A method and system for identifying partial discharge of an extra-high voltage GIS disconnector gas chamber

Abstract

The application discloses a kind of partial discharge identification method and system of extra-high voltage GIS disconnecting switch gas chamber, comprising: three outside extra-high frequency sensors are arranged in the gas chamber of extra-high voltage GIS disconnecting switch, wherein, first sensor is placed on the upper end of the lower part of the gas chamber basin type insulator, second sensor is placed on the lower end of the upper part of the gas chamber basin type insulator, third sensor is placed on the lower end of the lower part of the gas chamber basin type insulator;When the partial discharge time difference received by sensor and second sensor is within the first preset threshold range, and the partial discharge time difference received by first sensor and sensor is greater than the second preset threshold, and the partial discharge signal in the gas chamber of the extra-high voltage GIS disconnecting switch meets the discharge characteristics of solid insulation, it is determined that there is partial discharge between the switching resistance insulation support rod or the outer sheath and the grading ring of the gas chamber of extra-high voltage GIS disconnecting switch.The demand problem of the current partial discharge judgment method of extra-high voltage GIS disconnecting switch gas chamber is solved.

Description

Technical Field

[0001] This invention relates to the field of power transmission and transformation equipment status sensing, specifically to a method and system for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector. Background Technology

[0002] Gas-insulated switchgear (GIS) is a critical piece of equipment in power systems, primarily used to isolate power system faults and alter system operation modes. With the increasing scale of my country's power grid, GIS insulation discharge faults are becoming more frequent. Therefore, in the field, ultra-high frequency (UHF) sensors built into the GIS are typically used to detect partial discharges, thereby determining whether there are potential insulation discharge faults and preventing GIS failures.

[0003] When UHV GIS disconnecting switches open and close busbars, multiple reignitions can occur between the contacts due to the slow movement speed and poor arc-extinguishing performance of the disconnecting switch contacts. This transient process generates a step voltage traveling wave distortion, leading to VFTO (Voltage-Free Transient). Currently, in ultra-high voltage and UHV systems, it is common practice to connect opening and closing resistors in parallel at the disconnecting switch break to limit the amplitude and steepness of VFTO. However, the operating mechanism of the opening and closing resistors is complex and poses numerous partial discharge risks. Quickly and accurately determining the location of partial discharge within the gas chamber of the GIS disconnecting switch will greatly improve the operation and maintenance level of UHV GIS. However, a method for judging partial discharge in the equalizing ring of the closing resistor diaphragm in the gas chamber of UHV GIS disconnecting switches is currently lacking. Summary of the Invention

[0004] To address the above problems, this invention provides a method for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector, comprising:

[0005] Three external UHF sensors are arranged in the air chamber of the UHV GIS disconnector. The first external UHF sensor is placed on the upper end of the lower basin insulator of the air chamber, the second external UHF sensor is placed on the lower end of the upper basin insulator of the air chamber, and the third external UHF sensor is placed on the lower end of the lower basin insulator of the air chamber.

[0006] When the time difference between partial discharge received by the first external UHF sensor and the second external UHF sensor is within the first preset threshold range, and the time difference between partial discharge received by the first external UHF sensor and the third external UHF sensor is greater than the second preset threshold, and the partial discharge signal in the gas chamber of the UHV GIS disconnector matches the characteristics of solid insulation discharge, then it is determined that there is partial discharge between the switching resistor insulation support rod or outer sheath and the equalizing ring in the gas chamber of the UHV GIS disconnector.

[0007] Furthermore, the first preset threshold range is specifically 1ns to 6ns.

[0008] Furthermore, the second preset threshold is 1 ns.

[0009] Furthermore, the partial discharge signal in the gas chamber of the UHV GIS disconnector conforms to the characteristics of solid-insulation discharge, including:

[0010] The partial discharge signal in the gas chamber of the ultra-high voltage GIS disconnector has a stable discharge phase, exhibits polarity effects, and has a dispersed amplitude.

[0011] This invention also provides a system for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector, comprising:

[0012] The sensor module is used to arrange three external ultra-high frequency sensors in the gas chamber of the ultra-high voltage GIS disconnector. The first external ultra-high frequency sensor is placed on the upper end of the lower basin insulator of the gas chamber, the second external ultra-high frequency sensor is placed on the lower end of the upper basin insulator of the gas chamber, and the third external ultra-high frequency sensor is placed on the lower end of the lower basin insulator of the gas chamber.

[0013] The identification module is used to determine that there is a partial discharge between the switching resistor insulation support rod or outer sheath and the equalizing ring in the gas chamber of the UHV GIS disconnector when the time difference between the partial discharge received by the first external UHV sensor and the second external UHV sensor is within a first preset threshold range, and the time difference between the partial discharge received by the first external UHV sensor and the third external UHV sensor is greater than a second preset threshold, and the partial discharge signal in the gas chamber of the UHV GIS disconnector matches the characteristics of solid insulation discharge.

[0014] This application provides a method and system for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector switch. It addresses the lack of an effective on-site verification method for the sensitivity of built-in UHF sensors during the commissioning test of newly installed GIS, ensuring the effectiveness of the built-in UHF sensors in newly installed GIS and avoiding missed or false alarms due to insufficient sensor sensitivity. It also addresses the lack of an effective on-site verification method for the sensitivity of built-in UHF sensors after GIS has been in operation for a period of time, allowing for timely assessment of the effectiveness of built-in UHF sensors in operating GIS and avoiding missed or false alarms due to sensor failure. In summary, the method and system provided in this application address the current need for a method to determine partial discharge in the closing resistor equipotential ring of an ultra-high voltage GIS disconnector switch. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating a method for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector provided in an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram showing the arrangement of the external ultra-high frequency sensor according to an embodiment of the present invention;

[0017] Figure 3 This is a typical original signal diagram of the external ultra-high frequency sensor in an embodiment of the present invention;

[0018] Figure 4 This is a typical PRPD-PRPS signal diagram of the external ultra-high frequency sensor in an embodiment of the present invention;

[0019] Figure 5 This is a comprehensive monitoring diagram of the phase switch gas chamber of embodiment T0612C of the present invention; 3

[0020] Figure 6 This is a schematic diagram of the structure of a partial discharge identification system for an ultra-high voltage GIS disconnector switch chamber provided in an embodiment of the present invention. Detailed Implementation

[0021] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Figure 1 This is a flowchart illustrating a method for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector provided in an embodiment of the present invention. The following is a detailed explanation in conjunction with... Figure 1 The method provided in the embodiments of the present invention will be described in detail.

[0023] Step S101: Three external UHF sensors are arranged in the gas chamber of the UHV GIS disconnector. The first external UHF sensor is placed on the upper end of the lower basin-type insulator of the gas chamber, the second external UHF sensor is placed on the lower end of the upper basin-type insulator of the gas chamber, and the third external UHF sensor is placed on the lower end of the lower basin-type insulator of the gas chamber.

[0024] To determine the partial discharge status of the equalizing ring of the closing resistor pad in the UHV GIS disconnector switch chamber, this invention first specifies the arrangement of external UHV high-frequency sensors. Three external sensors are used to monitor the partial discharge in the UHV GIS disconnector switch chamber. Sensor A is placed at the upper end of the lower basin-type insulator, sensor B is placed at the lower end of the upper basin-type insulator, and sensor C is placed at the lower end of the lower basin-type insulator. The specific arrangement is detailed in the appendix. Figure 2 .

[0025] Step S102: When the time difference of partial discharge received by the first external UHF sensor and the second external UHF sensor is within the first preset threshold range, and the time difference of partial discharge received by the first external UHF sensor and the third external UHF sensor is greater than the second preset threshold, and the partial discharge signal in the gas chamber of the UHV GIS disconnector meets the characteristics of solid insulation discharge, then it is determined that there is a partial discharge between the switching resistor insulation support rod or outer sheath and the equalizing ring in the gas chamber of the UHV GIS disconnector.

[0026] The first preset threshold range is specifically 1ns to 6ns. The second preset threshold is 1ns.

[0027] This invention proposes a criterion for determining whether there is partial discharge between the insulating support rod or outer sheath of the gas chamber switching resistor of an ultra-high voltage GIS disconnector and the equalizing ring.

[0028] (1) The partial discharge signal time difference characteristics meet the requirements. The partial discharge signal time difference of external sensor A exceeds that of external sensor B by 1ns to 6ns, and the partial discharge signal time difference of external sensor A exceeds that of external sensor C by more than 1ns. The time domain characteristic diagram is shown in the appendix. Figure 3 .

[0029] (2) The spectral characteristics of the partial discharge signal meet the requirements. The ultra-high frequency partial discharge signal in the isolating switch chamber exhibits solid-insulation discharge characteristics, with a relatively stable discharge phase, obvious polarity effect, and a certain degree of amplitude dispersion. One possible typical spectrum is shown in the appendix. Figure 4 .

[0030] When the UHF partial discharge signal meets the above two requirements, it can be considered that there is a UHF signal between the switching resistor insulation support rod or outer sheath and the equalizing ring, that is, there is partial discharge between the switching resistor insulation support rod or outer sheath and the equalizing ring in the UHF GIS disconnector gas chamber.

[0031] This invention introduces a method for arranging external sensors for ultra-high frequency (UHV) circuits and a method for determining partial discharge. It has advantages such as strong on-site operability, accurate judgment, sensitive response, and ease of implementation, and can be widely applied to the partial discharge determination of the equalizing ring of the closing resistor pad in the UHV GIS disconnector switch. Specific application examples are as follows:

[0032] Since 2021, the OCU-19C sensor for partial discharge monitoring at the 1000kV GIS at the Anji UHV substation has frequently issued partial discharge alarms, with the signal type being insulation-related partial discharge. The expert team analyzed the test results and preliminarily confirmed the presence of insulation-related partial discharge in the C-phase gas chamber of switch T0612. They also found that the signal has exhibited strong intermittent characteristics since April, with the daily maximum number of partial discharge events varying (increasing or decreasing) by more than 30%, necessitating 12-hour comprehensive monitoring.

[0033] The flexible circuit breaker expert team conducted comprehensive monitoring of the T0612C phase switch and found no abnormal ultrasonic signals. During 12 hours of comprehensive monitoring, a total of 114 partial discharge signals within the GIS were detected. Based on these signals, time difference positioning statistics were performed, revealing that sensor A leads sensor B by an expected value of 1.37 ns (0.411 m), and sensor A leads sensor C by an expected value of 1.08 ns (0.324 m). This is consistent with the time difference characteristics of ultra-high frequency signals of partial discharge between the switching resistor insulation sheath and the diaphragm equalizing ring (see attached). Figure 5 ).

[0034] Based on the same inventive concept, this invention provides a partial discharge identification system 600 for the gas chamber of an ultra-high voltage GIS disconnector, such as... Figure 6 As shown, it includes:

[0035] Sensor module 6100 is used to arrange three external ultra-high frequency sensors in the gas chamber of the ultra-high voltage GIS disconnector. The first external ultra-high frequency sensor is placed on the upper end of the lower basin insulator of the gas chamber, the second external ultra-high frequency sensor is placed on the lower end of the upper basin insulator of the gas chamber, and the third external ultra-high frequency sensor is placed on the lower end of the lower basin insulator of the gas chamber.

[0036] The identification module 620 is used to determine that there is a partial discharge between the switching resistor insulation support rod or outer sheath and the equalizing ring in the gas chamber of the UHV GIS disconnector when the time difference of partial discharge received by the first external UHV sensor and the second external UHV sensor is within a first preset threshold range, and the time difference of partial discharge received by the first external UHV sensor and the third external UHV sensor is greater than a second preset threshold, and the partial discharge signal in the gas chamber of the UHV GIS disconnector matches the characteristics of solid insulation discharge.

[0037] This application provides a method and system for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector switch. It addresses the lack of an effective on-site verification method for the sensitivity of built-in UHF sensors during the commissioning test of newly installed GIS, ensuring the effectiveness of the built-in UHF sensors in newly installed GIS and avoiding missed or false alarms due to insufficient sensor sensitivity. It also addresses the lack of an effective on-site verification method for the sensitivity of built-in UHF sensors after GIS has been in operation for a period of time, allowing for timely assessment of the effectiveness of built-in UHF sensors in operating GIS and avoiding missed or false alarms due to sensor failure. In summary, the method and system provided in this application address the current need for a method to determine partial discharge in the closing resistor equipotential ring of an ultra-high voltage GIS disconnector switch.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A method for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector, characterized in that, include: Three external UHF sensors are arranged in the air chamber of the UHV GIS disconnector. The first external UHF sensor is placed on the upper end of the lower basin insulator of the air chamber, the second external UHF sensor is placed on the lower end of the upper basin insulator of the air chamber, and the third external UHF sensor is placed on the lower end of the lower basin insulator of the air chamber. When the time difference between partial discharge received by the first external UHF sensor and the second external UHF sensor is within the first preset threshold range, and the time difference between partial discharge received by the first external UHF sensor and the third external UHF sensor is greater than the second preset threshold, and the partial discharge signal in the gas chamber of the UHV GIS disconnector matches the characteristics of solid insulation discharge, then it is determined that there is partial discharge between the switching resistor insulation support rod or outer sheath and the equalizing ring in the gas chamber of the UHV GIS disconnector.

2. The method according to claim 1, characterized in that, The first preset threshold range is specifically 1ns to 6ns.

3. The method according to claim 1, characterized in that, The second preset threshold is 1 ns.

4. The method according to claim 1, characterized in that, The partial discharge signal in the gas chamber of the ultra-high voltage GIS disconnector conforms to the characteristics of solid insulation discharge, including: The partial discharge signal in the gas chamber of the ultra-high voltage GIS disconnector has a stable discharge phase, exhibits polarity effects, and has a dispersed amplitude.

5. A system for identifying partial discharge in the gas chamber of an ultra-high voltage GIS disconnector, characterized in that, include: The sensor module is used to arrange three external ultra-high frequency sensors in the gas chamber of the ultra-high voltage GIS disconnector. The first external ultra-high frequency sensor is placed on the upper end of the lower basin insulator of the gas chamber, the second external ultra-high frequency sensor is placed on the lower end of the upper basin insulator of the gas chamber, and the third external ultra-high frequency sensor is placed on the lower end of the lower basin insulator of the gas chamber. The identification module is used to determine that there is a partial discharge between the switching resistor insulation support rod or outer sheath and the equalizing ring in the gas chamber of the UHV GIS disconnector when the time difference between the partial discharge received by the first external UHV sensor and the second external UHV sensor is within a first preset threshold range, and the time difference between the partial discharge received by the first external UHV sensor and the third external UHV sensor is greater than a second preset threshold, and the partial discharge signal in the gas chamber of the UHV GIS disconnector matches the characteristics of solid insulation discharge.

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