A high voltage electrical equipment online diagnosis system and method

Abstract

The present invention specifically relates to an online diagnosis system and method for high-voltage electrical equipment, including a signal acquisition system, a signal processing system and a signal evaluation system; the signal acquisition system is used to collect local discharge signals of high-voltage electrical equipment in real time and form a signal package file; the signal processing system is used to identify, read and process the fault characteristic signal file in the signal package file to form a data file; the signal evaluation system is used to further analyze and calculate the data file to obtain the local discharge parameters of the high-voltage electrical equipment, and compare the local discharge parameters of the high-voltage electrical equipment with the historical local discharge parameters of the high-voltage electrical equipment to determine the health status of the insulation performance of the high-voltage electrical equipment and obtain an evaluation result. The online diagnosis system and method for high-voltage electrical equipment of the present invention realizes sensitive and effective insulation detection and real-time monitoring of the health status of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage electrical insulation performance operation and maintenance, and in particular to an online diagnosis system and method for high-voltage electrical equipment. Background Art

[0002] The insulation strength of the insulation materials of high-voltage electrical equipment gradually decreases and eventually breaks down due to electrical aging, thermal aging, mechanical aging, and environmental aging. If not handled in time, it will develop into a short-circuit fault, seriously damage the equipment, and even expand into a vicious accident. For this reason, the industry has attached great importance to electrical insulation. The traditional method is mainly to detect through the insulation performance test of high-voltage electrical equipment. At present, the mature applications are all offline tests and tests, such as: insulation test, dielectric loss test, DC withstand voltage test, AC withstand voltage test, offline partial discharge test, etc. There are also some power supply equipment, in order to achieve insulation fault protection for online equipment as much as possible, by measuring leakage current or installing leakage current protection, grounding protection, short-circuit protection, etc. to protect the insulation fault of the equipment as much as possible, but this kind of protection and measurement is a macroscopic, stable and serious insulation fault for electrical insulation faults, and cannot respond to the early abnormalities of insulation aging. When the insulation is damaged to the extent of protection action, the result is that the equipment is severely damaged and cannot continue to operate through simple treatment, and the production system basically develops into an accident. Summary of the invention

[0003] Based on this, it is necessary to provide an online diagnosis system and method for high-voltage electrical equipment to address the problems that the insulation protection of existing online high-voltage electrical equipment cannot achieve sensitive and effective insulation detection and offline tests cannot monitor the health status of equipment in real time. The system and method can achieve sensitive and effective insulation detection and real-time monitoring of the health status of equipment.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] An online diagnosis system for high-voltage electrical equipment, comprising a signal acquisition system, a signal processing system and a signal evaluation system;

[0006] The signal acquisition system is used to collect local discharge signals of high-voltage electrical equipment in real time and form a signal package file; the signal processing system is used to identify, read and process the fault characteristic signal file in the signal package file to form a data file;

[0007] The signal evaluation system is used to further analyze and calculate the data file to obtain the local discharge parameters of the high-voltage electrical equipment, and compare the local discharge parameters of the high-voltage electrical equipment with the historical local discharge parameters of the high-voltage electrical equipment to determine the health status of the insulation performance of the high-voltage electrical equipment and obtain evaluation results.

[0008] Furthermore, the local discharge signal of the high-voltage electrical equipment is an insulation characteristic waveform of the high-voltage electrical equipment.

[0009] Furthermore, the insulation characteristic waveform of the high-voltage electrical equipment is a superposition of a fundamental waveform of the voltage of the high-voltage electrical equipment and a partial discharge pulse waveform.

[0010] Furthermore, the local discharge pulse waveform of the high-voltage electrical equipment includes a local discharge voltage waveform measured by a coupling capacitor, a local discharge current waveform measured by a current transformer, or a local discharge vibration waveform measured by a vibration probe, and the coupling capacitor, current transformer and vibration probe are all arranged at the incoming terminal, busbar or switch of the high-voltage electrical equipment.

[0011] Furthermore, the signal processing system processes the fault characteristic signal file in the signal package file including digital display, waveform display, FFT analysis, wavelet analysis, fundamental spectrum analysis, decibel analysis, storage, and sampling rate adjustment.

[0012] Furthermore, the signal processing system obtains a purified partial discharge pulse waveform by calling Matlab software wavelet analysis on the partial discharge pulse waveform of the high-voltage electrical equipment; and superimposes the purified partial discharge pulse waveform on the fundamental waveform of the voltage of the high-voltage electrical equipment as a comparison benchmark.

[0013] Furthermore, the fault characteristic signal of the high-voltage electrical equipment includes a partial discharge pulse signal of the high-voltage electrical equipment, a phase of a basic voltage of a power supply of the high-voltage electrical equipment, and an interruption time of a pulse signal of the high-voltage electrical equipment.

[0014] Furthermore, the signal evaluation system is used to compare the initiation voltage Ui and extinction voltage Ue of partial discharge of high-voltage electrical equipment with historical parameters of the high-voltage electrical equipment, determine the health status of the insulation performance of the high-voltage electrical equipment, and obtain evaluation results.

[0015] Furthermore, the evaluation result evaluates the health status level of the insulation according to the percentage of the phase interruption time t of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment to the voltage cycle time.

[0016] Furthermore, the health status of the insulation performance of the high-voltage electrical equipment includes an initial stage, a stable stage, a starting partial discharge stage, an obvious partial discharge stage and an insulation failure stage. The partial discharge amount in the obvious partial discharge stage sets different insulation failure alarm intervals according to different insulation materials.

[0017] Furthermore, the starting voltage Ui and the extinction voltage Ue of the partial discharge pulse waveform of the high-voltage electrical equipment are obtained by calculating the extinction time of the partial discharge pulse in each cycle by monitoring the moment of the pulse on the power frequency voltage curve of the winding.

[0018] Furthermore, for parameters with ready-made measurement standards, the evaluation criteria are based on the ready-made measurement standards; for parameters without ready-made measurement standards, when conducting evaluation, the benchmark database is determined according to the corresponding historical parameter change trends of the equipment itself. For the first time when the equipment is put into operation, the offline detection results are used to adjust the basic recommended alarm values ​​and outage maintenance values. Subsequently, artificial intelligence deep learning can be used to perfect and improve the recommended alarm values ​​and outage maintenance values.

[0019] A method for online diagnosis of high voltage electrical equipment comprises the following steps:

[0020] 1. Collect partial discharge signals of high-voltage electrical equipment and form signal package files;

[0021] 2. Identify, read and process the fault characteristic signal files in the signal package files, form data files and establish a database;

[0022] 3. Further analyze and calculate the database file to obtain the partial discharge parameters of the high-voltage electrical equipment, and compare the partial discharge parameters of the high-voltage electrical equipment with the historical partial discharge parameters of the high-voltage electrical equipment to determine the health status of the insulation performance of the high-voltage electrical equipment and obtain the evaluation results.

[0023] The online diagnosis system and method for high-voltage electrical equipment of the present invention is based on online partial discharge monitoring and diagnosis of high-voltage electrical equipment, and is based on not affecting the structure of existing systems and equipment, to achieve the goal of remote diagnosis and predictive maintenance of the insulation performance of high-voltage electrical equipment, and well solves the problems that cannot be solved by current offline tests and online protection, thereby ensuring that the insulation status of the equipment is knowable and controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the equivalent circuit diagram of insulation partial discharge;

[0025] Figure 2 It is the relationship curve between partial discharge voltage and maximum charge;

[0026] Figure 3 It is a schematic diagram of the partial discharge pulse waveform acquisition method of high-voltage electrical equipment;

[0027] Figure 4 This is a schematic diagram of the partial discharge pulse waveform of high-voltage electrical equipment after wavelet analysis using Matlab software;

[0028] Figure 5 This is a partial discharge trend diagram of high-voltage electrical equipment.

[0029] Figure 1 In the figure, C1 is the equivalent capacitance of the normal insulating vertical surface; CV is the equivalent capacitance of the vertical surface with the air bubble, and Ca is the capacitance of the air bubble.

[0030] Figure 3 The solid line in the middle marks the loop of the partial discharge voltage waveform measured by the coupling capacitor, the dotted line marks the loop of the partial discharge vibration waveform measured by the vibration probe, and the dot-dash line marks the loop of the partial discharge current waveform measured by the current transformer.

[0031] Figure 4 Where t is the time interval between the partial discharge extinction voltage Ue and the starting voltage Ui in the fundamental voltage waveform phase.

[0032] Figure 5 In the figure, 1 is the initial stage; 2 is the stable stage; 3 is the beginning of partial discharge stage; 4 is the obvious partial discharge stage; and 5 is the insulation failure stage. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] See also Figure 1 If there are air bubbles in the insulation material inside the high-voltage electrical equipment, since the insulation strength of air is lower than that of vacuum, as the voltage increases, the air bubbles are first broken down, resulting in discharge inside the high-voltage electrical equipment. As the insulation material is stimulated by various aging factors, the insulation strength will gradually decrease, the discharge site will gradually expand, and finally develop into insulation breakdown. Therefore, it is necessary to monitor the local discharge amount and discharge location of high-voltage electrical equipment as early as possible, and to repair and handle it in time to avoid accidents. However, when the discharge begins, the discharge amount is very small and difficult to measure and locate.

[0035] In actual production, due to different dielectric constants and insulation strengths of different insulating media, voltage breakdown will not occur on the same vertical line under normal insulation strength. Once a material with lower insulation strength is mixed in, the voltage shared by it will decrease, causing the overall insulation strength of the same vertical line to decrease, resulting in voltage breakdown at the weak insulation strength point, i.e., partial discharge.

[0036] In addition, since the amplitude of the AC voltage changes in a waveform, when the insulation strength does not drop too seriously, local discharge will occur in the form of intermittent pulse discharge, which will first occur near the voltage peak and trough, and the local discharge will stop when it returns to near the zero point.

[0037] The insulation state of high-voltage electrical equipment is usually expressed by the following characteristic quantities: ① partial discharge amount and discharge location; ② dielectric loss factor (tgδ); ③ leakage current; ④ equipment capacitance change.

[0038] For solid insulating materials of electrical equipment, partial discharge generally occurs at locations where dielectric insulation is uneven. Due to excessive local electric field strength, the breakdown occurs. In the early stages of a fault, it manifests as a local breakdown and does not cause the breakdown of the entire insulation structure. This discharge manifests as a pulse with a duration of less than 1μs. Generally, the frequency of partial discharge is around 30Mz (the specific frequency is related to the insulating material). Under the same operating voltage, the weaker the insulation strength, the earlier and more severe the discharge.

[0039] Online diagnosis of insulation faults is done by monitoring the strength of partial discharge to diagnose the health of the insulation.

[0040] See also Figure 2 When the insulation layer is aged and degraded, it can be detected by the traditional offline partial discharge test (corona test). The evaluation criteria are: maximum discharge Q m The curve increases slowly as the voltage increases. For the same electrical equipment, under the same power supply voltage and within the same time interval, the more partial discharge pulses there are, the larger the discharge pulse amplitude is, and the discharge quantity Q m The starting voltage of partial discharge is V i Directly reflects the dielectric strength of the insulating material, the slope of the curve K i It is related to the degree of insulation material degradation. The maximum discharge capacity Q m Related to the capacitance of the insulating material. is the local maximum discharge Q m The corresponding voltage. However, this method is easier to implement in offline partial discharge tests, but it is not suitable for online partial discharge detection technology.

[0041] In the online partial discharge test, the typical partial discharge fault characteristics are: starting voltage U i The amplitude of the voltage Ue decreases with the severity of insulation degradation, and the amplitude of the extinction voltage Ue also decreases with the severity of insulation degradation. However, since the partial discharge signal is a small signal of ultra-high frequency, it is easily interfered by external noise, which makes it difficult to detect and identify. Therefore, although the insulation offline diagnosis theory is relatively mature, the insulation online diagnosis has been difficult to promote and apply.

[0042] The present invention provides an online diagnosis system for high-voltage electrical equipment, including a signal acquisition system, a fault characteristic signal collection and analysis system, and a state evaluation and prediction system;

[0043] The signal acquisition system is used to collect local discharge signals of high-voltage electrical equipment in real time and form a signal package file; the signal processing system is used to identify, read and process the fault characteristic signal file in the signal package file, form a data file, and establish a database;

[0044] The signal evaluation system is used to further analyze and calculate the database file to obtain the local discharge parameters of the high-voltage electrical equipment, and compare the local discharge parameters of the high-voltage electrical equipment with the historical local discharge parameters of the high-voltage electrical equipment to determine the health status of the insulation performance of the high-voltage electrical equipment and obtain evaluation results.

[0045] Furthermore, the local discharge signal of the high-voltage electrical equipment is an insulation characteristic waveform of the high-voltage electrical equipment.

[0046] Furthermore, the insulation characteristic waveform of the high-voltage electrical equipment is a superposition of a fundamental waveform of the voltage of the high-voltage electrical equipment and a partial discharge pulse waveform.

[0047] In view of the particularity of the partial discharge signal, the partial discharge signal of the high-voltage electrical equipment is collected by a sensor with high frequency, high saturation response capability, high resolution and high sensitivity.

[0048] Further, see Figure 3 The partial discharge pulse waveform of the high-voltage electrical equipment includes the partial discharge voltage waveform measured by the coupling capacitor, the partial discharge current waveform measured by the current transformer, or the partial discharge vibration waveform measured by the vibration probe. The loops entering the signal acquisition system include the following three loops: the solid line marks the loop of the partial discharge voltage waveform measured by the coupling capacitor, the dotted line marks the loop of the partial discharge vibration waveform measured by the vibration probe, and the dot-dash line marks the loop of the partial discharge current waveform measured by the current transformer.

[0049] The partial discharge voltage waveform measured by the coupling capacitor, the partial discharge current waveform measured by the current transformer, and the partial discharge vibration waveform measured by the vibration probe are directly filtered without wavelet analysis. The partial discharge pulse waveform obtained will appear to be a relatively messy waveform with certain regular characteristics due to the existence of white noise. The partial discharge voltage waveform measured by the coupling capacitor is directly filtered without wavelet analysis. The partial discharge pulse waveform obtained will appear to be a relatively messy waveform with certain regular characteristics due to the existence of white noise.

[0050] Furthermore, the signal processing system processes the fault characteristic signal file in the signal package file including digital display, waveform display, FFT analysis, wavelet analysis, fundamental spectrum analysis, decibel analysis, storage, and sampling rate adjustment.

[0051] Further, see Figure 4 The signal processing system uses Matlab software to analyze the partial discharge pulse waveform of the high-voltage electrical equipment by wavelet analysis to obtain a cleaner and neater waveform; and uses the fundamental waveform of the voltage of the high-voltage electrical equipment as a comparison benchmark to superimpose the purified partial discharge pulse waveform.

[0052] Furthermore, the fault characteristic signal of the high-voltage electrical equipment includes a partial discharge pulse signal of the high-voltage electrical equipment, a phase of a basic voltage of a power supply of the high-voltage electrical equipment, and an interruption time of a pulse signal of the high-voltage electrical equipment.

[0053] Combined with the theoretical analysis above, it can be seen that electrical insulation faults begin to produce partial discharge when the applied voltage rises to a certain value, and as the voltage rises or the insulation deteriorates, the partial discharge intensifies and the discharge power increases. The discharge power formula is as follows:

[0054]

[0055] Where, T ref is the reference time interval; q i is a single apparent charge; P is the charge at the selected reference time interval T ref The single apparent charge q i The average pulse power fed into the test object at both ends; u i is a single apparent charge q i The corresponding discharge instant t i The instantaneous value of the test voltage; i is a natural number.

[0056] The comprehensive judgment standard for insulation of ordinary high-voltage AC motors is as follows in Table 1:

[0057] Table 1 Comprehensive judgment standard for insulation of ordinary high-voltage AC motors

[0058]

[0059] In actual production operation, it is not easy to measure the discharge power online. The partial discharge characteristics of the insulation of the present invention can identify the degree of degradation of the insulation strength through the components or positions of the fundamental wave and the pulse waveform of the partial discharge.

[0060] Furthermore, the signal evaluation system is used to compare the pulse position of the partial discharge of the high-voltage electrical equipment with the historical parameters of the high-voltage electrical equipment, determine the health status of the insulation performance of the high-voltage electrical equipment, and obtain an evaluation result.

[0061] For example, when the power supply voltage is stable and the partial discharge is not seriously broken down, the relationship between the number of pulses and the time of the partial discharge of the power supply fundamental wave is determined, so the severity of the partial discharge can be monitored by monitoring the starting voltage Ui and the extinction voltage Ue of the partial discharge pulse. This diagnostic result can more accurately assess the severity of the insulation deterioration of the equipment. The insulation strength given here can only be a relative value, and an accurate evaluation must be given based on the relevant historical parameters of the equipment.

[0062] Furthermore, the starting voltage Ui and the extinction voltage Ue of the partial discharge pulse waveform of the high-voltage electrical equipment are obtained by calculating the extinction time of the partial discharge pulse in each cycle by monitoring the moment of the pulse on the power frequency voltage curve of the winding.

[0063] Furthermore, for parameters with ready-made measurement standards, based on the ready-made evaluation standards; for parameters without ready-made measurement standards, these parameters can basically be defined as equipment characteristic parameters. When conducting the evaluation, it is also necessary to determine the benchmark database based on the corresponding historical parameter change trends of the equipment itself. For the first time commissioning, it is also necessary to make full use of the offline detection results to adjust the basic recommended alarm values ​​and shutdown maintenance values. Subsequently, artificial intelligence deep learning can be used to perfect and improve key sensitive parameters such as recommended alarm values ​​and shutdown maintenance values, so as to make the evaluation of the health status of the motor more accurate and effective.

[0064] Furthermore, the evaluation result evaluates the health status of the insulation according to the percentage of the phase interruption time t of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment in the voltage cycle time. Due to different insulation materials, this evaluation standard will be slightly different, and generally needs to be compared with the pressure parameter. Generally, this percentage of insulation materials is controlled at 25% to 30%, and it is qualified if it is greater than 25% to 30%.

[0065] See also Figure 5 The health status of the insulation performance of the high-voltage electrical equipment is divided into five stages, namely, initial stage 1, stable stage 2, beginning partial discharge stage 3, obvious partial discharge stage 4 and insulation failure stage 5, by the amount of partial discharge generated. Among them, the amount of partial discharge in the obvious partial discharge stage will set different insulation failure alarm intervals due to different insulation materials.

[0066] The present invention also provides a method for online diagnosis of high-voltage electrical equipment, comprising the following steps:

[0067] 1. Collect partial discharge signals of high-voltage electrical equipment and form signal package files;

[0068] 2. Identify, read and process the fault characteristic signal files in the signal package files, form data files and establish a database;

[0069] 3. Further analyze and calculate the database file to obtain the partial discharge parameters of the high-voltage electrical equipment, and compare the partial discharge parameters of the high-voltage electrical equipment with the historical partial discharge parameters of the high-voltage electrical equipment to determine the health status of the insulation performance of the high-voltage electrical equipment and obtain the evaluation results.

[0070] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An online diagnostic system for high voltage electrical equipment, characterized in that: Including signal acquisition system, signal processing system and signal evaluation system; The signal acquisition system is used to collect local discharge signals of high-voltage electrical equipment in real time online and form a signal package file; the local discharge signal of the high-voltage electrical equipment is an insulation characteristic waveform of the high-voltage electrical equipment; the insulation characteristic waveform of the high-voltage electrical equipment is a superposition of the fundamental waveform of the voltage of the high-voltage electrical equipment and the partial discharge pulse waveform; the local discharge pulse waveform of the high-voltage electrical equipment includes a local discharge voltage waveform measured by a coupling capacitor, a local discharge current waveform measured by a current transformer, or a local discharge vibration waveform measured by a vibration probe; The signal processing system is used to identify, read and process the fault characteristic signal file in the signal package file to form a data file; the fault characteristic signal includes a partial discharge pulse signal of the high-voltage electrical equipment, a phase of the basic voltage of the power supply of the high-voltage electrical equipment and an interruption time of the pulse signal of the high-voltage electrical equipment; The signal evaluation system is used to further analyze and calculate the data file, obtain the phase of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment in the fundamental voltage circuit, and compare the phase of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment in the fundamental voltage circuit with the historical corresponding parameters of the high-voltage electrical equipment, judge the health status of the insulation performance of the high-voltage electrical equipment, and obtain the evaluation result; The evaluation result evaluates the health status of the insulation according to the percentage of the phase interruption time t of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment to the voltage cycle time; The health status of the insulation performance of the high-voltage electrical equipment includes an initial stage, a stable stage, a starting partial discharge stage, an obvious partial discharge stage and an insulation failure stage. The partial discharge amount in the obvious partial discharge stage sets different insulation failure alarm intervals according to different insulation materials.

2. The high-voltage electrical equipment online diagnostic system according to claim 1, characterized in that: The coupling capacitor, current transformer and vibration probe are all arranged at the incoming line terminal, busbar or switch of the high-voltage electrical equipment.

3. The high-voltage electrical equipment online diagnostic system according to claim 1, characterized in that: The signal processing system processes the fault characteristic signal file in the signal package file including digital display, waveform display, FFT analysis, wavelet analysis, fundamental wave spectrum analysis, decibel analysis, phase analysis, storage and sampling rate adjustment.

4. The high-voltage electrical equipment online diagnosis system according to claim 3, characterized in that: The signal processing system obtains a purified partial discharge pulse waveform by calling Matlab software wavelet analysis on the partial discharge pulse waveform of the high-voltage electrical equipment; and superimposes the purified partial discharge pulse waveform on the basis of the fundamental waveform of the voltage of the high-voltage electrical equipment.

5. The high-voltage electrical equipment online diagnostic system according to claim 1, characterized in that: The starting voltage Ui and the extinction voltage Ue of the partial discharge pulse waveform of the high-voltage electrical equipment are obtained by calculating the extinction time of the partial discharge pulse in each cycle by monitoring the phase moment of the pulse on the power frequency voltage curve of the winding.

6. The high-voltage electrical equipment online diagnostic system according to claim 1, characterized in that: For parameters with ready-made measurement standards, the evaluation is based on the ready-made evaluation standards. For parameters without ready-made measurement standards, when conducting the evaluation, the benchmark database is determined according to the corresponding historical parameter change trends of the equipment itself. When it is first put into operation, the offline detection results are used to adjust the basic recommended alarm values ​​and outage maintenance values. Subsequently, artificial intelligence deep learning is used to perfect and improve the recommended alarm values ​​and outage maintenance values.

7. A method for online diagnosis of high voltage electrical equipment, characterized in that: The steps include: Step 1, real-time online acquisition of partial discharge signals of high-voltage electrical equipment and forming a signal package file; the partial discharge signal of the high-voltage electrical equipment is a characteristic waveform of the insulation of the high-voltage electrical equipment; the characteristic waveform of the insulation of the high-voltage electrical equipment is a superposition of a fundamental waveform of the voltage of the high-voltage electrical equipment and a partial discharge pulse waveform; the partial discharge pulse waveform of the high-voltage electrical equipment includes a partial discharge voltage waveform measured by a coupling capacitor, a partial discharge current waveform measured by a current transformer, or a partial discharge vibration waveform measured by a vibration probe; Step 2, identifying, reading and processing the fault characteristic signal file in the signal package file to form a data file; the fault characteristic signal includes a partial discharge pulse signal of the high-voltage electrical equipment, a phase of a basic voltage of a power supply of the high-voltage electrical equipment, and an intermittent time of a pulse signal of the high-voltage electrical equipment; Step 3: further analyze and calculate the data file to obtain the phase of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment in the fundamental voltage circuit, and compare the phase of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment in the fundamental voltage circuit with the historical corresponding parameters of the high-voltage electrical equipment to determine the health status of the insulation performance of the high-voltage electrical equipment and obtain the evaluation results; The evaluation result evaluates the health status of the insulation according to the percentage of the phase interruption time t of the starting voltage Ui and the extinction voltage Ue of the partial discharge of the high-voltage electrical equipment to the voltage cycle time; The health status of the insulation performance of the high-voltage electrical equipment includes an initial stage, a stable stage, a starting partial discharge stage, an obvious partial discharge stage and an insulation failure stage. The partial discharge amount in the obvious partial discharge stage sets different insulation failure alarm intervals according to different insulation materials.

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