method, which can realize high voltage testing of cables at a lower power supply capacity compared to traditional withstand voltage test methods (such as directly using a high-voltage test transformer). This is because in the resonant state, the reactive power in the circuit is mainly exchanged between the inductor and the cable capacitor, and the power supply only needs to provide the active power part in the circuit, which greatly reduces the requirements for the test power supply capacity. It can be applied to on-site testing of large-capacity cables, reduces the volume and weight of the test equipment, and improves the convenience of the test.

[0067] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they shall all fall within the protection scope of the present invention.

Claims

1. A variable frequency series resonance withstand voltage test system, characterized in that: include: Theoretical resonant frequency calculation module, used to extract the capacitance value of the target power cable and the inductance value of the target reactor in the withstand voltage test, and calculate the theoretical resonant frequency of the target power cable; The output frequency information acquisition module is used to slowly increase the output frequency of the target variable frequency power supply in the withstand voltage test, collect the current value corresponding to the target test circuit at each output frequency in the withstand voltage test, and collect the voltage value at both ends of the target power cable at each output frequency; The test resonance frequency evaluation module is used to evaluate whether the test resonance frequency of the target power cable in the withstand voltage test is accurate. If it is accurate, the withstand voltage test information acquisition module is executed. If it is inaccurate, it indicates that the withstand voltage test cannot be continued and feedback is given; The withstand voltage test information collection module is used to keep the test resonance frequency unchanged during the withstand voltage test, set the test voltage of the target power cable during the withstand voltage test, extract the reasonable range of the leakage current of the target power cable, and collect the number of discharges of each cable section in the withstand voltage test, the discharge amount corresponding to each discharge, the cable temperature, and the voltage and leakage current corresponding to each monitoring time point; The withstand voltage performance stability analysis module is used to analyze the withstand voltage performance stability of each cable segment in the target power cable during the withstand voltage test; The power cable insulation performance evaluation module is used to evaluate whether the insulation performance of the target power cable is qualified, and provide feedback if it is unqualified.

2. A variable frequency series resonance withstand voltage test system according to claim 1, characterized in that: The method for calculating the theoretical resonant frequency of the target power cable is: The capacitance value of the target power cable and the inductance value of the target reactor in the withstand voltage test are recorded as C and L respectively; Calculate the theoretical resonant frequency f of the target power cable 理 , 3. A variable frequency series resonance withstand voltage test system according to claim 2, characterized in that: The specific process of evaluating whether the test resonant frequency of the target power cable in the withstand voltage test is accurate is as follows: With the output frequency as the horizontal coordinate and the current value as the vertical coordinate, a current-frequency curve in the withstand voltage test is constructed, and the output frequency corresponding to the maximum current value is located from the curve, and recorded as the first output frequency; With the output frequency as the horizontal coordinate and the voltage value at both ends as the vertical coordinate, a voltage-frequency curve in the withstand voltage test is constructed, and the output frequency corresponding to the voltage peak is located from the curve and recorded as the second output frequency; Calculate the test resonant frequency accuracy β of the target power cable in the withstand voltage test; The test resonant frequency accuracy of the target power cable in the voltage withstand test is compared with the resonant frequency accuracy of the set reference. If the test resonant frequency accuracy of the target power cable in the voltage withstand test is greater than or equal to the resonant frequency accuracy of the set reference, it indicates that the test resonant frequency of the target power cable in the voltage withstand test is accurate; otherwise, it indicates that the test resonant frequency of the target power cable in the voltage withstand test is inaccurate.

4. A variable frequency series resonance withstand voltage test system according to claim 3, characterized in that: The specific process of calculating the test resonant frequency accuracy of the target power cable in the withstand voltage test is as follows: Subtract the theoretical resonant frequency of the target power cable from the first output frequency to obtain an output frequency deviation between the theoretical resonant frequency and the first output frequency, and record it as △f1; Subtract the theoretical resonant frequency of the target power cable from the second output frequency to obtain an output frequency deviation between the theoretical resonant frequency and the second output frequency, and record it as △f2; Subtract the first output frequency from the second output frequency to obtain an output frequency deviation between the first output frequency and the second output frequency, and record it as △f3; Calculate the test resonant frequency accuracy β of the target power cable in the withstand voltage test, Here, Δf represents the output frequency deviation allowed by the setting, and e represents a natural constant.

5. The variable frequency series resonance withstand voltage test system according to claim 1, characterized in that: The specific process of analyzing the stability of the withstand voltage performance of each cable segment in the target power cable during the withstand voltage test is as follows: Based on the number of discharges of each cable segment in the target power cable during the withstand voltage test, the discharge amount corresponding to each discharge, the cable temperature, and the voltage and leakage current corresponding to each monitoring time point, the voltage stability χ of each cable segment in the target power cable during the withstand voltage test is calculated respectively. i 、Leakage current reasonableness δ i , Partial discharge abnormality index and temperature anomaly index θ i , where i represents the number of the cable segment, i=1,2,...,n; Calculate the voltage withstand performance stability of each cable segment in the target power cable during the voltage withstand test Among them, a1, a2, a3 and a4 respectively represent the weights of the set voltage stability, leakage current rationality, partial discharge abnormality index and temperature abnormality index corresponding to the withstand voltage performance stability assessment, a1+a2+a3+a4=1.

6. A variable frequency series resonance withstand voltage test system according to claim 5, characterized in that: The specific process of calculating the voltage stability of each cable segment in the target power cable during the voltage withstand test is as follows: The voltage corresponding to each monitoring time point of each cable segment in the target power cable in the withstand voltage test is subtracted from the test voltage of the target power cable in the withstand voltage test to obtain the voltage deviation corresponding to each monitoring time point of each cable segment in the withstand voltage test, and the voltage deviation is compared with the voltage deviation set as the reference of the corresponding cable segment. If the voltage deviation corresponding to a certain monitoring time point in the withstand voltage test of a cable segment is greater than or equal to the voltage deviation set as the reference of the cable segment, the monitoring time point is recorded as an abnormal time point, and the number of abnormal time points of each cable segment in the withstand voltage test of the target power cable is counted and recorded as ε i ; Calculate the voltage stability x of each cable section in the target power cable during the withstand voltage test i , Among them, ε′ represents the number of abnormal time points set as reference.

7. The variable frequency series resonance withstand voltage test system according to claim 5, characterized in that: The specific process of calculating the rationality of the leakage current of each cable segment in the target power cable during the withstand voltage test is as follows: The leakage current corresponding to each monitoring time point of each cable segment in the target power cable during the withstand voltage test is compared with the reasonable range of the leakage current of the target power cable. If the leakage current corresponding to each monitoring time point of a cable segment in the target power cable during the withstand voltage test is within the reasonable range of the leakage current, the reasonable degree of the leakage current of the cable segment during the withstand voltage test is recorded as τ1; If the leakage current corresponding to the monitoring time point of a cable section in the target power cable during the withstand voltage test is not within the reasonable range of the leakage current, the reasonableness of the leakage current of the cable section during the withstand voltage test is recorded as τ2; If the leakage current corresponding to each monitoring time point of a cable section in the target power cable during the withstand voltage test is not within the reasonable range of leakage current, the reasonableness of the leakage current of the cable section during the withstand voltage test is recorded as τ3; In summary, the reasonableness of leakage current δ of each cable section in the target power cable during the withstand voltage test is obtained: i , δ i The value of is τ1 or τ2 or τ3, where τ1>τ2>τ3.

8. The variable frequency series resonance withstand voltage test system according to claim 5, characterized in that: The specific process of calculating the partial discharge abnormality index of each cable section in the target power cable during the voltage withstand test is as follows: The number of discharges of each cable segment in the target power cable during the withstand voltage test is recorded as μ i ; The discharge amount corresponding to each discharge of each cable segment in the target power cable during the withstand voltage test is accumulated to obtain the total discharge amount of each cable segment in the target power cable during the withstand voltage test, which is recorded as Q i ; Calculate the partial discharge anomaly index of each cable section in the target power cable during the withstand voltage test Here, μ′ and Q′ represent the discharge number and discharge amount of the set reference, respectively.

9. The variable frequency series resonance withstand voltage test system according to claim 5, characterized in that: The specific process of evaluating whether the insulation performance of the target power cable is qualified is as follows: Calculate the insulation performance qualification of the target power cable ξ, Among them, ζ′ represents the stability of the withstand voltage performance of the set reference, and n represents the number of cable segments; The insulation performance qualification of the target power cable is compared with the insulation performance qualification of the set reference. If the insulation performance qualification of the target power cable is less than the insulation performance qualification of the set reference, it indicates that the insulation performance of the target power cable is unqualified. Otherwise, it indicates that the insulation performance of the target power cable is qualified.

10. A device, characterized in that: include: Processor, memory and communication bus; The memory stores a computer-readable program executable by the processor; The communication bus realizes the connection and communication between the processor and the memory; When the processor executes the computer-readable program, the variable frequency series resonant withstand voltage test system as described in any one of claims 1 to 9 is implemented.

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