Effect of post insulator insulator
High voltage insulator wire to connect one end of the tower hung a lot of disk, which is to increase the creepage distance, usually made of glass or ceramic, called insulators. In order to prevent dust and other dirt on the surface of the insulator is attached, forming pathways across the insulator breakdown voltage is increased. Therefore, the creepage distance is the surface, creepage distance, discharge distance along the surface of the insulation is called the leakage distance of creepage distance of creepage distance = surface distance / maximum system voltage. According to varying degrees of pollution, heavy pollution area the creepage distance is 31 mm / kv. Zero value insulator refers to the potential distribution of insulator is close to zero or equal to zero insulator in operation. Zero or low value insulator effect: insulation line wire depends on the insulator string, due to manufacturing defects or the role of the outside world, the insulation performance of insulators will continue to deteriorate when the insulation resistance is reduced or zero called low or zero value insulator. We have on line detection, zero or low value insulator proportion up to about 9%. This is the line lightning trip rate, another major reason for the high. The insulator is smooth, can reduce the effect of capacitance between the wires, in order to reduce the loss of current. The characteristics of insulator
1, post insulators are in line with GB8287.1 "high voltageporcelaininsulatorspillar technical conditions" and "Regulations of anti pollution GB12744, outdoor bar strut porcelain insulator", also conforms to the international standard IEC168 "nominal voltage greater than 1000 volts and users of the system in outdoor ceramic or glass pillar insulator test" and "IEC publication 815 insulators under pollution selection guidelines" provisions.
2 insulator, high mechanical strength, stable and reliable operation.
3, low temperature and good mechanical properties of insulator.
Low temperature mechanical performance test of products, change the temperature of the cold winter outdoor simulation in the Songliao water resources commission of water science laboratory, freezing test of ZSW1-110/4 type insulator. After a few times after temperature cycle, the low temperature will try to do crystal bending failure test. The test results show that the flexural strength of insulators compared with room temperature had no obvious change in -40 C.
4, excellent anti pollution performance.
Insulator pollution resistant performance mainly depends on the structure and product shape umbrella skirt. It has done a lot of work. Through the design optimization, optimization of artificial pollution test and natural pollution test optimization, and finally determine the insulator with edge size and white, under the umbrella umbrella. With the development of the umbrella rated voltage 126kV, 252kV bending load is not less than 12kV, creepage distance of insulator 25mm/kV, 0.12mg/ cm in 2 ESDD, long-term maximum operating voltage tolerance, the creepage distance of insulator III level, IV level can withstand ESDD contamination. Rated voltage of 550kV for the specific creepage distance of 25mm/kV insulator in 0.06mg/ 2 cm ESDD under long-term operation. Tolerance level of insulators in the leading domestic, its tolerance of ESDD value higher than the same size, climb from the umbrella skirt of similar products 1/3. The Northeast Electric Power Research Institute of insulation of artificial pollution withstand voltage test results show that the creepage distance of 31mm/kV insulator salt density is the highest tolerance 0.25mg/ 2 cm.
5, the high level of earthquake resistance.
Rated voltage 252kV, 550kV insulator, anti earthquake performance test of intensity level 9 in Beijing Institute of water conservancy and hydropower, the sample intact.
6, low radio interference.
Insulators with rated voltage of 550kV, at 1.1 times the maximum operating voltage, interference of less than 500 V, sunny night without visible corona, visible corona voltage up to 450kV.
