A high voltage frequency domain dielectric spectrum testing system and method

Abstract

The present invention discloses a high-voltage frequency-domain dielectric spectrum test system and method, and relates to the field of high-voltage test technology. The high-voltage frequency-domain dielectric spectrum test system includes: a high-voltage power supply module, a frequency-domain dielectric spectrum test module, a synchronous data acquisition module, and a low-ripple variable frequency power supply module. The present invention performs an initialization test on a sinusoidal wave power supply to obtain a sinusoidal wave stability coefficient and judge whether to perform a frequency-domain dielectric spectrum test, and then judges whether to perform synchronous data acquisition based on the obtained test accuracy coefficient, and finally judges whether to send a power drive instruction based on the obtained synchronization performance evaluation value. If so, the power supply mode is switched by a high-voltage isolation switch, otherwise, an instruction not to switch the power supply mode is sent, thereby achieving an improvement in the low-ripple anti-interference ability during the high-voltage frequency-domain dielectric spectrum test, and solving the problem of low low-ripple anti-interference ability during the high-voltage frequency-domain dielectric spectrum test in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of high voltage testing, and in particular to a high voltage frequency domain dielectric spectrum testing system and method. Background Art

[0002] With the development of the electric power industry, the insulation performance evaluation of high-voltage electrical equipment has become increasingly important. Traditional insulation test methods, such as insulation resistance test and leakage current test, can reflect the insulation condition of the equipment to a certain extent, but they often have problems such as low test accuracy and inability to detect the nonlinear characteristics of insulation degradation. Therefore, a more accurate and reliable test method is needed to evaluate the insulation performance of high-voltage electrical equipment. High-voltage frequency domain dielectric spectrum test technology came into being in this context. It has the advantages of high test accuracy and the ability to detect the nonlinear characteristics of insulation degradation. Therefore, it is widely used in the insulation performance evaluation of high-voltage electrical equipment.

[0003] In the existing technology, under the control of a computer, the signal generator outputs an AC signal of a specific frequency and amplitude. The signal is amplified by a high-voltage amplifier, filtered by an output filter, and then output to the sample under test from the high-voltage output terminal. It is then converted into a voltage signal by a micro-current amplifier, and finally the voltage signal is processed through a dual channel to obtain the dielectric parameters of the sample under test.

[0004] For example, the invention patent announcement number is CN117686795B, which announces a high-voltage frequency-domain dielectric spectrum testing device and method, including: converting the digital signal output by the PC software into an analog signal of ±10V, and inputting it into the high-voltage amplifier device as a test signal; amplifying the test signal to obtain a high-voltage signal, and applying it to the high-voltage end of the product to be tested through a measuring cable, so that the high-voltage signal outputs a current signal from the measuring loop after passing through the product to be tested; respectively collecting the voltage-dividing signal of the high-voltage amplifier device and the current signal amplified by the micro-current amplifier, and reporting the collected results to the PC; analyzing the voltage-dividing signal and the current signal by FFT to determine the phase angle and complex impedance of the voltage-dividing signal and the current signal; and calculating the dielectric loss factor of the system based on the phase angle and complex impedance.

[0005] For example, the detection device and detection method of a frequency domain dielectric spectrum tester announced by the invention patent with the announcement number: CN113238132B include: S1, starting the upper computer and the lower computer; S2, the upper computer sends a self-test instruction to the lower computer, the lower computer enters the self-test state and sends the self-test result to the upper computer, if the self-test result is normal, execute S3, if the self-test result is abnormal, both the upper computer and the lower computer stop working; S3, select the detection mode on the upper computer, set the detection frequency and voltage parameters of the detection frequency point and send them to the lower computer, the lower computer adjusts its own parameters according to the detection frequency and voltage parameters, and then collects the detection voltage signal and detection current signal of the object to be tested and sends them to the upper computer, the upper computer calculates the dielectric loss tangent value of the detection frequency point according to the detection voltage signal and the detection current signal and saves it; S4, repeat S3 until all the detection frequency points are detected, and the upper computer and the lower computer stop working; S5, the detection of the detection frequency point is completed.

[0006] However, in the process of implementing the technical solution of the invention in the embodiments of the present application, the present application found that the above technology has at least the following technical problems:

[0007] In the prior art, during the on-site testing of power equipment, there is often strong electromagnetic field interference. These interference signals may be much larger than the weak current signals generated by the sample being tested, making it difficult for existing test systems to maintain stable test performance under strong electromagnetic field interference conditions, which in turn leads to reduced credibility of the test results. There is also a problem of low low ripple anti-interference capability during high-voltage frequency domain dielectric spectrum testing. Summary of the invention

[0008] The embodiments of the present application provide a high-voltage frequency domain dielectric spectrum testing system and method, thereby solving the problem of low low ripple anti-interference capability in the high-voltage frequency domain dielectric spectrum testing process in the prior art, and achieving improved low ripple anti-interference capability in the high-voltage frequency domain dielectric spectrum testing process.

[0009] The embodiment of the present application provides a high-voltage frequency-domain dielectric spectrum test system, including: a high-voltage power supply module, a frequency-domain dielectric spectrum test module, a synchronous data acquisition module and a low-ripple variable frequency power supply module; wherein the high-voltage power supply module is used to perform an initialization test on a sinusoidal wave power supply to obtain a sinusoidal wave stability coefficient, and determine whether to perform a frequency-domain dielectric spectrum test based on the obtained sinusoidal wave stability coefficient, and the sinusoidal wave stability coefficient is used to quantify the stability of the power ripple generated by the sinusoidal wave power supply within an expected working cycle; the frequency-domain dielectric spectrum test module is used to monitor the dielectric parameters of a dielectric material to be tested at different preset frequencies in real time to obtain a test accuracy coefficient, and at the same time determine whether to perform synchronous data acquisition based on the obtained test accuracy coefficient, and the test accuracy coefficient is used to quantify the reliability of the frequency-domain dielectric spectrum test; the synchronous data acquisition module is used to convert the operating parameters after synchronous acquisition into digital signals and store them to obtain a synchronous performance evaluation value, and the synchronous performance evaluation value is used to evaluate the synchronous performance of synchronous data acquisition; the low-ripple variable frequency power supply module is used to determine whether to send a power drive instruction according to the obtained synchronous performance evaluation value, and if so, the high-voltage isolation switch switches the power mode, otherwise, a non-switching power mode instruction is sent.

[0010] Furthermore, the synchronous data acquisition module includes a central control unit, a high-voltage power supply ADC acquisition unit and a dielectric current ADC acquisition unit to be tested; the central control unit is used to synchronously control the high-voltage power supply ADC acquisition unit and the dielectric current ADC acquisition unit to be tested, and simultaneously store the acquired digital signals and receive power drive instructions and non-switching power mode instructions; the high-voltage power supply ADC acquisition unit is used to generate and adjust the high-voltage power supply applied to the dielectric material to be tested, and simultaneously measure and record the waveform and voltage parameters of the output voltage in real time, and the voltage parameters include voltage amplitude and voltage phase; the dielectric current ADC acquisition unit to be tested is used to measure and record the current in the current loop, and simultaneously collect and record the waveform and current parameters of the output current in real time, the current loop represents a loop in which the dielectric material to be tested is placed between the high-voltage power supply and the ground, and the current parameters include current amplitude and current phase.

[0011] Furthermore, the specific steps for obtaining the sinusoidal wave stability coefficient are: when the obtained voltage peak is within the allowable range of the voltage peak obtained from the preset database and the output continuous current within the preset working cycle is equal to the preset output continuous current obtained from the preset database, real-time monitoring of the working state of the sinusoidal wave power supply within the preset working cycle; obtaining the sinusoidal wave distortion score of the sinusoidal wave signal at the current working moment, and at the same time obtaining and recording the interference ripple on the sinusoidal wave signal to obtain the interference ripple amplitude score and the interference ripple frequency score, and combining the preset electromagnetic field interference factor obtained from the preset database to obtain the sinusoidal wave stability coefficient; the sinusoidal wave distortion score represents the ratio of the harmonic component to the fundamental component; the interference ripple amplitude score represents the complement of the ratio of the interference ripple amplitude at the current working moment to the interference ripple amplitude at the previous working moment; the interference ripple frequency score represents the complement of the ratio of the interference ripple frequency at the current working moment to the interference ripple frequency at the previous working moment.

[0012] Furthermore, the specific limiting expression of the sine wave stability coefficient is:

[0013] ;

[0014] Where t is the number of the current working moment in the preset working cycle, , T is the total number of current working moments in the preset working cycle, e is a natural constant, Indicates the sine wave stability coefficient of the sine wave power supply within the preset working cycle. represents the electromagnetic field interference factor, It represents the sine wave distortion fraction of the sine wave signal at the current working time t. It represents the interference ripple amplitude fraction of the sine wave signal at the current working time t, It represents the interference ripple frequency fraction of the sine wave signal at the current working time t, Indicates the voltage peak value of the sine wave power supply within the preset working cycle. Indicates the allowable range of voltage peak. Indicates the continuous output current of the sine wave power supply within the preset working cycle. Indicates the preset output continuous current.

[0015] Furthermore, the process of obtaining the synchronization performance evaluation value is as follows: E1, obtain the current transformation ratio score and determine whether the obtained current transformation ratio score is equal to the preset current transformation ratio score obtained from the preset database. If so, obtain the maximum AC voltage deviation and the maximum AC current deviation and execute E2, otherwise the synchronization performance evaluation value is not calculated and the early warning mechanism is triggered; E2, when the maximum AC voltage deviation is not greater than the preset maximum AC voltage deviation obtained from the preset database and the maximum AC current deviation is not greater than the preset maximum AC current deviation obtained from the preset database, execute E3; E3, de-normalize the obtained maximum AC voltage deviation and maximum AC current deviation respectively, and obtain the synchronization performance evaluation value by combining the obtained sinusoidal wave stability coefficient and the test accuracy coefficient; the maximum AC voltage deviation represents the maximum value of the AC voltage deviation output between adjacent synchronous acquisition channels at the end of the preset test period; the maximum AC current deviation represents the maximum value of the AC current deviation output between adjacent synchronous acquisition channels at the end of the preset test period.

[0016] The embodiment of the present application provides a high-voltage frequency-domain dielectric spectrum testing method, comprising the following steps: step 1, performing an initialization test on a sinusoidal wave power supply to obtain a sinusoidal wave stability coefficient, and judging whether to perform a frequency-domain dielectric spectrum test based on the obtained sinusoidal wave stability coefficient, wherein the sinusoidal wave stability coefficient is used to quantify the stability of the power ripple generated by the sinusoidal wave power supply within the expected working cycle; step 2, real-time monitoring of the dielectric parameters of the dielectric material to be tested at different preset frequencies to obtain a test accuracy coefficient, and judging whether to perform synchronous data acquisition based on the obtained test accuracy coefficient, wherein the test accuracy coefficient is used to quantify the reliability of the frequency-domain dielectric spectrum test; step 3, converting the operating parameters after synchronous acquisition into digital signals and storing them to obtain a synchronous performance evaluation value, wherein the synchronous performance evaluation value is used to evaluate the synchronization performance of synchronous data acquisition; step 4, judging whether to send a power drive instruction based on the obtained synchronous performance evaluation value, and if so, switching the power mode by the high-voltage isolating switch, otherwise sending an instruction not to switch the power mode.

[0017] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0018] 1. Perform an initialization test on the sinusoidal wave power supply to obtain the sinusoidal wave stability coefficient and determine whether to perform the frequency domain dielectric spectrum test. Then, determine whether to perform synchronous data acquisition based on the obtained test accuracy coefficient. Finally, determine whether to send a power drive instruction based on the obtained synchronization performance evaluation value. If so, the high-voltage isolation switch switches the power mode. Otherwise, a command not to switch the power mode is sent, thereby improving the accuracy and reliability of the frequency domain dielectric spectrum test, and further improving the low ripple anti-interference ability during the high-voltage frequency domain dielectric spectrum test, effectively solving the problem of low low ripple anti-interference ability during the high-voltage frequency domain dielectric spectrum test in the prior art.

[0019] 2. By real-time monitoring of the working status of the sinusoidal wave power supply within a preset working cycle, the sinusoidal wave distortion score of the sinusoidal wave signal at the current working moment is obtained. At the same time, the interference ripple on the sinusoidal wave signal is obtained and recorded to obtain the interference ripple amplitude score and the interference ripple frequency score. The sinusoidal wave stability coefficient is obtained by combining the preset electromagnetic field interference factor obtained from the preset database, thereby achieving an improvement in the accuracy of obtaining the sinusoidal wave stability coefficient, and then achieving a more accurate evaluation of the ripple stability of the sinusoidal wave power supply.

[0020] 3. By judging whether the obtained current transformation ratio score is equal to the preset current transformation ratio score obtained from the preset database, if so, the maximum AC voltage deviation and the maximum AC current deviation are obtained and denormalized respectively, and the obtained sinusoidal wave stability coefficient and the test accuracy coefficient are combined to obtain the synchronization performance evaluation value, thereby achieving an improvement in the accuracy of obtaining the synchronization performance evaluation value, and then achieving a more accurate evaluation of the synchronization performance of synchronous data acquisition. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of a high-voltage frequency-domain dielectric spectrum testing system provided in an embodiment of the present application;

[0022] Figure 2 A structural block diagram of a single oil-paper insulation bushing for a three-phase transformer provided in an embodiment of the present application;

[0023] Figure 3 A flow chart of a high-voltage frequency-domain dielectric spectrum testing method provided in an embodiment of the present application;

[0024] Figure 4 A specific flow chart of frequency domain dielectric spectrum testing of a transformer bushing provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The embodiment of the present application solves the problem of low low ripple anti-interference ability in the high-voltage frequency domain dielectric spectrum test process in the prior art by providing a high-voltage frequency domain dielectric spectrum test system and method. The sinusoidal wave power supply is initialized and tested by a high-voltage power supply module to obtain a sinusoidal wave stability coefficient. At the same time, it is determined whether to perform a frequency domain dielectric spectrum test based on the obtained sinusoidal wave stability coefficient. Then, the dielectric parameters of the dielectric material to be tested at different preset frequencies are monitored in real time by the frequency domain dielectric spectrum test module to obtain a test accuracy coefficient. At the same time, it is determined whether to perform synchronous data acquisition based on the obtained test accuracy coefficient. Then, the operating parameters after synchronous acquisition are converted into digital signals by the synchronous data acquisition module and stored to obtain a synchronous performance evaluation value. Finally, the low ripple variable frequency power supply module is used to determine whether to send a power drive instruction according to the obtained synchronous performance evaluation value. If so, the power mode is switched by the high-voltage isolation switch. Otherwise, an instruction not to switch the power mode is sent, thereby improving the low ripple anti-interference ability in the high-voltage frequency domain dielectric spectrum test process.

[0026] The technical solution in the embodiment of the present application is to solve the problem that the low ripple anti-interference ability is not high in the above-mentioned high-voltage frequency domain dielectric spectrum test process. The overall idea is as follows:

[0027] By performing an initialization test on the sinusoidal wave power supply to obtain the sinusoidal wave stability coefficient and determine whether to perform the frequency domain dielectric spectrum test, then determining whether to perform synchronous data acquisition based on the obtained test accuracy coefficient, and finally determining whether to send a power drive instruction based on the obtained synchronization performance evaluation value, the effect of improving the low ripple anti-interference capability during the high-voltage frequency domain dielectric spectrum test is achieved.

[0028] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] like Figure 1 As shown, it is a structural schematic diagram of a high-voltage frequency-domain dielectric spectrum test system provided in an embodiment of the present application. A high-voltage frequency-domain dielectric spectrum test system provided in an embodiment of the present application includes: a high-voltage power supply module, a frequency-domain dielectric spectrum test module, a synchronous data acquisition module and a low-ripple variable frequency power supply module;

[0030] Among them, the high-voltage power supply module is used to provide a high-voltage output in the form of a sine wave, and at the same time, the sine wave power supply is initialized and tested to obtain the sine wave stability coefficient. Based on the obtained sine wave stability coefficient, it is determined whether to perform a frequency domain dielectric spectrum test. The sine wave stability coefficient is used to quantify the stability of the power ripple generated by the sine wave power supply within the expected working cycle; the frequency domain dielectric spectrum test module is used to monitor the dielectric parameters of the dielectric material to be tested at different preset frequencies in real time to obtain the test accuracy coefficient, and at the same time, based on the obtained test accuracy coefficient, it is determined whether to perform synchronous data acquisition. The test accuracy coefficient is used to quantify the reliability of the frequency domain dielectric spectrum test; the synchronous data acquisition module is used to convert the operating parameters after synchronous acquisition into digital signals and store them to obtain synchronous performance evaluation values. The synchronous performance evaluation values ​​are used to evaluate the synchronization performance of synchronous data acquisition; the low ripple variable frequency power supply module is used to determine whether to send a power drive instruction based on the obtained synchronous performance evaluation value. If so, the high-voltage isolation switch switches the power mode, otherwise a command not to switch the power mode is sent.

[0031] Among them, the initialization test is used to monitor the interference of the sinusoidal wave power supply in real time within the preset working cycle; the frequency domain dielectric spectrum test is used to evaluate the insulation state and moisture content of the dielectric material to be tested; the dielectric parameters include insulation resistance, dielectric constant, dielectric loss factor, dielectric loss angle, and current amplitude and current phase flowing through the dielectric material to be tested; synchronous data acquisition is used to realize four-channel synchronous data acquisition; the operating parameters are the data on the transmission line during the frequency domain dielectric spectrum test; the operating parameters include active current, reactive current, AC voltage and AC current.

[0032] The high-voltage and low-ripple frequency conversion power supply has a pure sine wave output of 10kV voltage and 0.001Hz to 10kHz. The conditions for pure sine wave output are: the oil-paper bushing inside the transformer with insulation performance is recorded as an oil-paper insulated bushing transformer, that is, the dielectric loss factor in the frequency domain dielectric spectrum test process is 0.153%, and the ratio of active current to reactive current in the output current is 0.153%.

[0033] In this embodiment, the high voltage is usually above 10kV, and the working principle of the high voltage power supply module is: to provide a stable sinusoidal power supply within the frequency range of 1mHz-10kHz, with a continuous output current of 500mA, and has the characteristics of low interference ripple (not more than 0.2%), low sinusoidal wave distortion (not more than 0.5%) and low frequency fluctuation (not more than 0.05%). The initialization test is used to evaluate the interference degree of the sinusoidal power supply during operation, which helps to ensure the stability of the frequency domain dielectric spectrum test, thereby ensuring the accuracy and reliability of the frequency domain dielectric spectrum test results.

[0034] It should be noted that the high-voltage frequency-domain dielectric spectrum test system and method have been widely used in the dielectric property testing of various materials. For example, in the power system, the dielectric material to be tested is usually the oil-paper bushing inside the transformer. Moisture defects are one of the main factors leading to failure of the oil-paper bushing inside the transformer. Through high-voltage frequency-domain dielectric spectrum testing, the insulation performance of the oil-paper bushing inside the transformer can be accurately evaluated, potential moisture defects can be discovered in time and corresponding maintenance measures can be taken, which provides strong support for the adaptability and potential applications of the oil-paper bushing inside the transformer, and effectively solves the problem that the moisture or aging degree of the oil-paper bushing inside the transformer cannot be accurately evaluated.

[0035] like Figure 2 , which is a structural block diagram of a single oil-paper insulation bushing of a three-phase transformer provided in an embodiment of the present application, Figure 2 The test host in the test is the host of the frequency domain dielectric spectrum tester. The test requires that all bushings connected to the oil-paper bushing inside the transformer to be tested through the winding must be short-circuited and pressurized, and the non-measurement winding bushings must be short-circuited and grounded, thereby realizing synchronous, efficient and accurate measurement of the oil-paper bushings inside multiple transformers, providing strong technical support for the safe and stable operation of the power system.

[0036] Furthermore, the synchronous data acquisition module includes a central control unit, a high-voltage power supply ADC acquisition unit and a dielectric current ADC acquisition unit to be tested; the central control unit is used to synchronously control the high-voltage power supply ADC acquisition unit and the dielectric current ADC acquisition unit to be tested, and simultaneously store the acquired digital signals and receive power drive instructions and instructions not to switch power modes; the high-voltage power supply ADC acquisition unit is used to generate and adjust the high-voltage power supply applied to the dielectric material to be tested, and simultaneously measure and record the waveform and voltage parameters of the output voltage in real time, and the voltage parameters include voltage amplitude and voltage phase; the dielectric current ADC acquisition unit to be tested is used to measure and record the current in the current loop, and simultaneously collect and record the waveform and current parameters of the output current in real time, the current loop represents a loop in which the dielectric material to be tested is placed between the high-voltage power supply and the ground, and the current parameters include current amplitude and current phase.

[0037] In this embodiment, the waveform and voltage parameters of the output voltage, the waveform and current parameters of the output current are recorded in real time by an oscilloscope, wherein the output current represents the current value output from the power supply in the current loop; the central control unit can accurately and synchronously control the high-voltage power supply ADC acquisition unit and the dielectric current ADC (Analog-to-Digital Converter) acquisition unit to be tested, ensuring that the two are consistent in time, thereby avoiding the phase error caused by asynchronous acquisition, and the high-voltage power supply ADC acquisition unit and the dielectric current ADC acquisition unit to be tested both have high-precision measurement capabilities without waiting or delay, thereby improving the real-time and accuracy of data acquisition, thereby achieving the improvement of the stability and reliability of the dielectric material to be tested during the frequency domain dielectric spectrum test process.

[0038] Furthermore, the specific steps for obtaining the sine wave stability coefficient are: obtaining a voltage peak value of the sine wave power supply within a preset working cycle and determining whether the obtained voltage peak value is within an allowable range of a voltage peak value obtained from a preset database, and determining whether an output continuous current within the preset working cycle is equal to a preset output continuous current obtained from the preset database; when the obtained voltage peak value is within an allowable range of a voltage peak value obtained from the preset database and the output continuous current within the preset working cycle is equal to the preset output continuous current obtained from the preset database, real-time monitoring of the working state of the sine wave power supply within the preset working cycle; The sinusoidal wave distortion score of the sinusoidal wave signal at the current working moment is obtained, and the interference ripple on the sinusoidal wave signal is obtained and recorded to obtain the interference ripple amplitude score and the interference ripple frequency score, and the sinusoidal wave stability coefficient is obtained by combining the preset electromagnetic field interference factor obtained from the preset database; the sinusoidal wave distortion score represents the ratio of the harmonic component to the fundamental component; the interference ripple amplitude score represents the complement of the ratio of the interference ripple amplitude at the current working moment to the interference ripple amplitude at the previous working moment; the interference ripple frequency score represents the complement of the ratio of the interference ripple frequency at the current working moment to the interference ripple frequency at the previous working moment.

[0039] Among them, the specific limiting expression of the sine wave stability coefficient is:

[0040] ;

[0041] ;

[0042] ;

[0043] ;

[0044] Where t is the number of the current working moment in the preset working cycle, , T is the total number of current working moments in the preset working cycle, e is a natural constant, Indicates the sine wave stability coefficient of the sine wave power supply within the preset working cycle. represents the electromagnetic field interference factor, It represents the sine wave distortion fraction of the sine wave signal at the current working time t. Represents the harmonic component of the sine wave signal at the current working time t, represents the fundamental component of the sine wave signal, It represents the interference ripple amplitude fraction of the sine wave signal at the current working time t, It represents the interference ripple amplitude of the sine wave signal at the current working time t, It represents the interference ripple amplitude of the sine wave signal at the last working time t-1, It indicates the initial interference ripple amplitude of the sine wave signal before working. It represents the interference ripple frequency fraction of the sine wave signal at the current working time t, It represents the interference ripple frequency of the sine wave signal at the current working time t, It represents the interference ripple frequency of the sine wave signal at the last working time t-1, Indicates the initial interference ripple frequency of the sine wave signal before it works. Indicates the voltage peak value of the sine wave power supply within the preset working cycle. Indicates the allowable range of voltage peak. Indicates the continuous output current of the sine wave power supply within the preset working cycle. Indicates the preset output continuous current.

[0045] In this embodiment, the output continuous current, harmonic components and fundamental components are all recorded in real time by an oscilloscope, and the interference ripple frequency and interference ripple amplitude are measured by a spectrum analyzer. It should be understood that since it is necessary to determine the influence of the voltage peak on the stability of the sinusoidal wave signal in this example, in order to avoid the influence of the output current in the current loop on the voltage peak, it is necessary to limit the output current to a continuous value at this time. Therefore, before calculating the sinusoidal wave stability coefficient, it is necessary to consider that the obtained output continuous current is equal to the preset output continuous current; the sinusoidal wave signal is generated by the sinusoidal wave power supply during operation, the voltage peak is a positive number, and a preset working cycle only contains one complete sine wave, that is, a preset working cycle has only one voltage peak, and a preset working cycle contains multiple working moments. The allowable range of the voltage peak is usually set to 50V-10kV, and the preset output continuous current is usually set to 100mA.

[0046] The value range of the electromagnetic field interference factor in this example is limited to between 0 and 1, which is usually the degree of influence of the electromagnetic field strength preset in the preset database on the process of obtaining the sine wave stability coefficient. Specifically, the preset database stores the electromagnetic field interference factor corresponding to the sine wave stability coefficient. There is a preset mapping relationship between this interference factor and the sine wave stability coefficient. This mapping relationship can be one-to-one or many-to-one. In practical applications, the real-time sine wave stability coefficient can be input into this mapping relationship to quickly obtain the corresponding electromagnetic field interference factor, which provides an important quantitative indicator for evaluating the stability of the sine wave power supply output, and then more accurately calculates the sine wave stability coefficient.

[0047] The aforementioned preset database is a database for storing various types of setting data established before the design of the high-voltage frequency domain dielectric spectrum testing system and method. The preset database includes but is not limited to the allowable range of voltage peak, electromagnetic field interference factor, sinusoidal wave stability threshold range, preset current transformation ratio fraction and preset working cycle, and various values ​​therein are directly set by technicians. Among them, the setting basis of the allowable range of voltage peak can be determined according to the actual scenario of the high-voltage frequency domain dielectric spectrum test of the oil-paper bushing inside the transformer. For example, the allowable range of voltage peak is the range corresponding to the maximum and minimum values ​​of the historical voltage peak of the oil-paper bushing inside the transformer in the preset database. In addition, various values ​​in the preset database can be set and fine-tuned by technicians according to actual debugging.

[0048] It should be understood that the statistical table of changes in the sine wave stability coefficient is shown in Table 1:

[0049] Table 1 Statistics of changes in sine wave stability coefficient

[0050]

[0051] It can be seen from Table 1 that the sine wave stability coefficient decreases with the increase of the electromagnetic field interference factor, the sine wave distortion fraction, the interference ripple amplitude fraction and the interference ripple frequency fraction. Among them, the electromagnetic field interference factor affects the value of the sine wave interference coefficient by affecting the values ​​of the sine wave distortion fraction, the interference ripple amplitude fraction and the interference ripple frequency fraction. By considering the influence of the electromagnetic field strength (obtained by a field strength meter) on the output stability of the sine wave power supply, it helps to ensure the accuracy and effectiveness of the obtained sine wave stability coefficient.

[0052] It should be noted that the sine wave distortion fraction also indirectly affects the value of the interference ripple amplitude fraction. When the sine wave output by the sinusoidal power supply is distorted, the harmonic components in its waveform will increase. These harmonic components will cause fluctuations or "ripples" on the waveform, that is, the interference ripple amplitude fraction will increase accordingly, thereby indirectly increasing the interference ripple amplitude fraction.

[0053] The interference ripple frequency score also indirectly affects the value of the interference ripple amplitude score. When the interference ripple frequency score increases, it means that the difference between the frequency of the interference ripple and the fundamental frequency of the sine wave increases. This frequency difference may cause the fluctuation amplitude of the sine wave waveform to increase. When waveforms of different frequencies are superimposed together, a beat frequency effect may be produced, resulting in an increase in the waveform amplitude at certain time points, thereby increasing the interference ripple amplitude score.

[0054] By considering the above-mentioned indirect influence mechanism, we can have a more comprehensive understanding of the factors affecting the output stability of the sinusoidal power supply. In the process of high-voltage frequency-domain dielectric spectrum testing, the suppression efficiency of low ripple interference is crucial to the accuracy of the test results. Understanding the interaction between the sinusoidal distortion fraction, the interference ripple amplitude fraction, and the interference ripple frequency fraction is helpful to design a more effective low ripple interference suppression method, thereby achieving the improvement of the low ripple anti-interference capability in the process of high-voltage frequency-domain dielectric spectrum testing, and effectively solving the problem of low low ripple anti-interference capability in the process of high-voltage frequency-domain dielectric spectrum testing in the prior art.

[0055] Furthermore, the specific process of determining whether to perform the frequency domain dielectric spectrum test based on the obtained sinusoidal wave stability coefficient is as follows: determine whether the obtained sinusoidal wave stability coefficient is within the sinusoidal wave stability threshold range obtained from the preset database (including the case where it is equal to the maximum and minimum values ​​of the historical sinusoidal wave stability coefficient). If so, perform the frequency domain dielectric spectrum test, otherwise do not perform the frequency domain dielectric spectrum test and prompt the preset personnel to perform maintenance; the test accuracy coefficient is obtained by the following method: when the obtained sinusoidal wave stability coefficient is within the sinusoidal wave stability threshold range obtained from the preset database, measure and record the measurement parameters of the dielectric material to be tested at each preset frequency, and the measurement parameters include insulation resistance, dielectric constant, dielectric loss angle and dielectric loss factor; obtain the current amplitude coefficient, and at the same time obtain the test accuracy coefficient in combination with the reference measurement parameters obtained from the preset database; the current amplitude coefficient is obtained by processing the preset frequency, current amplitude, current phase and working time; the reference measurement parameters include reference insulation resistance, reference dielectric constant, reference dielectric loss angle, reference dielectric loss factor, reference insulation resistance deviation, reference dielectric constant deviation, reference dielectric loss angle deviation and reference dielectric loss factor deviation.

[0056] Among them, when the obtained sine wave stability coefficient is within the sine wave stability threshold range, the specific limiting expression of the test accuracy coefficient is:

[0057] ;

[0058] ;

[0059] Where i is the number of the preset frequency, , Y is the total number of preset frequencies, e is a natural constant, Indicates the test accuracy coefficient of the dielectric material to be tested at different preset frequencies. It represents the current amplitude coefficient of the dielectric material to be tested at the i-th preset frequency, It indicates the working time of the dielectric material to be tested corresponding to the i-th preset frequency, represents the current amplitude of the dielectric material to be tested at the i-th preset frequency, represents the i-th preset frequency of the dielectric material to be tested, represents the current phase of the dielectric material to be tested at the i-th preset frequency, It represents the dielectric loss angle of the dielectric material to be tested at the i-th preset frequency. represents the reference dielectric loss angle, represents the dielectric loss factor of the dielectric material to be tested at the i-th preset frequency, represents the reference dielectric loss factor, represents the reference dielectric loss factor deviation, represents the dielectric constant of the dielectric material to be tested at the i-th preset frequency, represents the reference dielectric constant, represents the reference dielectric constant deviation, represents the insulation resistance of the dielectric material to be tested at the i-th preset frequency, represents the reference insulation resistance, Indicates the reference insulation resistance deviation.

[0060] In this embodiment, the measurement error of the dielectric loss factor should not be greater than ±[2% (reading) + 0.0002],

[0061] During the frequency domain dielectric spectrum test, the measurement error of the capacitance value of the dielectric material to be tested is not greater than ±[0.5% (reading) + 1pF]; the sine wave stability threshold range represents the range corresponding to the maximum and minimum values ​​of the historical sine wave stability coefficient of the sine wave power supply in the preset database in each historical working period; the insulation resistance and dielectric constant are measured by an insulation resistance tester and a dielectric constant tester, respectively, and the dielectric loss angle and dielectric loss factor are measured by a dielectric loss tester; the reference insulation resistance, reference dielectric constant, reference dielectric loss angle and reference dielectric loss factor are respectively represented by the sum and average of the historical insulation resistance, historical dielectric constant, historical dielectric loss angle and historical dielectric loss factor of the dielectric material to be tested in the preset database at each frequency, and the reference insulation resistance deviation, reference dielectric constant deviation, reference dielectric loss angle deviation and reference dielectric loss factor deviation are respectively represented by the sum and average of the historical insulation resistance deviation, historical dielectric constant deviation, historical dielectric loss angle deviation and historical dielectric loss factor deviation of the dielectric material to be tested in the preset database at each frequency.

[0062] It is important to understand that the test accuracy factor increases with the dielectric loss angle deviation (i.e. ), insulation resistance deviation (i.e. ), dielectric loss factor deviation (i.e. ) and dielectric constant deviation (i.e. ) increases and decreases. Among them, the current amplitude coefficient indirectly affects the values ​​of dielectric loss angle deviation and insulation resistance deviation, and then affects the value of test accuracy coefficient, specifically:

[0063] When the current amplitude changes, the electric field strength will change, which will affect the polarization process and energy loss inside the dielectric material to be tested, and cause a deviation between the measured value and the actual value of the dielectric loss angle. This deviation will further affect the test accuracy coefficient, making the test result inaccurate; similarly, when measuring insulation resistance, if the measured value of the current amplitude has a deviation, it will cause the test current to be unstable, thereby affecting the measured value of the insulation resistance. The deviation of the insulation resistance will directly affect the test accuracy coefficient, making the test result unreliable.

[0064] The deviation of the dielectric constant also indirectly affects the value of the dielectric loss factor deviation. When there is a deviation in the dielectric constant, it means that the ability of the dielectric material to be tested to store charge in the electric field has changed. This change will directly affect the polarization process and charge distribution inside the dielectric material to be tested, thereby causing a change in the dielectric loss factor, thereby affecting the value of the dielectric loss factor.

[0065] By considering the influence of the current amplitude coefficient on the dielectric loss angle deviation and the insulation resistance deviation, as well as the indirect influence mechanism of the dielectric constant deviation on the dielectric loss factor deviation, the accuracy of the high-voltage frequency domain dielectric spectrum test and the efficiency of suppressing low ripple interference can be more effectively improved, thereby achieving the improvement of the low ripple anti-interference capability in the high-voltage frequency domain dielectric spectrum test process, and effectively solving the problem of low low ripple anti-interference capability in the high-voltage frequency domain dielectric spectrum test process in the prior art.

[0066] Furthermore, the operating parameters after synchronous acquisition are converted into digital signals and stored. It also includes judging whether the synchronous acquisition channel is qualified. The specific process includes: L1, numbering the four channels and performing synchronous acquisition tests, and obtaining the response time of the four channels at the end of the synchronous acquisition test. The four channels include the first synchronous acquisition channel, the second synchronous acquisition channel, the third synchronous acquisition channel and the fourth synchronous acquisition channel. The response time of the four channels includes the response time of the first channel, the response time of the second channel, the response time of the third channel and the response time of the fourth channel; L2, judging whether the response time of the first channel is less than the preset response time of the first channel obtained from the preset database. If so, the first synchronous acquisition channel is recorded as a qualified channel and L3 is executed. Otherwise, the first synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to inspect the first synchronous acquisition channel and execute L3 after the inspection; L3, judging whether the response time of the second channel is less than the preset response time obtained from the preset database Suppose the preset second channel response time obtained from the database, if so, the second synchronous acquisition channel is recorded as a qualified channel and L4 is executed, otherwise the second synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to repair the second synchronous acquisition channel and execute L4 after the repair; L4, judge whether the third channel response time is less than the preset third channel response time obtained from the preset database, if so, the third synchronous acquisition channel is recorded as a qualified channel and L5 is executed, otherwise the third synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to repair the third synchronous acquisition channel and execute L5 after the repair; L5, judge whether the fourth channel response time is less than the preset fourth channel response time obtained from the preset database, if so, the fourth synchronous acquisition channel is recorded as a qualified channel and the qualified synchronous acquisition test is completed, otherwise the fourth synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to repair the fourth synchronous acquisition channel.

[0067] In this embodiment, the first channel response time, the second channel response time, the third channel response time and the fourth channel response time are obtained through a timer, and the preset first, second, third and fourth channel response time are respectively represented by the sum and average of the historical first, second, third and fourth channel response time of the operating parameters in the preset database during the synchronous channel acquisition process; this example has significant advantages in improving test accuracy, improving test efficiency, reducing maintenance costs, and enhancing test traceability and repeatability through the provided operating parameter synchronous acquisition process, thereby achieving improved accuracy and reliability of synchronous acquisition channel qualified testing.

[0068] Furthermore, the process of obtaining the synchronization performance evaluation value is as follows: E1, when the obtained test accuracy coefficient is within the test accuracy threshold range obtained from the preset database (including the case corresponding to the maximum and minimum values ​​of the historical test accuracy coefficient), obtain the current transformation ratio score and determine whether the obtained current transformation ratio score is equal to the preset current transformation ratio score obtained from the preset database. If so, obtain the maximum AC voltage deviation and the maximum AC current deviation and execute E2, otherwise the synchronization performance evaluation value is not calculated and the early warning mechanism is triggered; E2, determine whether the maximum AC voltage deviation is not greater than the preset maximum AC voltage deviation obtained from the preset database, and at the same time determine whether the maximum AC current deviation is not greater than the preset maximum AC voltage deviation obtained from the preset database. When the maximum AC voltage deviation is not greater than the preset maximum AC voltage deviation obtained from the preset database and the maximum AC current deviation is not greater than the preset maximum AC current deviation obtained from the preset database, execute E3; E3, de-normalize the obtained maximum AC voltage deviation and maximum AC current deviation respectively, and obtain the synchronization performance evaluation value by combining the obtained sinusoidal wave stability coefficient and the test accuracy coefficient; the maximum AC voltage deviation represents the maximum value of the AC voltage deviation output between adjacent synchronous acquisition channels at the end of the preset test period; the maximum AC current deviation represents the maximum value of the AC current deviation output between adjacent synchronous acquisition channels at the end of the preset test period.

[0069] Among them, the specific restriction expression of the synchronization performance evaluation value is:

[0070] ;

[0071] In the formula, r is the number of the synchronous acquisition channel, , e is a natural constant, It represents the synchronous performance evaluation value of the operating parameters on the transmission line during the synchronous acquisition process during the frequency domain dielectric spectrum test. Indicates the maximum AC voltage deviation between adjacent channels at the end of the preset test period. Indicates the maximum AC current deviation between adjacent synchronous acquisition channels at the end of the preset test period. Indicates the sine wave stability coefficient of the sine wave power supply within the preset working cycle. Indicates the test accuracy coefficient of the dielectric material to be tested at different preset frequencies. represents the test accuracy threshold range, It represents the current transformation ratio fraction of the rth synchronous acquisition channel at the end of the preset test period, Indicates the preset current transformation ratio fraction, Indicates the preset maximum AC voltage deviation, Indicates the preset maximum AC current deviation.

[0072] In this embodiment, the preset current transformation ratio fraction is usually set to 0.153%, the preset maximum AC voltage deviation is usually set to 0.2V, and the preset maximum AC current deviation is usually set to 0.2A; the test accuracy threshold range represents the range corresponding to the maximum and minimum values ​​of the historical test accuracy coefficients of the dielectric material to be tested at each historical frequency in the preset database.

[0073] It should be understood that the synchronization performance evaluation value decreases with the increase of the maximum AC voltage deviation and the maximum AC current deviation, and increases with the increase of the sine wave stability coefficient and the test accuracy coefficient. The synchronization performance evaluation value and the sine wave stability coefficient also indirectly affect the values ​​of the maximum AC voltage deviation and the maximum AC current deviation, specifically:

[0074] When the synchronization performance evaluation value increases, it means that the data acquisition and transmission process is more stable, making the waveform of the sinusoidal power supply output more stable, which helps to capture and record signal changes more accurately, that is, the sinusoidal wave stability coefficient also increases accordingly; when the sinusoidal wave stability coefficient increases, the frequency and amplitude of the sinusoidal wave signal are more stable, which helps to reduce the voltage and current deviations caused by signal fluctuations, thereby more accurately recording the changes in voltage and current, thereby reducing the range of maximum AC voltage deviation and maximum AC current deviation, because stable signals are easier to process synchronously, reducing synchronization errors caused by signal fluctuations.

[0075] There is a mutual influence relationship between the maximum AC voltage deviation and the maximum AC current deviation. When the power supply voltage is unstable, it will cause the current to change, and then produce voltage deviation and current deviation. For example, when the power supply voltage increases, the current may increase accordingly, resulting in an increase in current deviation. At the same time, due to the increase in voltage, the voltage deviation may also increase; conversely, when the power supply voltage decreases, the current may decrease, but the voltage deviation and current deviation may still be increased due to other factors (such as load).

[0076] By considering the above-mentioned indirect influence mechanisms and mutual influence mechanisms, it is helpful to understand the degree of change of the power supply interference ripple more comprehensively and clearly, and to achieve a more accurate evaluation of the synchronization accuracy and stability during the synchronous data acquisition process, thereby achieving an improvement in the low ripple anti-interference capability during the high-voltage frequency domain dielectric spectrum test, effectively solving the problem of low low ripple anti-interference capability during the high-voltage frequency domain dielectric spectrum test in the prior art.

[0077] Furthermore, the specific process of judging whether to send a power drive instruction based on the acquired synchronization performance evaluation value is as follows: judging whether the acquired synchronization performance evaluation value is greater than a preset synchronization performance evaluation value obtained from a preset database: if the acquired synchronization performance evaluation value is greater than the preset synchronization performance evaluation value obtained from the preset database, it indicates that the synchronization performance of the synchronization acquisition channel meets the expected synchronization performance requirements, and a power drive instruction is sent to the central control unit at this time; if the acquired synchronization performance evaluation value is not greater than the preset synchronization performance evaluation value obtained from the preset database, it indicates that the synchronization performance of the synchronization acquisition channel does not meet the expected synchronization performance requirements, and a power mode non-switching instruction is sent to the central control unit at this time; the power drive instruction is used to drive the step-up transformer after power amplification of the acquired digital signal to obtain a high-voltage and low-ripple variable-frequency power supply.

[0078] In this embodiment, the preset synchronization performance evaluation value is represented by the sum and average of the historical synchronization performance evaluation values ​​in the historical synchronization data collection process in the preset database; this example dynamically adjusts the power supply mode and test strategy by judging the numerical relationship between the synchronization performance evaluation value and the preset synchronization performance evaluation value, ensuring power driving and testing when the synchronization performance meets the requirements, thereby improving the efficiency and accuracy of the frequency domain dielectric spectrum test.

[0079] like Figure 3As shown, it is a flow chart of a high-voltage frequency domain dielectric spectrum testing method provided in an embodiment of the present application. A high-voltage frequency domain dielectric spectrum testing method provided in an embodiment of the present application includes the following steps: Step 1, initializing a sine wave power supply to obtain a sine wave stability coefficient, and judging whether to perform a frequency domain dielectric spectrum test based on the obtained sine wave stability coefficient. The sine wave stability coefficient is used to quantify the stability of the power ripple generated by the sine wave power supply within the expected working cycle; Step 2, real-time monitoring of the dielectric parameters of the dielectric material to be tested at different preset frequencies to obtain a test accuracy coefficient, and judging whether to perform synchronous data acquisition based on the obtained test accuracy coefficient. The test accuracy coefficient is used to quantify the reliability of the frequency domain dielectric spectrum test; Step 3, converting the operating parameters after synchronous acquisition into digital signals and storing them to obtain a synchronous performance evaluation value. The synchronous performance evaluation value is used to evaluate the synchronization performance of synchronous data acquisition; Step 4, judging whether to send a power drive instruction based on the obtained synchronization performance evaluation value. If so, the high-voltage isolation switch switches the power mode, otherwise a non-switching power mode instruction is sent.

[0080] like Figure 4 As shown, it is a specific flow chart of the frequency domain dielectric spectrum test of the transformer bushing provided in the embodiment of the present application. By comprehensively evaluating the sine wave stability, test accuracy, synchronization performance and intelligent power management strategy, the accuracy, synchronization and effectiveness of the frequency domain dielectric spectrum test are improved. These functions and advantages make the process have broad application prospects and important practical value in applications such as high-voltage frequency domain dielectric spectrum testing.

[0081] To summarize, the embodiment of the present application performs an initialization test on the sinusoidal wave power supply to obtain the sinusoidal wave stability coefficient and determine whether to perform the frequency domain dielectric spectrum test, then determines whether to perform synchronous data acquisition based on the obtained test accuracy coefficient, and finally determines whether to send a power drive instruction based on the obtained synchronization performance evaluation value. If so, the high-voltage isolation switch switches the power mode, otherwise a command not to switch the power mode is sent, thereby achieving improved accuracy and reliability of the frequency domain dielectric spectrum test, and further achieving improved low ripple anti-interference capability during the high-voltage frequency domain dielectric spectrum test, effectively solving the problem of low low ripple anti-interference capability during the high-voltage frequency domain dielectric spectrum test in the prior art.

[0082] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0083] The present invention is described with reference to flowcharts and / or block diagrams of systems, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0084] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0086] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0087] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A high voltage frequency domain dielectric spectrum testing system, characterized in that: include: High voltage power supply module, frequency domain dielectric spectrum test module, synchronous data acquisition module and low ripple variable frequency power supply module; The high-voltage power supply module is used to perform an initialization test on the sinusoidal power supply to obtain a sinusoidal wave stability coefficient, and determine whether to perform a frequency domain dielectric spectrum test based on the obtained sinusoidal wave stability coefficient, wherein the sinusoidal wave stability coefficient is used to quantify the stability of the power ripple generated by the sinusoidal wave power supply within the expected working cycle; The frequency domain dielectric spectrum test module is used to monitor the dielectric parameters of the dielectric material to be tested at different preset frequencies in real time to obtain a test accuracy coefficient, and to determine whether to perform synchronous data acquisition based on the obtained test accuracy coefficient, and the test accuracy coefficient is used to quantify the reliability of the frequency domain dielectric spectrum test; The synchronous data acquisition module is used to convert the operating parameters after synchronous acquisition into digital signals and store them to obtain a synchronous performance evaluation value, and the synchronous performance evaluation value is used to evaluate the synchronous performance of synchronous data acquisition; The low ripple variable frequency power supply module is used to determine whether to send a power drive instruction according to the acquired synchronization performance evaluation value, and if so, the high-voltage isolation switch switches the power mode, otherwise, a non-switching power mode instruction is sent; The specific steps for obtaining the sine wave stability coefficient are: When the obtained voltage peak value is within the allowable range of the voltage peak value obtained from the preset database and the output continuous current within the preset working cycle is equal to the preset output continuous current obtained from the preset database, real-time monitoring of the working state of the sine wave power supply within the preset working cycle; Obtain the sine wave distortion score of the sine wave signal at the current working moment, and simultaneously obtain and record the interference ripple on the sine wave signal to obtain the interference ripple amplitude score and the interference ripple frequency score, and obtain the sine wave stability coefficient in combination with the preset electromagnetic field interference factor obtained from the preset database; The sine wave distortion fraction represents the ratio of the harmonic component to the fundamental component; The interference ripple amplitude fraction represents the complement of the ratio of the interference ripple amplitude at the current working moment to the interference ripple amplitude at the previous working moment; The interference ripple frequency fraction represents the complement of the ratio of the interference ripple frequency at the current working moment to the interference ripple frequency at the previous working moment.

2. A high voltage frequency domain dielectric spectrum testing system as claimed in claim 1, characterized in that: The initialization test is used to monitor the interference of the sine wave power supply in a preset working cycle in real time; The frequency domain dielectric spectrum test is used to evaluate the insulation state and moisture content of the dielectric material to be tested; The dielectric parameters include insulation resistance, dielectric constant, dielectric loss factor, dielectric loss angle, and current amplitude and current phase flowing through the dielectric material to be tested; The operating parameters include active current, reactive current, AC voltage and AC current.

3. A high voltage frequency domain dielectric spectrum testing system as claimed in claim 1, characterized in that: The synchronous data acquisition module includes a central control unit, a high voltage power supply ADC acquisition unit and a dielectric current ADC acquisition unit to be measured; The central control unit is used to synchronously control the high-voltage power supply ADC acquisition unit and the dielectric current ADC acquisition unit to be measured, and store the acquired digital signals and receive power drive instructions and instructions not to switch power mode; The high-voltage power supply ADC acquisition unit is used to generate and adjust the high-voltage power supply applied to the dielectric material to be tested, and to measure and record the waveform and voltage parameters of the output voltage in real time, wherein the voltage parameters include voltage amplitude and voltage phase; The dielectric current ADC acquisition unit to be tested is used to measure and record the current in the current loop, and simultaneously collect and record the waveform and current parameters of the output current in real time. The current loop represents a loop in which the dielectric material to be tested is placed between a high voltage power supply and the ground. The current parameters include current amplitude and current phase.

4. A high voltage frequency domain dielectric spectrum testing system as claimed in claim 1, characterized in that: The specific limiting expression of the sine wave stability coefficient is: Where, t is the number of the current working moment in the preset working cycle, t = 1, 2, ..., T, T is the total number of the current working moments in the preset working cycle, e is a natural constant, SQN represents the sine wave stability coefficient of the sine wave power supply in the preset working cycle, μ represents the electromagnetic field interference factor, B t Represents the sine wave distortion fraction of the sine wave signal at the current working time t, R t It represents the interference ripple amplitude fraction of the sine wave signal at the current working time t, U t It represents the interference ripple frequency fraction of the sine wave signal at the current working time t, Y max It represents the voltage peak value of the sine wave power supply within the preset working cycle, ΔY represents the allowable range of the voltage peak value, AC represents the output continuous current of the sine wave power supply within the preset working cycle, and AC0 represents the preset output continuous current.

5. A high voltage frequency domain dielectric spectrum testing system as claimed in claim 1, characterized in that: The specific process of determining whether to perform the frequency domain dielectric spectrum test based on the obtained sine wave stability coefficient is as follows: Determine whether the obtained sine wave stability coefficient is within the sine wave stability threshold range obtained from the preset database. If so, perform the frequency domain dielectric spectrum test. Otherwise, do not perform the frequency domain dielectric spectrum test and prompt the preset personnel to perform maintenance. The test accuracy coefficient is obtained by the following method: When the obtained sine wave stability coefficient is within the sine wave stability threshold range obtained from the preset database, measuring and recording the measurement parameters of the dielectric material to be measured at each preset frequency, the measurement parameters including insulation resistance, dielectric constant, dielectric loss angle and dielectric loss factor; Obtaining the current amplitude coefficient and obtaining the test accuracy coefficient in combination with the reference measurement parameters obtained from the preset database; The current amplitude coefficient is obtained by processing the preset frequency, current amplitude, current phase and working time; The reference measurement parameters include reference insulation resistance, reference dielectric constant, reference dielectric loss angle, reference dielectric loss factor, reference insulation resistance deviation, reference dielectric constant deviation, reference dielectric loss angle deviation and reference dielectric loss factor deviation.

6. A high voltage frequency domain dielectric spectrum testing system as claimed in claim 1, characterized in that: The operation parameters after synchronous acquisition are converted into digital signals and stored, and before that, it also includes judging whether the channels of synchronous acquisition are qualified. The specific process includes: L1, numbering the four channels and performing a synchronous acquisition test, obtaining the response time of the four channels at the end of the synchronous acquisition test, wherein the four channels include a first synchronous acquisition channel, a second synchronous acquisition channel, a third synchronous acquisition channel and a fourth synchronous acquisition channel, and the response time of the four channels includes a first channel response time, a second channel response time, a third channel response time and a fourth channel response time; L2, determine whether the first channel response time is less than the preset first channel response time obtained from the preset database. If so, the first synchronous acquisition channel is recorded as a qualified channel and L3 is executed. Otherwise, the first synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to inspect the first synchronous acquisition channel; L3, determine whether the second channel response time is less than the preset second channel response time obtained from the preset database. If so, the second synchronous acquisition channel is recorded as a qualified channel and L4 is executed. Otherwise, the second synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to inspect the second synchronous acquisition channel; L4, determine whether the third channel response time is less than the preset third channel response time obtained from the preset database. If so, the third synchronous acquisition channel is recorded as a qualified channel and L5 is executed. Otherwise, the third synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to inspect the third synchronous acquisition channel. L5, determine whether the response time of the fourth channel is less than the preset response time of the fourth channel obtained from the preset database. If so, the fourth synchronous acquisition channel is recorded as a qualified channel and the qualified synchronous acquisition test is completed. Otherwise, the fourth synchronous acquisition channel is recorded as an unqualified channel and the preset personnel are prompted to inspect the fourth synchronous acquisition channel.

7. A high voltage frequency domain dielectric spectrum testing system as claimed in claim 1, characterized in that: The process of obtaining the synchronization performance evaluation value is as follows: E1, obtain the current transformation ratio score and determine whether the obtained current transformation ratio score is equal to the preset current transformation ratio score obtained from the preset database. If so, obtain the maximum AC voltage deviation and the maximum AC current deviation and execute E2, otherwise do not calculate the synchronization performance evaluation value and trigger the early warning mechanism; E2, when the maximum AC voltage deviation is not greater than the preset maximum AC voltage deviation obtained from the preset database and the maximum AC current deviation is not greater than the preset maximum AC current deviation obtained from the preset database, execute E3; E3, respectively denormalize the obtained maximum AC voltage deviation and the maximum AC current deviation, and combine the obtained sinusoidal wave stability coefficient and the test accuracy coefficient to obtain a synchronization performance evaluation value; The maximum AC voltage deviation represents the maximum value of the AC voltage deviation output between adjacent synchronous acquisition channels at the end of the preset test period; The maximum AC current deviation represents the maximum value of the AC current deviation outputted between adjacent synchronous acquisition channels at the end of the preset test period.

8. A high voltage frequency domain dielectric spectrum testing system as claimed in claim 3, characterized in that: The specific process of judging whether to send a power drive instruction according to the acquired synchronization performance evaluation value is as follows: Determine whether the obtained synchronization performance evaluation value is greater than the preset synchronization performance evaluation value obtained from the preset database: If the acquired synchronization performance evaluation value is greater than the preset synchronization performance evaluation value acquired from the preset database, a power driving instruction is sent to the central control unit; If the acquired synchronization performance evaluation value is not greater than the preset synchronization performance evaluation value acquired from the preset database, a non-switching power mode instruction is sent to the central control unit; The power drive instruction is used to drive a step-up transformer to obtain a high-voltage and low-ripple variable-frequency power supply after power amplification of the acquired digital signal.

9. A method for applying a high voltage frequency domain dielectric spectrum testing system as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Perform an initialization test on the sinusoidal power supply to obtain a sinusoidal wave stability coefficient, and determine whether to perform a frequency domain dielectric spectrum test based on the obtained sinusoidal wave stability coefficient, wherein the sinusoidal wave stability coefficient is used to quantify the stability of the power ripple generated by the sinusoidal wave power supply within an expected working cycle; Step 2: Real-time monitoring of dielectric parameters of the dielectric material to be tested at different preset frequencies to obtain a test accuracy coefficient, and judging whether to perform synchronous data acquisition based on the obtained test accuracy coefficient, wherein the test accuracy coefficient is used to quantify the reliability of the frequency domain dielectric spectrum test; Step 3, converting the operating parameters after synchronous acquisition into digital signals and storing them to obtain a synchronous performance evaluation value, wherein the synchronous performance evaluation value is used to evaluate the synchronous performance of synchronous data acquisition; Step 4: determine whether to send a power drive instruction based on the acquired synchronization performance evaluation value. If so, the high-voltage isolation switch switches the power mode. Otherwise, a non-switching power mode instruction is sent.

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