The practice of SF electrical equipment in the safe operation of the power grid Dou Weidong (Dingxi Power Company of Gansu Province Electric Power Company, Dingxi 743000, Gansu, China) Established relevant regulations and systems to discuss the maintenance and safe operation of SF gas and SF electrical equipment. The safe operation of the equipment provides the basis.
The city is awakened by open-air substations, a city with high altitude and high altitude. - 4) Aluminum trifluoride - Bookmark1 1 Overview With the rapid development of electric power technology and the construction and renovation of "two networks", the use of SF electrical equipment is rapidly increasing. plus. This kind of equipment meets the requirements of no oil, and meets the requirements of miniaturization and automation. Therefore, S6 electrical equipment has been widely used, common SF electrical equipment: S6 circuit breakers, gis closed combination appliances, SF voltage transformers, S, current transformers, in addition to S6 insulated transformers, and various types of high voltage Tubes and so on. Although sf electrical equipment has good insulation and arc extinguishing capabilities, accidents can occur if improperly used, so we must attach great importance to the safety of S6 electrical equipment.
Advantages of SF gas and SF electrical equipment SF gas has high dielectric strength and is conducive to miniaturization of electrical equipment.
SF gas arc extinguishing ability, SF circuit breaker contacts burning slightly, long maintenance cycle.
The recovery speed of the medium is particularly fast, and the cooling characteristics are good. The S6 circuit breaker's fracture voltage can be made very high, and the performance of breaking the near area fault is particularly good. It is safe and reliable, and has a long service life.
The SF circuit breaker has a large breaking capacity. When the small inductor current and the small capacitor current are disconnected, the arc extinguishing characteristics are good, and an operation overvoltage is not suitable.
The SF gas arc decomposing field does not contain carbon and other substances that affect the insulation ability, and there is no risk of fire. Therefore, this type of circuit breaker allows for multiple times of breaking, simple installation and operation, small operation and maintenance, and safety and reliability.
The advantage of SF combination electric appliance (GS) scoop minimizes the floor space and space volume of the entire distribution device, and the structure is very compact. The 110kV GIS covers only the load center, which is even more important.
The fully enclosed electrical structure is not affected by various natural environmental conditions such as pollution, rain and thunder, dust and salt spray, which reduces the possibility of equipment accidents, and is particularly suitable for high altitude areas with industrial pollution and bad weather.
Easy and quick installation can greatly shorten the installation period. Since the GS has been developed into a three-phase common, compound, and intelligent direction, it is generally enclosed in a grounded metal body by a unit such as a complete clarifier, disconnector, grounding switch, transformer, arrester, busbar, and connector. composition.
Operation and Maintenance Practices of SF Electrical Equipment 41SF Gas Overview S6 gas has high dielectric strength and good arc extinguishing performance, but it is generally installed in electrical equipment with higher pressure (such as 03MPa and 06MPa). Although SF gas is theoretically considered to be safe, non-toxic and non-combustible, due to S, the gas is colorless and odorless, chemical properties are very stable, and the molecular weight at 101325 Pa20C is 6 16gLSF with a molecular weight of 14605 amines as in 1985 International The proportion of atomic weight is about 5 times that of air, and it is easily deposited on the bottom of the space. It is not easily diffused and inhaled too much. It can cause dizziness, vomiting, etc., and may cause death due to suffocation in severe cases. At the same time, during the preparation of S6 gas, some toxic substances may be mixed in. In the S6 electrical equipment, corona, spark and arc discharge can also produce a variety of toxic, corrosive gases and solid decomposition products. These gases are mainly fluorinated thionyl (SF), sulfonyl fluoride (phantom F), sulfur tetrafluoride (SF), sulfur tetrafluoride (SF), sulfur dioxide (sn disulfide disulfide (SF0) Dioxane, decafluoride, disulfide (SF0), etc.; The solid decomposition products mainly include the two methods of qualitative and quantitative detection of leakage and leak detection of copper fluoride (cuf) and difluorodimethyl silicon 42SF electrical equipment. Generally, high-sensitivity probes are used to detect the leaky parts of the equipment, which are characterized by sound and light alarms and convenient positioning.In the field practice, qualitative leak detection is more practical, including: simple qualitative leak detection, pressure drop, segmentation and positioning Local accumulation method: The simple qualitative method uses a general leak detector to detect the sealing surfaces of all equipment components and extremely suspicious places at the pipe joints, and the method is simple and can find relatively obvious local leakage. The pressure drop method is used with precise pressure. The gas pressure is measured on the meter and it is measured several days or dozens of days, combined with temperature conversion or horizontal comparison to determine whether the pressure drop occurs.The segmentation and positioning method is applicable to the three-phase SF gas circuit together with the electrical equipment. After the SF gas system is divided into several parts and then leak tested, the blindness can be reduced.The partial accumulation method is to wrap the measurement part with a plastic cloth, and after a few hours it is measured with a leak detector to measure whether there is leakage of SF gas in the plastic cloth. Qualitative leak detection methods that are more commonly used today.
In practice, it is proven that: SF electrical equipment is vulnerable to leakage of the main parts are: the detection port, weld, aeration nozzle, flange connection surface, pressure gauge connecting pipe, sealing base and so on.
Quantitative measurements include bottle-mounted leak detection and partial dressing, which should be performed 24 h after inflation. HEA2012 leak detector or LE2000 leak detector can be used as a quantitative measuring instrument, which is safe and convenient and ideal. Quantitative measurement criteria for the annual leakage rate of not more than 1%. In addition to ensuring the integrity of the SF electrical equipment gas pressure operation monitoring equipment, regular inspection of SF pressure gauges, densitometers and other monitoring equipment, regular leak detection of SF electrical equipment Test, find fault points in a timely and accurate manner, and formulate treatment measures. Conditions can also be installed in the SF high pressure indoor oxygen measuring instrument, alarm when the oxygen content is too low.
In general, the oxygen content should not be less than 18%. 43 Measurement of the micro water content The measurement of the micro water content of the SF gas should be performed after the humidity in the air chamber is stable. The enclosed combination appliance should generally be performed after the air charge 241. P5 dew point micro water tester or DP9-S-SF water tester can be used for testing.
Table 1. Requirements for the moisture content in the isf6 gas (ppv/v) Item Breaker Interrupter Chamber Other chambers Acceptance of overhaul After overhaul Operation with different instruments When measuring the same device, it is possible to obtain and use the same device. Gas piping is related to factors such as operation, so it is recommended to use the same instrument for measurement to ensure the comparability of test data.
Before measuring the SF gas in the gas chamber of the SF electrical equipment, dry the gas fittings of the test equipment. Otherwise, the accuracy of the test data will be affected.
The safe operation of 44SF electrical equipment At present, our company's 110kV and below substations in the "four remote"
Based on the mature technology, the unattended operation mode is being vigorously promoted. Whether the SF electrical equipment can operate safely and reliably is inextricably linked with the manufacturing quality, installation quality, operation and maintenance, and maintenance quality of the equipment. It is proved in safety production practice that the pressure drop of SF electrical equipment is a relatively common phenomenon, and sometimes falls below the alarm pressure (eg, the gas pressure of the GS of the Dingxi Substation and the 1102 switch of the Xintian Substation is reduced) Some components of SF electrical equipment may leak. The drop in gas pressure will inevitably reduce the dielectric strength and arc extinguishing ability of the SF gas, posing a serious risk to the safe operation of the equipment. Therefore, it is very important to accurately monitor the pressure of SF electrical equipment in real time. When the pressure is reduced or frequently suppressed, the transmission of the signal shall be timely and reliable, and the intelligently displayed abnormal data shall be notified to the on-duty personnel and maintenance personnel for timely processing. The sf electrical equipment in operation should generally measure the gas moisture content every three months. Because the moisture content of the gas increases with the increase of the outside air temperature, especially in the summer, the detection of the moisture content of the gas should be strengthened. If there is a condition, the SF electrical equipment shall be put into the on-line detection system for air pressure and moisture.
5 Training of staff and perfection of protective equipment Different data i This may be related to the performance of the instrument itself, but also when blishl breathe fresh air and wash hands, face, etc. with water: enkUetbookmark2 With the development of power technology, new products New technologies are constantly appearing and rapidly developing, especially sf electrical equipment. The equipment is small, complex and intelligent, and its technology is high. Therefore, we should provide education and training for staff and we must make every staff understand sf gas. The basic characteristics, master basic theoretical knowledge of sf electrical equipment and safety requirements for working on sf electrical equipment, proficiency in relevant technical regulations, process standards and operating procedures, so as to enable the staff to operate and maintain and repair work handy, so that SF Electrical equipment plays its role better. In addition, the staff's self-prevention awareness should be strengthened and their protection capabilities should be enhanced (eg, when the outdoor sf electrical equipment leaks, close to the sf electrical equipment from the upwind, wear long-sleeved overalls when working, etc.) and pay attention to issuing protective equipment for workers. , If equipped with anti-virus breathing apparatus, special protective clothing (used when the equipment is dismantled and overhauled) uses rubber gloves. There should be sufficient water in the substation. After the personnel contact the sf gas, attention should be paid to the work on the 6SF electrical equipment. Gas leakage of the SF electrical equipment is difficult to avoid. Due to the manufacturing quality and installation process, the aging of the sealing element and other reasons will appear. Leakage of gas and the infiltration of water are also common.
Gas leakage and moisture infiltration are the key factors that affect the long-term safe operation of S6 electrical equipment. Although S6 gas is theoretically considered to be safe, non-toxic, and non-combustible, due to excessive inhalation of SF gas, it can lead to dizziness, vomiting, etc., and severe death may occur due to suffocation. At the same time, during the preparation of S6 gas, some toxic substances may be mixed in. During the operation of the switch, the arc generated will also have an effect on S6, resulting in toxic substances; therefore, high attention must be paid to the operation and maintenance.
Before SF electrical equipment overhaul work should do a good job of preventive measures and medical rescue measures.
When the S6 electrical equipment needs replenishment, the new S6 gas should be accepted according to the new gas quality standard. The purity of the new S6 gas should not be less than 99.8% The purity after charging the equipment should not be less than 97% of the carbon tetrafluoride, air, moisture, Eight indicators such as purity and acidity should meet national standards. Before inflating, all lines must be flushed. After inflation, the air pressure is slightly higher than the required value in order to test the moisture content. The detection of moisture content should be carried out by professionals using special instruments and prevent moisture from infiltrating during on-site inspection. When the equipment is filled with S6 gas, the relative humidity of the surrounding environment should be dismantled and repaired before the SF electrical equipment is overhauled. The staff should be trained with specific safety technical knowledge, and the SF gas should also be inspected. According to the toxic gas content, take safety precautions. Maintenance personnel should wear protective clothing and wear gas masks as required. After opening the equipment cover, all personnel on the site shall temporarily evacuate the site for 3mn to remove the adsorbent and remove the dust. The maintenance personnel shall wear a gas mask and protective gloves.
The gas in the equipment must not be released to the atmosphere. It should be taken by a purification device and used only after it has been processed. The equipment is vacuumed and flushed with nitrogen for 3 times before the equipment can be overhauled.
The operator should stand on the windward side when recycling.
When the SF electrical equipment is reinstalled, the sealing groove surface should be clean and free from scratches, and the sealing ring is generally O type. The gasket (ring) produced by special formulas of high-quality materials such as neoprene rubber, ethylene propylene rubber, and fluorine rubber should be used. The used sealing gasket) must not be used anymore. When applying the sealing grease, do not allow it to flow into the inside of the gasket (ring) to avoid contact with the SF gas.
When overhauling SF electrical equipment, the staff shall strictly follow the work site, work scope, precautions, and danger points listed on the work ticket, the three measures and the danger analysis card, and the inspection process must be standardized. The responsibilities of staff members, the strictness of the implementation of rules and regulations, technical standards and technical standards should all be regulated and quantified so that they can be followed by rules and evidence.
7 The management of SF electrical equipment is strengthened. S, equipment management, maintenance of SF electrical equipment, inspection of S6 electrical equipment, S6 gas detection, test equipment, safety equipment, etc. shall be staffed, regularly inspected, regularly checked, and implemented at all levels. Managerial responsibility. The spare S6 gas should be stored in a spacious, well-ventilated environment and managed as well as the operating equipment. A sound safety management system should be established and the staff should strictly implement this system.
8 Conclusion The operation practice over the years has proved that the use of sf electrical equipment in our office substation has made new breakthroughs in safe operation. At the same time, the S6 related system formulated by the Dingxi Power Company of Gansu Province has been implemented and implemented in accordance with standards and regulations. In order to find out a lot of problems, to eliminate the problem in the bud, to provide a strong basis for the elimination of hidden dangers of electrical equipment, thus ensuring the safe and reliable operation of electrical equipment, providing a strong guarantee for the company's safe production.
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