The Study Of Lightning-stroke Overvoltage On Substation Based On ATP-EMTP

Along with our country’s electric power system voltage level, 500 kV substation has become the hub of power system in our country. If the lightning disasters occur, light affect the normal operation of the power system, or will cause electrical components damage caused large area power outage. And because most electrical equipment within the substation no response ability, once the lightning disturbance and damages, late repair work is more difficult. the substation lightning protection performance of the safe operation of power system plays an important role, substation require reliable lightning protection measures and so on 500 kV substation lightning overvoltage protection study is very necessary. The source of the transformer substation lightning invasion wave mainly include: violent ray substation, Ray waves along the transmission wires to the substation. Because the probability of lightning transmission conductor is far greater than lightning hitting substation, transmission line lightning of caused great threat to the safe operation of substation. In related engineering planning and design process of power system, the study of transmission line lightning strike thunder electric wave invasion of substation, by the electrical facilities in the local station withstand overvoltage. Determine the distribution and change rule of overvoltage in electrical equipment, and various electrical equipment in a substation insulation coordination of scientific and reasonable, from a technical and economic restrictions on lightning invasion wave overvoltage, in order to reduce equipment insulation level, effectively reduce the manufacturing cost, reasonable compression project cost.In this paper, a 500 kV substation in Sichuan province as the research object, through the ATP- EMTP simulation software on the lightning overvoltage simulation research. This paper studies the main content of:(1)To establish the simulation model, including lightning model, tower model and arrester model, electrical equipment within the station model and transmission line model and so on.(2)To determine the corresponding simulation parameters of electrical equipment, application of ATP- EMTP transient simulation software for lightning simulation calculation. And by studying the different ground lightning with different substation operation mode, the equipment within the station lightning overvoltage calculation and analysis, find out the most serious situation for substation hazards.(3)Analysis: nearly area ground lightning tower(#1) within the substation lightning over-voltage produced by some of the electrical facilities than far area ground lightning tower(#6) is much higher; Different substation operation mode also affects the size of the overvoltage in electrical equipment, under the operation mode of double variable, all equipment within the station on the lightning overvoltage minimum, and single variable under the operation mode of lightning overvoltage biggest; By adding lightning arrester on bus and not add lightning arrester, lightning overvoltage value detected by vary widely; All electrical equipment within the station transformer in overvoltage of larger, at the same time, the lightning arrester before and after the transformer the minimal variation in the overvoltage.(4)Hammered out the distribution and change rule of overvoltage in electrical equipment, and various electrical equipment in a substation insulation coordination of scientific and reasonable, determine different electrical equipment within the substation insulation intensity, and the calculation of the insulation of the electrical equipment in determining the strength of the insulation of the margin, and puts forward some Suggestions on lightning protection of substation.