Method for positioning discharge fault of GIS air chamber of ultra-high voltage transformer substation

Abstract

The invention relates to the technical field of transformer substations, in particular to an ultra-high voltage transformer substation GIS air chamber discharge fault positioning method. Comprising the following steps: S1, determining a fault range point according to a protection tripping range; s2, collecting current data of each switch in a trip fault range point, comparing the current data to obtain the maximum current data in the range, and narrowing the range of a fault air chamber; s3, measuring the information of the fault gas chamber, and if the information of the fault gas chamber is different from the information of the normal gas chamber, preliminarily judging the fault gas chamber; and S4, based on the fault gas chamber preliminarily judged in the step S3, carrying out test verification according to the SF6 decomposer, and confirming the fault gas chamber. Compared with a traditional strategy, the method provided by the invention has the advantages that the fault point positioning time is greatly shortened, the working efficiency is improved, and the non-planned power failure time and the load loss are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of substations, and more specifically, to a method for locating a discharge fault in an ultra-high voltage substation GIS gas chamber. Background Art

[0002] With the rapid development of smart grid construction in my country, the construction of UHV power grid continues to deepen, and GIS (Gas Insulated Substation) plays a vital role in it. The GIS system provides a solid guarantee for the stable operation of the power system. However, in the GIS system, once the gas chamber on the bus is damaged, it may cause bus failure, which poses a serious threat to the safe operation of the entire power grid. GIS gas chamber internal discharge failure is usually caused by loose metal parts inside the tank, dirt along the surface or cracks, which causes insulation reduction, resulting in gas chamber discharge and tripping. When the GIS gas chamber discharges, the gas chamber S0 2 , H 2 S and other gas components will seriously exceed the standard. Figure 2 As shown. By testing its component content, the faulty air chamber is located. However, this method uses SF 6 Component detection instruments are usually expensive, and the testing cost and time are long. Although traditional fault location methods, such as acoustic positioning, were widely used in the early days, they are inefficient and have limited accuracy. Workers need to be distributed around GIS equipment and use the sound generated by the boost test to determine the location of the fault point. However, due to the echo and interference in sound propagation, it is often difficult for workers to accurately capture the fault sound, resulting in the need for repeated boost tests, which is not only time-consuming and labor-intensive, but may also cause unnecessary damage to the equipment. In order to overcome this problem, the vibration method has gradually become the mainstream method for GIS fault location. This method accurately determines the location of the fault point by monitoring the mechanical vibration signal generated by the GIS when the breakdown fault occurs. Although the vibration method has higher accuracy than the acoustic positioning method, it also faces some challenges. First, in order to obtain comprehensive vibration data, a large number of vibration sensors need to be arranged on the GIS equipment, which undoubtedly increases the cost and workload. Secondly, the vibration signal will be affected by many factors during the propagation process, such as material properties, structural layout, etc., which may cause signal attenuation or distortion, thereby affecting the accuracy of fault location.

[0003] The patent with announcement number CN106771927B discloses a GIS withstand voltage fault location method and a fault cause judgment method and location device using the method, which specifically include: 1) Photoelectric sensors with different numbers are provided to detect the signal of each gas chamber of the GIS combination electrical appliance; 2) The processing unit determines whether a light signal appears. If a light signal appears, 3) is executed, otherwise 2) is continued; 3) The processing unit sends the number and the cause of the fault to the fault alarm unit, and the fault alarm unit issues an alarm prompt. The present invention can not only determine which gas chamber has a fault, but also determine the cause of the fault and issue an alarm, thereby improving the accuracy of positioning and judgment. The patent with announcement number CN112014695A discloses a GIS equipment fault rapid location system and method. The system includes a signal acquisition module, a protection action behavior analysis and diagnosis module, and an ultra-high frequency partial discharge online monitoring module. The present invention analyzes and diagnoses the tripping information of the equipment in the station, outputs the GIS fault time, phase difference and positioning range information to the GIS UHF online monitoring system, and retrieves the GIS UHF sensor amplitude and discharge rate signal within the corresponding time, phase difference and positioning range through the dual-mode synchronous clock module. The GIS air chamber with the greatest possibility of failure is determined by the signal strength amplitude positioning method. On the one hand, the number of GIS UHF sensors retrieved is reduced, and on the other hand, the influence of interference signals is avoided, which significantly improves the positioning accuracy and efficiency of GIS equipment. However, this technology is highly dependent on sensors, but may be affected by the environment, and may cause omissions or false alarms.

[0004] The patent with announcement number CN105548810B discloses a busbar fault air chamber positioning method and device, which is applied to the GIS system. The GIS system includes two busbars, several air chambers arranged on the busbars, several switches connected in parallel between the two busbars, and external branches connected to the switches. When locating the busbar fault of the GIS system, the injected current of each external branch at the time of the fault collected by the fault recorder and the current distribution of each switch at the time of the fault are read, and the injected current of each external branch at the time of the fault is used to simulate the individual fault of each air chamber on the busbar. The current distribution of each switch is calculated by using the injected current of each external branch at the time of the fault. The current distribution of each switch calculated when each simulated air chamber fails individually is compared with the current distribution of each switch at the time of the fault collected by the fault recorder, and the simulated fault air chamber with the closest current distribution comparison result is determined as the fault air chamber. This application reduces the scope of micro-water testing of busbar air chambers and improves the efficiency of fault location. Since this technical document uses simulated fault current, there may be certain differences between the actual fault situation and the simulated situation. This difference may cause deviations between the simulation results and the actual fault situation, thereby affecting the accuracy of positioning.

[0005] In summary, the current GIS fault gas chamber positioning method has problems such as inaccurate positioning, low positioning efficiency, and high testing cost. Therefore, it is urgent to propose an efficient method for locating GIS gas chamber discharge faults in ultra-ultra-high voltage substations. Summary of the invention

[0006] Aiming at the problems of inaccurate positioning, low positioning efficiency and high testing cost in the existing GIS fault air chamber positioning method, this application proposes a method for locating GIS air chamber discharge fault in an ultra-high voltage substation.

[0007] The technical solution of this application:

[0008] A method for locating a discharge fault in an ultra-high voltage substation GIS gas chamber comprises the following steps:

[0009] Step S1. Determine the fault range point according to the protection tripping range;

[0010] Step S2. Collect the current data of each switch within the tripping fault range and compare to obtain the maximum current data within the range, thereby reducing the range of the faulty air chamber;

[0011] Step S3. Determine the information of the faulty air chamber. If the information of the faulty air chamber is different from that of the normal air chamber, preliminarily determine the faulty air chamber;

[0012] Step S4. Based on the faulty air chamber preliminarily determined in step S3, 6 The decomposed products were tested and verified to confirm the faulty gas chamber.

[0013] In a specific implementable solution, the current data of each switch within the tripping fault range is collected and compared to obtain the maximum current value within the range in step S2, which is completed by the data reading unit, current distribution calculation unit and current distribution comparison unit built into the GIS air chamber.

[0014] In a specific implementable solution, the data reading unit transmits the read current data to the current distribution calculation unit, which calculates the current data based on a divide-and-conquer algorithm and transmits the calculation result to the current distribution comparison unit to obtain the maximum current data.

[0015] In a specific implementable solution, the information in step S3 includes any one or more of temperature data, pressure data and a discharge signal spectrum.

[0016] In a specific implementable solution, the temperature data is obtained through a temperature reading unit and a temperature difference calculation unit built into the GIS air chamber.

[0017] In a specific implementable solution, the pressure data is completed by a pressure reading unit and a pressure difference calculation unit built into the GIS air chamber.

[0018] In a specific feasible solution, the discharge signal spectrum is completed by a built-in image acquisition unit in the GIS air chamber.

[0019] In a specific implementable solution, the discharge signal spectrum is divided into free metal particle discharge, suspended potential body discharge, air gap discharge inside the insulating part, surface discharge and metal tip discharge according to type.

[0020] In a specific implementable scheme, the information of the faulty air chamber in step S3 is different from the information of the normal air chamber, and is manifested in that the temperature data of the faulty air chamber is 7 to 8°C higher than the rated temperature data of the normal air chamber; the pressure data of the faulty air chamber is higher than the rated pressure of the normal air chamber; and the discharge signal spectrum of the faulty air chamber is different from the typical discharge spectrum of the normal air chamber.

[0021] In a specific practicable solution, in step S4, SF 6 Decomposition products include but are not limited to sulfur dioxide gas and hydrogen sulfide gas. The test verification conditions are to control SF 6 The decomposition product flow rate is 0.18 to 0.22 L / min, and the water flow rate is 0.45 to 0.55 L / min.

[0022] Beneficial effects of this application:

[0023] The present application first determines the fault range point according to the protection tripping range; then narrows the faulty air chamber range by the fault current; further determines the faulty air chamber preliminarily by measuring one or more information in the temperature data, pressure data and discharge signal spectrum of the faulty air chamber; and finally determines the faulty air chamber by SF 6 The decomposition test verifies and confirms the gas chamber at the fault point. The method provided by the present application can accurately locate the faulty gas chamber, avoiding misjudgment and missed judgment that may occur in traditional methods. At the same time, rapid positioning of the fault point can quickly restore power supply and reduce power outage time, thereby improving the reliability and stability of the power system. It can also reduce the number and duration of unplanned power outages, which is crucial to ensuring the continuity and satisfaction of users' electricity use; it can avoid or reduce load losses caused by power outages, and ensure the economic operation of the power system; it can promptly eliminate safety hazards and avoid further expansion of faults, thereby improving the safety of the entire power system. Furthermore, through accurate and rapid fault positioning, operation and maintenance personnel can quickly find and repair faults, reduce unnecessary inspections and maintenance work, and reduce operation and maintenance costs. It also improves the reliability of the power system and reduces the risk of system instability and power outages caused by faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Attached Figure 1 This is the process flow chart of this application;

[0025] Attached Figure 2 This is a diagram of the gas chamber components after the switch gas chamber of a 500KV substation of Anhui Company was discharged in 2019;

[0026] Attached Figure 3 This is the infrared temperature measurement diagram of the switch chamber of a 500KV substation of Anhui Company after discharge in 2019;

[0027] Attached Figure 4 This is the discharge trace of the horizontal insulation basin of the gas chamber bushing of the 5042 circuit breaker fault in a 500KV substation of Jibei Company in 2023;

[0028] Attached Figure 5 This is a diagram of the discharge type of the faulty gas chamber. DETAILED DESCRIPTION

[0029] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0030] A method for locating discharge faults in GIS gas chambers of ultra-high voltage substations, such as Figure 1 As shown, the following steps are included:

[0031] Step S1. Determine the fault range point according to the protection tripping range;

[0032] Step S2. Collect the current data of each switch within the tripping fault range and compare and obtain the maximum current number within the range, which is completed through the built-in data reading unit, current distribution calculation unit and current distribution comparison unit of the GIS air chamber. The data reading unit transmits the read current data to the current distribution calculation unit, which calculates the current data based on the divide-and-conquer algorithm, and transmits the calculation result to the current distribution comparison unit to obtain the maximum current data, thereby reducing the range of the faulty air chamber;

[0033] Taking the tripping of bus #2 of a 1000KV substation in Hebei in 2020 as an example, by checking the tripping report, it was found that the fault current of each switch was as shown in Table 1.

[0034] Table 1

[0035] Switch No. Fault current (secondary) T012 2.35A T023 2.136A T033 1.894A T053 1.885A T062 0.774A T073 0.749A

[0036] The tripping discharge chamber is T012-2 switch B phase. The above fault current shows that T012 has the largest current, which is 2.35A. The closer the switch is to the fault point, the greater the fault current. The inspection scope can be narrowed down by combining the fault current.

[0037] By adopting the above technical solution, the efficiency of fault detection is improved. Through automated data reading and calculation and analysis, the faulty air chamber can be quickly located, reducing the time and labor costs of traditional manual troubleshooting. By automatically collecting, calculating and analyzing the current data of each switch within the tripping fault range, the location of the faulty air chamber can be quickly and accurately determined, providing strong support for subsequent fault detection and maintenance.

[0038] Step S3. Determine the information of the faulty air chamber. If the information of the faulty air chamber is different from that of the normal air chamber, preliminarily determine the faulty air chamber;

[0039] During work, due to different test conditions at each site, temperature data, pressure data and discharge signal spectrum cannot be detected at the same time, but the more data measured, the more conducive to the determination of the faulty air chamber. Therefore, at least one of the temperature data, pressure data and discharge signal spectrum needs to be measured for abnormality. It can be understood that, for example, if the temperature data is abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the pressure data is abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the discharge signal spectrum is abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the temperature data and pressure data are abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the temperature data and the discharge signal spectrum are abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the pressure data and the discharge signal spectrum are abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the temperature data, pressure data and the discharge signal spectrum are abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the temperature data, pressure data and the discharge signal spectrum are abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged; for example, if the temperature data, pressure data and the discharge signal spectrum are abnormal, then combined with the current data in step S2, it can be determined that the air chamber has discharged.

[0040] Among them, the temperature data is completed through the built-in temperature reading unit and temperature difference calculation unit of the GIS air chamber; the pressure data is completed through the built-in pressure reading unit and pressure difference calculation unit of the GIS air chamber; the discharge signal spectrum is completed through the built-in image acquisition unit of the GIS air chamber.

[0041] The differences between the temperature data and pressure data of the faulty gas chamber and those of the non-faulty gas chamber are mainly manifested as follows: the temperature data of the faulty gas chamber is 7 to 8°C higher than the rated temperature data of the faulty gas chamber without discharge, and the pressure data of the faulty gas chamber is higher than the rated pressure of the normal gas chamber.

[0042] Taking the tripping of T062 switch in a 500KV substation of Anhui Company in 2019 as an example, the faulty gas chamber was determined by combining current data and temperature data. The gas chamber of phase B of the switch was discharged, the line protection was activated, and the bus differential protection was activated. The fault range was initially confirmed by measuring the current, and then the gas chamber within the fault range was subjected to infrared temperature measurement. The results are shown in the attached figure. Figure 3 As shown, the temperature is 38.2℃, which is higher than other air chambers. 6 The decomposition products were tested and verified, and the results are shown in the attached Figure 2 shown.

[0043] Take the failure of the 5042 circuit breaker in a 500KV substation of Jibei Company in 2023 as an example. Figure 4 As shown in the figure, the faulty gas chamber is determined by combining current data and pressure data. The 500KV Hunyuan switch station adopts 3 / 2 wiring mode and consists of 4 complete strings. After the fault occurred, it was found through on-site inspection that the B phase SF of the 5042 circuit breaker 6 The gas pressure increased to 0.76MPa (rated value 0.6MPa), and then dropped to the rated value after 2 hours. 2 and H 2 S seriously exceeded the standard. The mechanism opening and closing position indicator was in the opening position, and the explosion-proof membrane was intact. After opening the cover for inspection, it was found that the surface of the arc extinguishing chamber shield was black, and there were discharge marks on the lower surface of the horizontal insulating basin of the bushing. Figure 4 shown.

[0044] The faulty air chamber discharge signal is divided into free metal particle discharge, suspended potential body discharge, air gap discharge inside the insulating part, surface discharge and metal tip discharge according to the type; the discharge spectrum obtained by the image acquisition unit is compared with the typical discharge spectrum to determine the discharge type. The faulty air chamber discharge type is shown in Table 2 and Figure 5 shown.

[0045] Table 2

[0046]

[0047]

[0048] Step S4. According to SF 6 Decomposition test is performed to verify and confirm the fault point gas chamber, where SF 6 The decomposition products include but are not limited to sulfur dioxide gas and hydrogen sulfide gas; the test verification conditions are to control the decomposition product flow rate to 0.18-0.22 L / min and the water flow rate to 0.45-0.55 L / min.

[0049] Test SF 6 The cycle of decomposition products is based on the following:

[0050] According to Article 7.1 of the "1000kV AC Electrical Equipment Preventive Test Procedure" (Q / GDW 322-2009), 1000kV GIS equipment SF 6 The gas humidity detection cycle is 1 year.

[0051] According to Article 5.9.1.1 of the "Power Transmission and Transformation Equipment Condition Inspection and Test Procedure" (Q / GDW 1168-2013), GIS equipment SF 6 The reference period for gas humidity detection (with power on) is 3 years.

[0052] According to Article 5.8.1.1 of the "Power Transmission and Transformation Equipment Condition Inspection and Test Procedure" (Q / GDW 1168-2013), 110(66)kV and above SF 6 Circuit breaker SF 6 The reference period for gas humidity detection (with power on) is 3 years.

[0053] According to Article 5.8.1.1 of the "Status Inspection and Test Procedure for Power Transmission and Transformation Equipment" (Q / GDW 1168-2013), 6 This project should be carried out when one of the following conditions occurs: a) Measure once when the system is newly commissioned. If it is close to the caution value, measure again after half a year; b) Measure once within 48 hours to 2 weeks after new gas filling (replenishment); c) When the gas pressure drops significantly, the gas humidity should be tracked and measured regularly.

[0054] According to Article 9 of Annex 1 of the Guidance on Live Detection of Substation Equipment (Yunjianyi

[2014] No. 108), combined electrical appliances SF 6 Gas decomposition product detection cycle: (1) 500 kV and above: 3 years for operation and maintenance units; (2) Others, when necessary; (3) Within 1 week after new installation and A and B type maintenance and re-commissioning.

[0055] According to Article 9 of Annex 1 of the Guidance on Live Detection of Substation Equipment (Yunjianyi

[2014] No. 108), combined electrical appliances SF 6 Gas purity detection cycle: when necessary.

[0056] The method provided by the present application can accurately locate the faulty gas chamber, avoiding the misjudgment and missed judgment that may occur in traditional methods. At the same time, rapid positioning of the fault point can quickly restore power supply and reduce power outage time, thereby improving the reliability and stability of the power system. It can also reduce the number and duration of unplanned power outages, which is crucial to ensuring the continuity and satisfaction of users' electricity use; it can avoid or reduce load losses caused by power outages, ensuring the economic operation of the power system; it can promptly eliminate safety hazards and avoid further expansion of faults, thereby improving the safety of the entire power system. Furthermore, through accurate and rapid fault positioning, operation and maintenance personnel can quickly find and repair faults, reduce unnecessary inspections and maintenance work, and reduce operation and maintenance costs. It also improves the reliability of the power system and reduces the risk of system instability and power outages caused by faults.

[0057] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for locating a discharge fault in an ultra-high voltage substation GIS gas chamber, characterized in that: The steps include: Step S1. Determine the fault range point according to the protection tripping range; Step S2. Collect the current data of each switch within the tripping fault range and compare to obtain the maximum current data within the range, thereby reducing the range of the faulty air chamber; Step S3. Determine the information of the faulty air chamber. If the information of the faulty air chamber is different from that of the normal air chamber, preliminarily determine the faulty air chamber; Step S4. Based on the faulty gas chamber preliminarily determined in step S3, test and verify according to the SF6 decomposition product to confirm the faulty gas chamber.

2. The method for locating an ultra-high voltage substation GIS gas chamber discharge fault according to claim 1 is characterized in that: In step S2, the current data of each switch within the tripping fault range is collected and compared to obtain the maximum current value within the range, which is completed by the data reading unit, current distribution calculation unit and current distribution comparison unit built into the GIS air chamber.

3. The method for locating an ultra-high voltage substation GIS gas chamber discharge fault according to claim 2 is characterized in that: The data reading unit transmits the read current data to the current distribution calculation unit, which calculates the current data based on a divide-and-conquer algorithm and transmits the calculation result to the current distribution comparison unit to obtain the maximum current data.

4. The method for locating an ultra-high voltage substation GIS gas chamber discharge fault according to claim 1 is characterized in that: The information in step S3 includes any one or more of temperature data, pressure data and discharge signal spectrum.

5. The method for locating an ultra-high voltage substation GIS gas chamber discharge fault according to claim 4 is characterized in that: The temperature data is obtained through the temperature reading unit and the temperature difference calculation unit built into the GIS air chamber.

6. A method for locating an ultra-high voltage substation GIS gas chamber discharge fault according to claim 4, characterized in that: The pressure data is obtained through the built-in pressure reading unit and pressure difference calculation unit of the GIS air chamber.

7. The method for locating a discharge fault in an ultra-high voltage substation GIS gas chamber according to claim 4, characterized in that: The discharge signal spectrum is completed by the built-in image acquisition unit of the GIS air chamber.

8. The method for locating a discharge fault in an ultra-high voltage substation GIS gas chamber according to claim 4, characterized in that: The discharge signal spectrum is divided into free metal particle discharge, suspended potential body discharge, air gap discharge inside the insulating part, surface discharge and metal tip discharge according to the type.

9. The method for locating an ultra-high voltage substation GIS gas chamber discharge fault according to claim 1, characterized in that: The information of the faulty air chamber in step S3 is different from that of the normal air chamber, as shown in that the temperature data of the faulty air chamber is 7 to 8°C higher than the rated temperature data of the normal air chamber; the pressure data of the faulty air chamber is higher than the rated pressure of the normal air chamber; and the discharge signal spectrum of the faulty air chamber is different from the typical discharge spectrum of the normal air chamber.

10. The method for locating an ultra-high voltage substation GIS gas chamber discharge fault according to claim 1, characterized in that: The SF6 decomposition products in step S4 include but are not limited to sulfur dioxide gas and hydrogen sulfide gas. The test verification conditions are to control the flow rate of SF6 decomposition products to 0.18-0.22 L / min and the water flow rate to 0.45-0.55 L / min.

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