Radiation crosslinking heat-shrinkable material ( referred to as heat-shrinkable material ) is a new kind of insulation material. Introduces the heat-shrinkable material types, technical performance and its application in substation, points out the selection of high quality pyrocondensation material will greatly improve the insulation level of substation.
Application of pyrocondensation material Substation Insulation Level
In recent years, with the continuous development of industry, the environment pollution is increasingly serious, the substation insulation protection requirements continue to increase, especially old substation insulation protection is becoming more and more important. In fact, substation pollution flashover, condensation flashover tripping, icing, small animals, bare busbar short-circuit power when the accident occurred, therefore, choose to use high quality insulating materials on the safe operation of the power system has great significance.
This paper aims to introduce the heat-shrinkable material and substation related technical parameters and it can solve some practical problems in substation, the radiation crosslinking heat-shrinkable material application in substation, for the power system to provide a new insulation protection means and new insulation materials.
1 types of heat shrinkable material
For substation busbar insulating heat-shrinkable sleeve of heat-shrinkable material with ( MPG ), heat-shrinkable composite insulating tape ( FJRD ), insulation anti cover, cable terminal head and creepage distance of growth regulator.
MPG with excellent insulation properties, good technological properties for substation busbar insulating shield.
Composite thermal insulation coating with FJRD namely, its structure by thermal layer and low melting point polymer adhesive layer, when in heating, the shrinkage, the melt, thereby being protective charged body seal, insulation integration. It is used for old substation spacing shortage, pollution flashover and serious ice cover and not easy to implement the insulating treatment place. Insulation protection box for the connections of the insulation protection, as well as the cabinet isolating switch, oil circuit breakers and other special contact protection.
Cable terminal head superior performance, convenient and quick installation, no need of special equipment and technology, has been widely used in electric power system, power cable attachment becomes the new development direction of.
Climb distance extender for solve the pollution level enhance the flashover problem. Generally speaking, as long as the original post insulator and porcelain bottle shrink corresponding size of umbrella skirt can solve these problems.
2 technical performance
Heat shrinkable materials for substation busbar busbar, does not affect the temperature rise
Xi'an Institute of high voltage switch cabinet of pyrocondensation material in the application of 1000A in temperature rise experiments show: in heat-shrinkable material ( MPG and FJRD ) coated junction bus, in the temperature measuring points under the same conditions, basic does not affect the temperature rise. In this context, ABB, American GE company, Siemens of Germany, the United States of America Westinghouse, both in its heat shrinkable materials application made for us the most convincing practical application technical illustration. Therefore, heat-shrinkable material on substation bus insulation protection will not affect its temperature rise, will not reduce the bus load flow.
( 2) heat-shrinkable material fire performance
In power system, indoor options by the insulating material are flame retardant. For Substation Insulation Protection heat-shrinkable material to rubber and polymer blends as the main body, add the excellent performance of the flame retardant, the experimental determination of the oxygen index is 32, has the very good from the fire self-extinguishing. To meet the power system of the flame retardant requirement.
( 3) heat-shrinkable material aging resistant performance
Power system for the electrical equipment needs to have long-term reliability, therefore, radiation crosslinking heat-shrinkable material beyond its other materials excellent performance for foreign power system application. We know, from the principle of thermal shrinkage, thermal properties and microstructure of nature, originating in the internal network of cross-linked structure, it is because of this reason, heat-shrinkable material aging resistance performance is better than the other insulating material. Shanghai cable Institute of Changchun heat-shrinkable material limited liability company product be accelerated aging experiment show that, the thermal aging life of up to 20 years, the company in 1984 in power systems using the thermal head has run safely for 13 years, in the artificial satellite application polyolefin heat-shrinkable material has been running for 21 years.
( 4) substation for heat-shrinkable material temperature resistance performance
Heat shrinkable material because of its special microscopic nature, after 158 + / - 2 DEG C, 168h thermal aging test, performance ( no great changes on the substation special series heat-shrinkable material ). Generally speaking, the substation busbar limit working temperature of 70 DEG c.. Therefore, substation special heat shrinkable material can meet the operation of substation on the temperature characteristics of the requirements.
3 application
Above we elaborated the heat-shrinkable material electrical, physical and chemical characteristics, the application of new materials in substation insulation protection can solve many practical problems.
( 1) effectively eliminate substation the prevalence of small animal short-circuit fault
Long-term since, small animals, foreign bodies in substation fault lap electrical accidents caused by technical personnel has been plagued with power supply system. The substation switch cabinet and junction bus implementation thermal insulation protection, so that the original conductor with high quality insulating properties, therefore, even as the protective laxity and small animals into the station, also won't happen for small animals caused by the short circuit tripping or combustion. The use of thermal insulating material, the 10KV switch cabinet electrical distance on bare busbar from 125mm down to 6mm, which can make the switch cabinet size shrinks, reducing switch cabinet cost, reduces the occupied area and the investment of civil engineering.
( 2) to prevent pollution flashover, condensation flashover, ice and other trip accident
Due to increasing pollution, more and more of the substation pollution level improve, and make the old substation fault rate increase. Therefore, the main bus and cabinet branch bus implementation of insulation protection, on the original post insulator joined the creepage extender, became the old substation mode effective transform method. Using this method, we have been on the Fujian lions 220KV pocket Hill substation, Zhangzhou region of Changshan substation was reformed, and plans to Mudanjiang Lianhua hydropower station main transformer low voltage part and temporary power of transformation. High temperature area Hydropower Station substation system, due to the relative humidity is big, there are also due to condensation flashover tripping accidents caused problems. The northeast cold area in the winter temperatures can reach 45 degrees, may also be due to icing caused by discharge of insulator, use of thermal insulation protection can solve these problems.
( 3) effectively prevent charged bare row caused by human casualty accident
In the old substation, the switch cabinet and the bus are not implemented insulation protection, have maintenance personnel body to be charged the accident injury. In heat-shrinkable material on substation bus, a branch bus and joint part of the implementation of insulation protection, can eliminate this risk, we of Jinling Petrochemical a substation the transformation is a response to such accidents are. Shanghai Shidongkou Power Plant on low-voltage distribution screen in three phase four wire bus platoon also conducted local insulating treatment.
( 4) to prevent salt fog and harmful chemical gas corrosion on the bus
Coastal zone of the salt fog and heavy industrial area of industrial waste gas, a corrosive action on busbar. In addition to its lower busbar load flow, but also prone to contamination conducting channel, thereby causing the pollution flashover. Heat shrinkable material has excellent resistance to acid and alkali, can solve this problem effectively.
( 5) the creepage distance increasing device is used for solving the pillar insulator insufficient creepage distance
220, 110, 66 substation outdoor, 35KV electrical device on insulator and indoor junction bus supporting insulator is often a result of contamination caused by serious shortage, pollution flashover. This requires only will shrink creep distance extender on a porcelain dress, can solve the problem.
The 4 ending
To sum up, heat-shrinkable material for substation insulation protection, safe and reliable in technology, construction is convenient, benefit an investment in long-term benefit. It reached a construction, comprehensive protection, long-term security purposes, for the development of new unmanned ( few people on duty ) substation safe operation and high failure rate of old substation provides a new effective method. Application of pyrocondensation material has become the substation improve insulation protection level development direction. |
