Intermittent Partial Discharge Insulation Defect Detection System and Partial Discharge Simulation Method

Abstract

The present invention discloses an intermittent partial discharge insulation defect detection system. The center of the test pot insulator and the reference pot insulator is fixedly penetrated on a metal guide rod. The top end of the metal guide rod passes through the top end of the discharge defect simulation tank and is fixedly connected to the incoming line bushing. The ultrasonic sensor is installed on the outer surface of the discharge defect simulation tank, and the UHF sensor is installed on the inner surface of the discharge defect simulation tank. The voltage signal output end of the non-partial discharge pressurization module is connected to the metal guide rod, the pulse current signal output end of the non-partial discharge pressurization module is connected to the host computer, the test pot insulator is connected to the host computer through a detection impedance, the ultrasonic signal output end of the ultrasonic sensor is connected to the host computer, the UHF signal output end of the UHF sensor is connected to the host computer, and the AC phase signal output end of the non-partial discharge pressurization module is connected to the host computer. The present invention can effectively detect the weak partial discharge characteristic signal and effectively simulate the intermittent partial discharge.

Description

Technical Field

[0001] The present invention relates to the technical field of insulation condition detection of power equipment, and specifically refers to an intermittent partial discharge insulation defect detection system and a partial discharge simulation method. Background Art

[0002] Gas-insulated switchgear (GIS) is a core power equipment of the national power grid. It has the advantages of high value and small floor area, and is an essential equipment for high-voltage substations in China's power grid system. Once damaged, it will seriously affect the reliability of power supply in a large area. GIS generally uses SF6 gas as the insulating medium. The SF6 insulating gas can effectively improve the insulation ability of GIS. However, insulation defects will inevitably be introduced during production, installation, maintenance and operation, inducing the occurrence of partial discharge. Partial discharge is similar to a "malignant tumor" in the insulation system of GIS. If the partial discharge insulation defect is not detected by detection technology before it evolves into breakdown discharge, the partial discharge insulation defect will gradually evolve into breakdown discharge, resulting in the outage and damage of GIS. Therefore, it is necessary to use effective detection technology to achieve the effective detection of partial discharge insulation defects.

[0003] Currently, the detection technologies commonly used for partial discharge insulation defects in GIS include the ultra-high frequency method, the ultrasonic method, the high-frequency current method, the optical detection method, etc. These methods can already achieve the effective detection of stable partial discharge insulation defects. However, there is currently no effective detection means for intermittent partial discharge insulation defects. This is because there is a lack of an effective intermittent discharge simulation method, resulting in the unclear understanding of the discharge mechanism and its discharge characteristics of intermittent partial discharge. In particular, there is a lack of a simulation method for effectively simulating the process of intermittent discharge evolving into breakdown discharge. Summary of the Invention

[0004] The purpose of the present invention is to provide an intermittent partial discharge insulation defect detection system and a partial discharge simulation method. The present invention can effectively achieve the effective detection of weak partial discharge characteristic signals and the effective simulation of intermittent partial discharge, providing reliable technical support for the understanding of the discharge mechanism and discharge characteristics of intermittent partial discharge insulation defects in GIS, as well as the effective detection of intermittent partial discharge insulation defects.

[0005] To achieve this purpose, the intermittent partial discharge insulation defect detection system designed by the present invention is characterized in that it includes a non-partial discharge pressurization module, a partial discharge defect model of GIS, and a host computer;

[0006] The partial discharge defect model of the gas-insulated switchgear includes a discharge defect simulation tank, a test pot insulator, a reference pot insulator, a metal guide rod, an inlet bushing, an ultrasonic sensor, and a UHF sensor. Among them, the centers of the test pot insulator and the reference pot insulator are fixedly penetrated on the metal guide rod. The test pot insulator and the reference pot insulator are both located inside the discharge defect simulation tank. The top of the metal guide rod passes through the top of the discharge defect simulation tank and is fixedly connected to the inlet bushing. The ultrasonic sensor is installed on the outer surface of the discharge defect simulation tank, and the UHF sensor is a flexible two-dimensional structure installed on the inner surface of the discharge defect simulation tank;

[0007] The voltage signal output terminal of the non-partial discharge pressurizing module is connected to the metal guide rod through the inlet bushing. The pulse current signal output terminal of the non-partial discharge pressurizing module is connected to the first input terminal of the pulse current signal of the host. The test pot insulator is connected to the second input terminal of the pulse current signal of the host through the detection impedance Z2. The reference pot insulator is connected to the third input terminal of the pulse current signal of the host through the detection impedance Z3. The ultrasonic signal output terminal of the ultrasonic sensor is connected to the ultrasonic signal input terminal of the host. The UHF signal output terminal of the UHF sensor is connected to the UHF signal input terminal of the host. The AC phase signal output terminal of the non-partial discharge pressurizing module is connected to the AC phase signal input terminal of the host.

[0008] The present invention can effectively detect the weak partial discharge characteristic signals and effectively simulate the intermittent partial discharge, providing reliable technical support for understanding the discharge mechanism and discharge characteristics of the intermittent partial discharge insulation defect of the gas-insulated switchgear, as well as the effective detection of the intermittent partial discharge insulation defect. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic structural diagram of the present invention;

[0010] Figure 2 is a flowchart of the method for collecting the insulation defect characteristic signals in the present invention;

[0011] Figure 3 is a flowchart of the method for simulating the insulation defect of the intermittent partial discharge evolving into a breakdown discharge in the present invention.

[0012] Among them, 1 - non-partial discharge pressurizing module, 2 - partial discharge defect model of the gas-insulated switchgear, 2.1 - discharge defect simulation tank, 2.2 - test pot insulator, 2.3 - reference pot insulator, 2.4 - metal guide rod, 2.5 - inlet bushing, 2.6 - ultrasonic sensor, 2.7 - UHF sensor, 3 - vibration platform, 3.1 - programmable motor, 3.2 - transmission shaft, 3.3 - vibration plate, 4 - host. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0014] As Figure 1 shown in the intermittent partial discharge insulation defect detection system, which includes a non-partial discharge pressurization module 1, a gas-insulated switchgear partial discharge defect model 2, and a host 4;

[0015] The gas-insulated switchgear partial discharge defect model 2 includes a discharge defect simulation tank 2.1, a test pothead insulator 2.2, a reference pothead insulator 2.3, a metal guide rod 2.4, an inlet bushing 2.5, an ultrasonic sensor 2.6, and a UHF sensor 2.7. Among them, the centers of the test pothead insulator 2.2 and the reference pothead insulator 2.3 are fixedly penetrated on the metal guide rod 2.4. The test pothead insulator 2.2 and the reference pothead insulator 2.3 are both located inside the discharge defect simulation tank 2.1. The top of the metal guide rod 2.4 passes through the top of the discharge defect simulation tank 2.1 and is fixedly connected to the inlet bushing 2.5. The ultrasonic sensor 2.6 is installed on the outer surface of the discharge defect simulation tank 2.1, and the UHF sensor 2.7 is installed on the inner surface of the discharge defect simulation tank 2.1;

[0016] The voltage signal output end of the non-partial discharge pressurization module 1 is connected to the metal guide rod 2.4 through the inlet bushing 2.5. The pulse current signal output end of the non-partial discharge pressurization module 1 is connected to the first pulse current signal input end of the host 4. The test pothead insulator 2.2 is connected to the second pulse current signal input end of the host 4 through the detection impedance Z2. The reference pothead insulator 2.3 is connected to the third pulse current signal input end of the host 4 through the detection impedance Z3. The ultrasonic signal output end of the ultrasonic sensor 2.6 is connected to the ultrasonic signal input end of the host 4. The UHF signal output end of the UHF sensor 2.7 is connected to the UHF signal input end of the host 4. The AC phase signal output end of the non-partial discharge pressurization module 1 is connected to the AC phase signal input end of the host 4. The AC phase signal provides power frequency AC phase information for the pulse current signal. By observing the frequency of the pulse current signal appearing at different phases, it can be judged whether it is intermittent or stable discharge. The UHF sensor 2.7 outputs electromagnetic wave signals in the range of 300M to 3GHz. The frequency range of the electromagnetic interference wave signals in the power field is generally below 300MHz. Collecting electromagnetic wave signals above 300MHz can effectively reflect the partial discharge defects of the equipment and improve the sensitivity and anti-interference ability of the entire system.

[0017] In the above technical solution, it further includes a vibration platform 3. The vibration platform 3 is used to apply a vibration signal to the partial discharge defect model 2 of the gas-insulated switchgear, simulate the vibration impact on the gas-insulated switchgear during the opening or closing process of the circuit breaker switch in the gas-insulated switchgear, and simulate the actual vibration situation generated during the operation of the gas-insulated switchgear. Since there is a circuit breaker inside the gas-insulated switchgear in on-site operation, the vibration of the circuit breaker during its operation (opening / closing) will cause vibration to the gas-insulated switchgear itself. And the partial discharge insulation defect itself is affected by vibration, and its discharge characteristics may change. For example, in the case of a metal particle insulation defect, the metal particles will move under vibration, resulting in a change in the partial discharge characteristics generated by the metal particle insulation defect. Therefore, in order to more accurately simulate the partial discharge characteristics in the on-site gas-insulated switchgear, it is necessary to add an environmental condition that can simulate the on-site vibration to the test simulation platform.

[0018] In the above technical solution, the vibration platform 3 includes a programmable motor 3.1, a transmission shaft 3.2, and a vibration plate 3.3. The output shaft of the programmable motor 3.1 is connected to the vibration plate 3.3 through the transmission shaft 3.2. The programmable motor 3.1 is used to drive the vibration plate 3.3 to vibrate through the transmission shaft 3.2. The discharge defect simulation tank 2.1 is placed on the vibration plate 3.3. The vibration of the gas-insulated switchgear in on-site operation is integral, so it is necessary to place the simulation platform as a whole on the entire vibration plate. The programmable motor is used because the on-site vibration of the gas-insulated switchgear has its own law, and the vibration law needs to be realized by programming the programmable motor.

[0019] In the above technical solution, the non-partial discharge pressurization module (1) includes a voltage regulator table T1, a step-up transformer T2, a current-limiting resistor Rr, capacitors C1 to C3, and a detection impedance Z1. The input end of the voltage regulator table T1 is connected to the current and voltage AC. One end of the primary of the step-up transformer T2 is connected to the voltage regulating resistor of the voltage regulator table T1, and the other end of the primary of the step-up transformer T2 is connected to the voltage regulating tap of the voltage regulator table T1. One end of the secondary of the step-up transformer T2 is connected to one end of the current-limiting resistor Rr, and the other end of the current-limiting resistor Rr is the voltage signal output end of the non-partial discharge pressurization module 1. One end of the capacitor C3 is connected to the other end of the current-limiting resistor Rr, and the other end of the capacitor C3 is connected to one end of the detection impedance Z1. The other end of the secondary of the step-up transformer T2 is connected to the other end of the detection impedance Z1, and the other end of the secondary of the step-up transformer T2 is grounded;

[0020] One end of the capacitor C1 is connected to the other end of the current-limiting resistor Rr, the other end of the capacitor C1 is connected to one end of the capacitor C2, and the other end of the capacitor C2 is connected to the other end of the detection impedance Z1. The other end of the capacitor C1 is the AC phase signal output end of the non-partial discharge pressurization module 1;

[0021] One end of the detected impedance Z1 is the pulse current signal output end of the non - partial - discharge voltage - applying module 1.

[0022] In the above - mentioned technical solution, the non - partial - discharge voltage - applying module 1 further includes a voltmeter V. One end of the voltmeter V is connected to one end of the capacitor C2, and the other end of the voltmeter V is connected to the other end of the secondary of the step - up transformer T2.

[0023] In the above - mentioned technical solution, both the test pot - type insulator 2.2 and the reference pot - type insulator 2.3 are grounded, and the test pot - type insulator 2.2 and the reference pot - type insulator 2.3 can be in different experimental intervals. Being in different experimental intervals is to simulate two identical test environments. In this way, if there are external interference signals, the pulse current signals corresponding to these two intervals will show the same time - domain characteristics at this time, and it can be judged as an external interference signal.

[0024] In the above - mentioned technical solution, the bottom end of the metal guide rod 2.4 is a smooth and angular - free head. Being angular - free is to prevent discharge phenomena at the bottom end of the guide rod and prevent interference with the simulated partial - discharge insulation defects.

[0025] In the above - mentioned technical solution, the reference pot - type insulator 2.3 is a defect - free pot - type insulator.

[0026] An insulation - defect characteristic signal acquisition method based on the above - mentioned system, as Figure 2 shown, includes the following steps:

[0027] Step 1: Start the vibration platform 3 to make the gas - insulated switchgear partial - discharge defect model 2 simulate the vibration state during the operation of the gas - insulated switchgear;

[0028] Step 2: Use the non - partial - discharge voltage - applying module 1 to apply a voltage U to the metal guide rod 2.4 of the gas - insulated switchgear partial - discharge defect model 2. Determine the initial discharge voltage U of the test pot - type insulator 2.2 by using the pulse - current method according to the first pulse current signal output from the pulse - current signal output end of the non - partial - discharge voltage - applying module 1 or the second pulse current signal output from the test pot - type insulator 2.2 PDIV and then reduce the applied voltage U to the voltage U1, ensuring that the voltage U1 is lower than the initial discharge voltage U PDIV If the test pot - type insulator 2.2 cannot generate intermittent partial - discharge characteristics under the condition of the applied voltage U1, further increase or decrease the voltage U applied to the gas - insulated switchgear partial - discharge defect model 2 until the test pot - type insulator 2.2 can generate stable intermittent partial - discharge characteristics, and ensure that the voltage U1 is lower than the initial discharge voltage U during the adjustment PDIV ;

[0029] If the partial discharge defect model 2 of the gas-insulated switchgear can generate intermittent partial discharge characteristics under the applied voltage U1, the ultrasonic signal and the UHF signal of the partial discharge defect model 2 of the gas-insulated switchgear are respectively collected by the ultrasonic sensor 2.6 and the UHF sensor 2.7. The host 4 displays and stores the ultrasonic signal and the UHF signal, and uses the ultrasonic signal and the UHF signal to detect the discharge characteristics of the sparse partial discharge insulation defect.

[0030] In step 2 of the above technical features, the pulse current signal with high discharge pulse current sensing sensitivity in the non-partial discharge pressurizing module 1 and the test pothead insulator 2.2 is used to determine the initial discharge voltage U of the test pothead insulator 2.2 by the pulse current method. PDIV .

[0031] In step 2 of the above technical features, the third pulse current signal output by the reference pothead insulator 2.3 is used to judge whether there is an interference signal. If there is no interference, the waveforms of the second pulse current signal and the third pulse current signal are the same. If there is interference, they are different.

[0032] An insulation defect simulation method for the evolution of intermittent partial discharge into breakdown discharge based on the above system, as Figure 3 shown, first, a typical partial discharge insulation defect is simulated in the corresponding interval of the test pothead insulator 2.2 of the partial discharge defect model 2 of the gas-insulated switchgear, and then the simulation parameters of the typical partial discharge insulation defect are adjusted to obtain the initial discharge voltage U corresponding to the typical partial discharge insulation defect under different simulation parameters of the typical partial discharge insulation defect PDIV and the breakdown voltage U BD . The simulation parameters of the typical partial discharge insulation defect that make the initial discharge voltage U PDIV closest to the breakdown voltage U BD are selected as the experimental parameters. Finally, under this experimental parameter, a stable intermittent partial discharge simulation method of the gas-insulated switchgear is used to apply a voltage to the partial discharge insulation defect to realize the simulation of the insulation defect of the intermittent partial discharge evolving into a breakdown discharge. This method can effectively solve the technical problem that the numerical difference between the discharge voltage and the breakdown voltage of the intermittent partial discharge insulation defect is too large (if the difference is too large, a stable discharge characteristic will always be generated, and the natural simulation from intermittent discharge to breakdown discharge cannot be simulated), and the problem that the stable intermittent partial discharge simulation method cannot simulate the problem that the intermittent partial discharge insulation defect self-evolves into a breakdown discharge.

[0033] Typical partial discharge insulation defects include metal particle defects, metal protrusion defects, air gap defects, etc. The simulation parameters of typical partial discharge insulation defects include size, distance, and SF6 gas pressure. Among them, the size refers to the size of the typical partial discharge insulation defect itself, such as size and thickness; the distance refers to the distance between the high-voltage and low-voltage electrodes of the insulation defect itself; the gas pressure refers to the pressure of the SF6 gas filled in the interval.

[0034] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

Claims

1. A method for collecting insulation defect characteristic signals of an insulation defect detection system based on intermittent partial discharge, characterized in that: The system includes a non - partial - discharge voltage - boosting module (1), a partial - discharge defect model of gas - insulated switchgear (2), and a host computer (4). The partial - discharge defect model of gas - insulated switchgear (2) includes a discharge - defect simulation tank (2.1), a test pot - type insulator (2.2), a reference pot - type insulator (2.3), a metal guide rod (2.4), an inlet bushing (2.5), an ultrasonic sensor (2.6), and a UHF sensor (2.7). Among them, the centers of the test pot - type insulator (2.2) and the reference pot - type insulator (2.3) are fixedly penetrated on the metal guide rod (2.4). Both the test pot - type insulator (2.2) and the reference pot - type insulator (2.3) are located inside the discharge - defect simulation tank (2.1). The top end of the metal guide rod (2.4) passes through the top end of the discharge - defect simulation tank (2.1) and is fixedly connected to the inlet bushing (2.5). The ultrasonic sensor (2.6) is installed on the outer surface of the discharge - defect simulation tank (2.1), and the UHF sensor (2.7) is installed on the inner surface of the discharge - defect simulation tank (2.1). The voltage - signal output end of the non - partial - discharge voltage - boosting module (1) is connected to the metal guide rod (2.4) through the inlet bushing (2.5). The pulse - current - signal output end of the non - partial - discharge voltage - boosting module (1) is connected to the first pulse - current - signal input end of the host computer (4). The test pot - type insulator (2.2) is connected to the second pulse - current - signal input end of the host computer (4) through the detection impedance Z2. The reference pot - type insulator (2.3) is connected to the third pulse - current - signal input end of the host computer (4) through the detection impedance Z3. The ultrasonic - signal output end of the ultrasonic sensor (2.6) is connected to the ultrasonic - signal input end of the host computer (4). The UHF - signal output end of the UHF sensor (2.7) is connected to the UHF - signal input end of the host computer (4). The AC - phase - signal output end of the non - partial - discharge voltage - boosting module (1) is connected to the AC - phase - signal input end of the host computer (4). An insulation - defect characteristic - signal acquisition method includes the following steps: Step 1: Start the vibration platform (3) to make the partial - discharge defect model of gas - insulated switchgear (2) simulate the vibration state during the operation of the gas - insulated switchgear. Step 2: Apply a voltage U to the metal rod (2.4) of the gas-insulated switchgear partial discharge defect model (2) using the partial discharge-free voltage application module (1). Determine the inception discharge voltage U of the test pothead insulator (2.2) using the pulse current method based on the first pulse current signal output from the pulse current signal output terminal of the partial discharge-free voltage application module (1) or the second pulse current signal output from the test pothead insulator (2.2). PDIV Then, reduce the applied voltage U to a voltage U1, ensuring that the voltage U1 is lower than the inception discharge voltage U. PDIV If the test pothead insulator (2.2) cannot exhibit intermittent partial discharge characteristics under the applied voltage U1, further increase or decrease the voltage U applied to the gas-insulated switchgear partial discharge defect model (2) until the test pothead insulator (2.2) can exhibit stable intermittent partial discharge characteristics, while ensuring that the voltage U1 is lower than the inception discharge voltage U during the adjustment. PDIV ; If the partial - discharge defect model of gas - insulated switchgear (2) can generate intermittent partial - discharge characteristics under the applied voltage U1, the ultrasonic signal and UHF signal of the partial - discharge defect model of gas - insulated switchgear (2) are respectively collected by the ultrasonic sensor (2.6) and the UHF sensor (2.7).

2. The method for collecting insulation defect characteristic signals according to claim 1, characterized in that: It also includes a vibration platform (3) which is used to apply a vibration signal to the partial - discharge defect model of gas - insulated switchgear (2), simulate the vibration influence on the gas - insulated switchgear during the opening or closing of the circuit - breaker switch in the gas - insulated switchgear, and simulate the actual vibration situation generated during the operation of the gas - insulated switchgear.

3. The insulation defect characteristic signal acquisition method according to claim 2, wherein: The vibration platform (3) includes a programmable motor (3.1), a transmission shaft (3.2), and a vibration plate (3.3). The output shaft of the programmable motor (3.1) is connected to the vibration plate (3.3) through the transmission shaft (3.2). The programmable motor (3.1) is used to drive the vibration plate (3.3) to vibrate through the transmission shaft (3.2). The discharge defect simulation tank (2.1) is placed on the vibration plate (3.3).

4. The insulation defect characteristic signal acquisition method according to claim 1, wherein: The partial discharge-free pressurization module (1) includes a voltage regulator table T1, a step-up transformer T2, a current-limiting resistor Rr, capacitors C1 to C3, and a detection impedance Z1. The input end of the voltage regulator table T1 is connected to the current and voltage AC. One end of the primary of the step-up transformer T2 is connected to the voltage regulating resistor of the voltage regulator table T1, and the other end of the primary of the step-up transformer T2 is connected to the voltage regulating tap of the voltage regulator table T1. One end of the secondary of the step-up transformer T2 is connected to one end of the current-limiting resistor Rr. The other end of the current-limiting resistor Rr is the voltage signal output end of the partial discharge-free pressurization module (1). One end of the capacitor C3 is connected to the other end of the current-limiting resistor Rr, and the other end of the capacitor C3 is connected to one end of the detection impedance Z1. The other end of the secondary of the step-up transformer T2 is connected to the other end of the detection impedance Z1, and the other end of the secondary of the step-up transformer T2 is grounded; One end of the capacitor C1 is connected to the other end of the current-limiting resistor Rr, the other end of the capacitor C1 is connected to one end of the capacitor C2, and the other end of the capacitor C2 is connected to the other end of the detection impedance Z1. The other end of the capacitor C1 is the AC phase signal output end of the partial discharge-free pressurization module (1); One end of the detection impedance Z1 is the pulse current signal output end of the partial discharge-free pressurization module (1).

5. The insulation defect characteristic signal acquisition method according to claim 4, wherein: The partial discharge-free pressurization module (1) further includes a voltmeter V. One end of the voltmeter V is connected to one end of the capacitor C2, and the other end of the voltmeter V is connected to the other end of the secondary of the step-up transformer T2.

6. The method for collecting insulation defect characteristic signals according to claim 1 or 4, characterized in that: Both the test pot-type insulator (2.2) and the reference pot-type insulator (2.3) are grounded, and the test pot-type insulator (2.2) and the reference pot-type insulator (2.3) can be in different experimental intervals.

7. The method for collecting insulation defect characteristic signals according to claim 1, wherein: The bottom end of the metal guide rod (2.4) is a smooth and angular-free head.

8. The insulation defect characteristic signal acquisition method according to claim 1, characterized in that: The reference pot-type insulator (2.3) is a defect-free pot-type insulator.

9. An insulation defect simulation method for the evolution of intermittent partial discharge into breakdown discharge in an intermittent partial discharge insulation defect detection system, characterized in that: The system includes a partial discharge-free pressurization module (1), a gas-insulated switchgear partial discharge defect model (2), and a host (4); The partial discharge defect model (2) of the gas-insulated switchgear includes a discharge defect simulation tank (2.1), a test pothead insulator (2.2), a reference pothead insulator (2.3), a metal guide rod (2.4), an inlet bushing (2.5), an ultrasonic sensor (2.6), and a UHF sensor (2.7). Among them, the centers of the test pothead insulator (2.2) and the reference pothead insulator (2.3) are fixedly penetrated on the metal guide rod (2.4). The test pothead insulator (2.2) and the reference pothead insulator (2.3) are both located inside the discharge defect simulation tank (2.1). The top end of the metal guide rod (2.4) passes through the top end of the discharge defect simulation tank (2.1) and is fixedly connected to the inlet bushing (2.5). The ultrasonic sensor (2.6) is installed on the outer surface of the discharge defect simulation tank (2.1), and the UHF sensor (2.7) is installed on the inner surface of the discharge defect simulation tank (2.1); The voltage signal output terminal of the non-partial discharge pressurizing module (1) is connected to the metal guide rod (2.4) through the inlet bushing (2.5). The pulse current signal output terminal of the non-partial discharge pressurizing module (1) is connected to the first input terminal of the pulse current signal of the host (4). The test pothead insulator (2.2) is connected to the second input terminal of the pulse current signal of the host (4) through the detection impedance Z2. The reference pothead insulator (2.3) is connected to the third input terminal of the pulse current signal of the host (4) through the detection impedance Z3. The ultrasonic signal output terminal of the ultrasonic sensor (2.6) is connected to the ultrasonic signal input terminal of the host (4). The UHF signal output terminal of the UHF sensor (2.7) is connected to the UHF signal input terminal of the host (4). The AC phase signal output terminal of the non-partial discharge pressurizing module (1) is connected to the AC phase signal input terminal of the host (4); The insulation defect simulation method is to first simulate typical partial discharge insulation defects in the corresponding interval of the test pot insulator (2.2) of the partial discharge defect model (2) of the gas-insulated switchgear, and then adjust the simulation parameters of the typical partial discharge insulation defects to obtain the inception discharge voltage U corresponding to the typical partial discharge insulation defects under different simulation parameters of the typical partial discharge insulation defects. PDIV and the breakdown voltage U BD . Select the simulation parameters of the typical partial discharge insulation defect that makes the inception discharge voltage U PDIV closest to the breakdown voltage U BD as the experimental parameters. Finally, apply a voltage to the partial discharge insulation defect by using the stable intermittent partial discharge simulation method of the gas-insulated switchgear under these experimental parameters to achieve the insulation defect simulation of the intermittent partial discharge evolving into a breakdown discharge.

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