Method and system for evaluating insulation state of voltage-sharing capacitor of extra-high voltage GIS circuit breaker

Abstract

The invention relates to an extra-high voltage GIS circuit breaker voltage-sharing capacitor insulation state evaluation method and system, and relates to the technical field of high voltage equipment detection. According to the method, two sides of the extra-high voltage GIS circuit breaker are respectively provided with a built-in ultrahigh frequency sensor, and the built-in ultrahigh frequency sensors on the two sides are utilized to determine a standard electromagnetic pulse excited due to the fact that a voltage-sharing capacitor on the right side has defects, and the standard electromagnetic pulse is named as a II-type high-frequency electromagnetic pulse; determining a standard electromagnetic pulse excited by the defect of the voltage-sharing capacitor on the left side, and naming the standard electromagnetic pulse as a III-type high-frequency electromagnetic pulse; and comparing the monitored high-frequency electromagnetic original pulse with the II-type high-frequency electromagnetic pulse and the III-type high-frequency electromagnetic pulse to determine whether the insulation state of the voltage-sharing capacitor is abnormal or not.

Description

Technical Field

[0001] The present application relates to the technical field of high-voltage equipment detection, and in particular to a method and system for evaluating the insulation status of a grading capacitor of an ultra-high voltage GIS circuit breaker. Background Art

[0002] Ultra-high voltage (UHV) GIS (Gas Insulated Switchgear) circuit breakers typically employ a multi-break structure. To ensure that each break experiences consistent voltage during opening and closing, grading capacitors are connected in parallel between the breakpoints. While the UHV GIS circuit breaker is closed, the grading capacitors are protected from voltage. However, during hot standby operation, they experience higher voltages. Defective grading capacitors can cause insulation breakdown during hot standby operation, leading to GIS breaker failure.

[0003] Because the GIS circuit breaker's grading capacitor is sealed inside the GIS tank, its external condition cannot be observed, and conventional testing methods cannot verify the capacitor's insulation performance parameters. During the circuit breaker closing phase, there is no voltage difference across the capacitor. Therefore, commonly used live testing methods such as ultra-high frequency and ultrasonic waves cannot verify the insulation condition of the grading capacitor.

[0004] Because the grading capacitors of a circuit breaker are subject to voltage in hot standby mode, and the strong shock vibrations caused by the circuit breaker's opening and closing operations can easily trigger defects in the grading capacitors, occasional high-frequency electromagnetic pulses (EMPs) may occur during operation and in the short period following. Pre-breakdown and restrike between the breakpoints during the breaker's opening and closing also trigger high-frequency electromagnetic pulses. These high-frequency electromagnetic pulses overlap, making it difficult to filter out pulses caused by grading capacitor defects. Summary of the Invention

[0005] The purpose of this application is to provide a method and system for evaluating the insulation status of a grading capacitor of an ultra-high voltage GIS circuit breaker, wherein the method and system are used for evaluating the insulation status of the grading capacitor.

[0006] In order to achieve the above objectives, in a first aspect, the present invention provides a method for evaluating the insulation status of a grading capacitor of an ultra-high voltage GIS circuit breaker, the method comprising the following steps: S1: A built-in UHF sensor is installed on each side of the UHV GIS circuit breaker; S2: During the closing process of the UHV GIS circuit breaker, the built-in UHF sensors on both sides are used to monitor the high-frequency electromagnetic original pulses inside the UHV GIS circuit breaker; S3: Using the built-in UHF sensors on both sides, the standard electromagnetic pulse generated by the defective grading capacitor on the right side is determined to be a Class II high-frequency electromagnetic pulse. The standard electromagnetic pulse generated by the defective grading capacitor on the left side is determined to be a Class III high-frequency electromagnetic pulse. S4: Compare the high-frequency electromagnetic original pulse monitored in S2 with the Class II and Class III high-frequency electromagnetic pulses to determine whether the insulation state of the grading capacitor is abnormal.

[0007] In an optional embodiment, S1 includes: The distance between the left grading capacitor and the built-in UHF sensor is a, and the distance between the right grading capacitor and the built-in UHF sensor is also a.

[0008] In an optional embodiment, S2 includes: The high-frequency electromagnetic pulse signal received by the built-in ultra-high frequency sensor is pre-processed, and the high-frequency components in the range of 300MHz to 1500MHz in the high-frequency electromagnetic pulse signal are filtered and amplified.

[0009] In an optional embodiment, S3 includes: The pulse time-frequency characteristics of Class II and Class III high-frequency electromagnetic pulses are determined respectively, and the pulse time-frequency characteristics are used as the standard for identifying them as Class II or Class III high-frequency electromagnetic pulses.

[0010] In an optional embodiment, the pulse time-frequency characteristics of the Class II high-frequency electromagnetic pulse include: the peak-to-peak value of the electromagnetic signal is 700mV~900mV, the high-frequency component lasts 500ns~600ns, and the wave head of the signal collected by the built-in ultra-high frequency sensor on the right side leads the time difference △T compared to the built-in ultra-high frequency sensor on the left side.

[0011] In an optional embodiment, ΔT satisfies the following relationship: (1) Where L is the distance between the two built-in UHF sensors, C is the propagation speed of electromagnetic radiation, and a is the distance between the signal source and the built-in UHF sensor on the right.

[0012] In an optional embodiment, the pulse time-frequency characteristics of the Class III high-frequency electromagnetic pulse include: the peak-to-peak value of the electromagnetic signal is 700mV~900mV, the high-frequency component lasts 500ns~600ns, and the wave head of the signal collected by the built-in ultra-high frequency sensor on the left is ahead of the time difference △T compared with the built-in ultra-high frequency sensor on the right.

[0013] In an optional embodiment, S4 includes: Count the number of occurrences N and duration T of Class II and Class III high-frequency electromagnetic pulses in the high-frequency electromagnetic original pulses monitored in S2; Based on the number N and the duration T, determine whether the insulation state of the grading capacitor is abnormal.

[0014] In an optional embodiment, determining whether the insulation state of the grading capacitor is abnormal based on the number N and the duration T includes: When N is less than 50 and T is less than 2 seconds, the insulation status of the grading capacitor is normal; when N is greater than or equal to 50 or T is greater than or equal to 2 seconds, the insulation status of the grading capacitor is in a warning state and the operation can be monitored; when N is greater than or equal to 1000 and T is greater than or equal to 5 seconds, the insulation status of the grading capacitor is abnormal and power outage for maintenance is required.

[0015] In a second aspect, the present invention provides a system for evaluating the insulation status of a grading capacitor of an ultra-high voltage GIS circuit breaker, the system comprising: Two built-in UHF sensors are installed on both sides of the UHV GIS circuit breaker to monitor the high-frequency electromagnetic original pulses inside the UHV GIS circuit breaker; The UHF amplification processing unit is used to pre-process the high-frequency electromagnetic pulse signal received by the built-in UHF sensor; The processor is used to compare the monitored high-frequency electromagnetic original pulse with Class II and Class III high-frequency electromagnetic pulses to determine whether the insulation state of the grading capacitor is abnormal; among them, the standard electromagnetic pulse excited by determining that the grading capacitor on the right side has a defect is named as Class II high-frequency electromagnetic pulse; the standard electromagnetic pulse excited by determining that the grading capacitor on the left side has a defect is named as Class III high-frequency electromagnetic pulse.

[0016] Through the above technical solution, during the operation of the UHV GIS circuit breaker, high-frequency electromagnetic original pulses are monitored and interference is eliminated using the pulse time-frequency characteristics. Abnormal high-frequency electromagnetic original pulses excited by the grading capacitor are screened out and used to evaluate the insulation status of the grading capacitor.

[0017] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A flowchart of a method for evaluating the insulation status of a grading capacitor of a UHV GIS circuit breaker based on high-frequency electromagnetic raw pulse monitoring provided in an embodiment of the present application; Figure 2This is a schematic diagram of the internal structure of the UHV GIS circuit breaker and the layout of the built-in UHF sensors on both sides; Figure 3 High-frequency electromagnetic signals generated by pre-breakdown and restrike of the break in the UHV GIS circuit breaker; Figure 4 This is the high-frequency electromagnetic signal excited by the grading capacitor on the right side of the UHV GIS circuit breaker; Figure 5 The time delay of the high-frequency electromagnetic signal excited by the grading capacitor on the right side of the UHV GIS circuit breaker; Figure 6 This is the high-frequency electromagnetic signal excited by the grading capacitor on the left side of the UHV GIS circuit breaker; Figure 7 is the time delay of the high-frequency electromagnetic signal excited by the grading capacitor on the left side of the UHV GIS circuit breaker.

[0020] Icon: 1-Built-in UHF sensor; 2-Equalizing capacitor. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0022] In the description of this application, it should be noted that the terms "inner" and "outer" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended solely to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0023] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0024] This application proposes a method for evaluating the insulation condition of the grading capacitor of an ultra-high voltage GIS circuit breaker based on high-frequency electromagnetic original pulse monitoring (hereinafter referred to as the method). During the operation of the ultra-high voltage GIS circuit breaker, high-frequency electromagnetic original pulses are monitored, and interference is eliminated by using the pulse time-frequency characteristics. Abnormal high-frequency electromagnetic original pulses excited by the grading capacitor are screened out and used for insulation condition evaluation of the grading capacitor.

[0025] For details, please refer to Figure 1 , the method comprises the following steps: S1: A built-in UHF sensor 1 is provided on each side of the UHV GIS circuit breaker.

[0026] The structure of the dual-port UHV GIS circuit breaker is as follows: Figure 2 As shown, a built-in UHF sensor 1 is provided on each side of the UHV GIS circuit breaker. Specifically, the distance between the grading capacitor 2 on the left and the built-in UHF sensor 1 (also known as: 1# sensor) on the left is a, and the distance between the grading capacitor 2 on the right and the built-in UHF sensor 1 (also known as: 2# sensor) on the right is also a. The two built-in UHF sensors 1 are L meters apart. Specifically, a can be 6.5 meters and L can be 17.2 meters.

[0027] S2: During the closing process of the UHV GIS circuit breaker, the built-in UHV sensors 1 on both sides are used to monitor the high-frequency electromagnetic original pulses inside the UHV GIS circuit breaker.

[0028] The UHF amplification processing unit pre-processes the high-frequency electromagnetic pulse signal received by the built-in UHF sensor 1, filtering and amplifying the high-frequency components in the 300MHz to 1500MHz range of the high-frequency electromagnetic pulse signal. The UHF amplification processing unit is connected to the high-frequency signal acquisition unit via a signal cable. This application requires that the sampling rate of the built-in UHF sensor 1 be no less than 2Gs / S and the analog bandwidth be no less than 800MHz.

[0029] S3: Using the built-in UHF sensors 1 on both sides, it is determined that the voltage-equalizing capacitor 2 on the right side has a defect and the resulting standard electromagnetic pulse is named a Class II high-frequency electromagnetic pulse; it is determined that the voltage-equalizing capacitor 2 on the left side has a defect and the resulting standard electromagnetic pulse is named a Class III high-frequency electromagnetic pulse.

[0030] The pulse time-frequency characteristics of Class I, Class II and Class III high-frequency electromagnetic pulses are determined respectively, and the pulse time-frequency characteristics are used as the standard for identifying them as Class I, Class II or Class III high-frequency electromagnetic pulses.

[0031] During the closing process of the UHV GIS circuit breaker, pre-breakdown may occur between the fractures, which will also generate high-frequency electromagnetic pulses, which are named as Class I high-frequency electromagnetic pulses in this application. The signals measured by the 1# sensor and the 2# sensor are as follows: Figure 3 shown.

[0032] The time-frequency characteristics of a Class I high-frequency electromagnetic pulse include: the peak-to-peak value of the electromagnetic signal measured by sensor #1 is 900mV to 1100mV, specifically 1000mV, the high-frequency component lasts 700ns to 900ns, specifically 800ns, and the wave tail has significant low-frequency oscillations. The peak-to-peak value of the electromagnetic signal measured by sensor #2 is 2800mV to 3200mV, specifically 3000mV, the high-frequency component lasts 900ns to 1100ns, specifically 1000ns, and the wave tail also has significant low-frequency oscillations. Due to the limited number of pre-breakdowns in UHV GIS circuit breakers, the occurrence of Class I high-frequency electromagnetic pulses is typically less than 10.

[0033] During the closing process of the UHV GIS circuit breaker, if there is a latent defect in the grading capacitor 2, a high-frequency electromagnetic signal will be excited by the strong impact vibration of the operating mechanism. If there is a defect in the grading capacitor 2 on the right, the standard electromagnetic pulse excited is as follows: Figure 4 As shown, it is named as Class II high frequency electromagnetic pulse in this application.

[0034] It can be seen that the pulse time-frequency characteristics of Class II high-frequency electromagnetic pulses include: the peak-to-peak value of the electromagnetic signal measured by sensor 1# is 700mV~900mV, specifically 800mV, the high-frequency component lasts 500ns~600ns, specifically 550ns, and there is no low-frequency oscillation at the tail of the wave. The peak-to-peak value of the electromagnetic signal measured by sensor 2# is also 700mV~900mV, specifically 800mV, the high-frequency component lasts 500ns~600ns, specifically 550ns, and there is no low-frequency oscillation at the tail of the wave. The signals received by sensor 1# and sensor 2# are similar, and their wave heads are expanded as shown below. Figure 5 As shown in the figure, it can be seen that the time difference △T of sensor 2# is about 14ns ahead of sensor 1#. Using formula (1): (1) Among them, L is the distance between sensor 1# and sensor 2#, which is 17.2 meters. △T is the time difference between sensor 2# and sensor 1#, which is about 14ns. C is the propagation speed of electromagnetic radiation, which is 0.3m / ns. It can be inferred that the distance between the signal source and sensor 2# is 6.5m. It can be basically determined that the signal comes from the equalizing capacitor 2 on the right.

[0035] During the closing process of the UHV GIS circuit breaker, if there is a defect in the voltage-grading capacitor 2 on the left, the standard electromagnetic pulse excited is as follows: Figure 6 As shown, it is named as Class III high frequency electromagnetic pulse in this application.

[0036] It can be seen that the pulse time-frequency characteristics of the Class III high-frequency electromagnetic pulse include: the signals received by sensor 1# and sensor 2# are also similar, the peak-to-peak value of the measured electromagnetic signal is 700mV~900mV, specifically 800mV, the high-frequency component lasts 500ns~600ns, specifically 550ns, and there is no low-frequency oscillation at the tail of the wave. Figure 7 As shown in the figure, the time difference ΔT between sensor 1# and sensor 2# is approximately 14 ns. Using formula (1), L is the distance between sensor 1# and sensor 2#, which is 17.2 meters, ΔT is the time difference between sensor 1# and sensor 2#, which is approximately 14 ns, and C is the electromagnetic propagation speed, which is 0.3 m / ns. It can be inferred that the distance between the signal source and sensor 1# is 6.5 meters, which basically confirms that the signal comes from the voltage-equalizing capacitor 2 on the left.

[0037] S4: Compare the high-frequency electromagnetic original pulse monitored in S2 with the Class II and Class III high-frequency electromagnetic pulses to determine whether the insulation state of the grading capacitor 2 is abnormal.

[0038] If Class II and Class III high-frequency electromagnetic pulses (HFEMPs) occur during the closing process of a UHV GIS circuit breaker, this indicates a potential insulation anomaly in grading capacitor 2, potentially indicating a potential defect. Since grading capacitor 2 is no longer subject to voltage after the UHV GIS circuit breaker is closed, even a defect in grading capacitor 2 will no longer generate Class II and Class III HFEMPs. Therefore, it is necessary to reconfirm this by monitoring the original HFEM pulses during the opening process of the UHV GIS circuit breaker.

[0039] During the opening process of a UHV GIS circuit breaker, if there is a defect in grading capacitor 2, the impact vibration of the mechanism will induce an electromagnetic pulse inside the UHV GIS circuit breaker, similar to the closing process. A defect in grading capacitor 2 on the right side corresponds to a Class II high-frequency electromagnetic pulse, while a defect on the left side corresponds to a Class III high-frequency electromagnetic pulse.

[0040] Therefore, firstly, the number N and duration T of the Class II and Class III high-frequency electromagnetic pulses in the high-frequency electromagnetic original pulses monitored in S2 are counted; then, based on the number N and duration T, it is determined whether the insulation state of the grading capacitor 2 is abnormal.

[0041] This application proposes that when N is less than 50 and T is less than 2 seconds, the insulation state of the equalizing capacitor 2 is normal; when N is greater than or equal to 50 or T is greater than or equal to 2 seconds, the insulation state of the equalizing capacitor 2 is a warning state and the operation can be monitored; when N is greater than or equal to 1000 and T is greater than or equal to 5 seconds, the insulation state of the equalizing capacitor 2 is abnormal and requires power outage for maintenance.

[0042] In this way, a method for evaluating the dynamic insulation state of the grading voltage is proposed by comprehensively analyzing the number and duration of Class II and Class III high-frequency electromagnetic pulses excited inside the UHV GIS circuit breaker during the opening and closing process of the UHV GIS circuit breaker.

[0043] Based on the same concept, this embodiment also proposes a UHV GIS circuit breaker grading capacitor insulation condition assessment system (hereinafter referred to as the system), which includes: Two built-in UHF sensors 1 are installed on both sides of the UHV GIS circuit breaker to monitor the high-frequency electromagnetic original pulses inside the UHV GIS circuit breaker; The UHF amplification processing unit is connected to the two built-in UHF sensors 1 and is used to pre-process the high-frequency electromagnetic pulse signals received by the built-in UHF sensors 1; The processor is connected to the ultra-high frequency amplification processing unit and is used to compare the monitored high-frequency electromagnetic original pulse with the Class II and Class III high-frequency electromagnetic pulses to determine whether the insulation state of the grading capacitor 2 is abnormal; among them, the standard electromagnetic pulse excited by determining that the grading capacitor 2 on the right side has a defect is named as the Class II high-frequency electromagnetic pulse; the standard electromagnetic pulse excited by determining that the grading capacitor 2 on the left side has a defect is named as the Class III high-frequency electromagnetic pulse.

[0044] The method and system for evaluating the insulation status of the grading capacitor of a UHV GIS circuit breaker provided in this embodiment have the following beneficial effects: By utilizing the pulse time-frequency characteristics of the high-frequency electromagnetic pulse excited by the grading capacitor 2 in the defective state, it is possible to accurately identify whether the grading capacitor 2 has defects, thereby avoiding misjudgment caused by the high-frequency electromagnetic pulse generated by the pre-breakdown between the fractures and improving the accuracy of defect identification of the grading capacitor 2.

[0045] It should be noted that, unless there is any conflict, the features in the embodiments of this application can be combined with each other.

[0046] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for evaluating the insulation status of a grading capacitor of a UHV GIS circuit breaker, characterized in that: The method comprises the following steps: S1: A built-in UHF sensor (1) is provided on each side of the UHV GIS circuit breaker; S2: During the closing process of the UHV GIS circuit breaker, the built-in UHV sensors (1) on both sides are used to monitor the high-frequency electromagnetic original pulses inside the UHV GIS circuit breaker; S3: Using the built-in UHF sensors (1) on both sides, a standard electromagnetic pulse is generated when the voltage-equalizing capacitor (2) on the right side is determined to be defective, which is named as a Class II high-frequency electromagnetic pulse; a standard electromagnetic pulse is generated when the voltage-equalizing capacitor (2) on the left side is determined to be defective, which is named as a Class III high-frequency electromagnetic pulse; S4: Compare the high-frequency electromagnetic original pulse monitored in S2 with the Class II and Class III high-frequency electromagnetic pulses to determine whether the insulation state of the grading capacitor (2) is abnormal.

2. The method for evaluating the insulation status of the grading capacitor of a UHV GIS circuit breaker according to claim 1, characterized in that: S1 includes: The distance between the left-side voltage-equalizing capacitor (2) and the left-side built-in ultra-high frequency sensor (1) is a, and the distance between the right-side voltage-equalizing capacitor (2) and the right-side built-in ultra-high frequency sensor (1) is also a.

3. The method for evaluating the insulation status of a grading capacitor of a UHV GIS circuit breaker according to claim 1, wherein S2 include: The high-frequency electromagnetic pulse signal received by the built-in ultra-high frequency sensor (1) is pre-processed, and the high-frequency components within the range of 300MHz to 1500MHz in the high-frequency electromagnetic pulse signal are filtered and amplified.

4. The method for evaluating the insulation status of a grading capacitor of a UHV GIS circuit breaker according to claim 1, wherein S3 include: The pulse time-frequency characteristics of Class II and Class III high-frequency electromagnetic pulses are determined respectively, and the pulse time-frequency characteristics are used as the standard for identifying Class II or Class III high-frequency electromagnetic pulses.

5. The method for evaluating the insulation status of the grading capacitor of a UHV GIS circuit breaker according to claim 4, characterized in that: The pulse time-frequency characteristics of the Class II high-frequency electromagnetic pulse include: the peak-to-peak value of the electromagnetic signal is 700mV~900mV, the high-frequency component lasts for 500ns~600ns, and the wave head of the signal collected by the built-in ultra-high frequency sensor (1) on the right side leads the time difference △T compared with the built-in ultra-high frequency sensor (1) on the left side.

6. The method for evaluating the insulation status of the grading capacitor of a UHV GIS circuit breaker according to claim 5, characterized in that: △T satisfies the following relationship: (1) Wherein, L is the distance between the two built-in UHF sensors (1), C is the propagation speed of electromagnetic, and a is the distance between the signal source and the built-in UHF sensor (1) on the right.

7. The method for evaluating the insulation status of the grading capacitor of a UHV GIS circuit breaker according to claim 4, characterized in that: The pulse time-frequency characteristics of the Class III high-frequency electromagnetic pulse include: the peak-to-peak value of the electromagnetic signal is 700mV~900mV, the high-frequency component lasts for 500ns~600ns, and the wave head of the signal collected by the left built-in ultra-high frequency sensor (1) leads the time difference △T compared with the right built-in ultra-high frequency sensor (1).

8. The method for evaluating the insulation status of a grading capacitor of a UHV GIS circuit breaker according to claim 1, wherein S4 include: Count the number of occurrences N and duration T of Class II and Class III high-frequency electromagnetic pulses in the high-frequency electromagnetic original pulses monitored in S2; Based on the number N and the duration T, determine whether the insulation state of the voltage grading capacitor (2) is abnormal.

9. The method for evaluating the insulation status of the grading capacitor of a UHV GIS circuit breaker according to claim 8, characterized in that: The method of determining whether the insulation state of the voltage grading capacitor (2) is abnormal based on the number of times N and the duration T includes: When N < 50 and T < 2 seconds, the insulation state of the grading capacitor (2) is normal; when N ≥ 50 or T ≥ 2 seconds, the insulation state of the grading capacitor (2) is cautionary and can be monitored; when N ≥ 1000 and T ≥ 5 seconds, the insulation state of the grading capacitor (2) is abnormal and requires power outage for maintenance.

10. A UHV GIS circuit breaker grading capacitor insulation status assessment system, characterized in that: The system comprises: Two built-in ultra-high frequency sensors (1) are installed on both sides of the ultra-high voltage GIS circuit breaker and are used to monitor the high-frequency electromagnetic original pulses inside the ultra-high voltage GIS circuit breaker; A UHF amplification processing unit, used for pre-processing the high-frequency electromagnetic pulse signal received by the built-in UHF sensor (1); The processor is used to compare the monitored high-frequency electromagnetic original pulse with the Class II and Class III high-frequency electromagnetic pulses to determine whether the insulation state of the voltage-equalizing capacitor (2) is abnormal; wherein, the standard electromagnetic pulse excited by determining that the voltage-equalizing capacitor (2) on the right side has a defect is named the Class II high-frequency electromagnetic pulse; the standard electromagnetic pulse excited by determining that the voltage-equalizing capacitor (2) on the left side has a defect is named the Class III high-frequency electromagnetic pulse.

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