The Research Of The Probability Of Establishing Arc And Trip-Out Rate Due To Lighting Stroke Of Interrupter Lightning Protection Gap Under Airflow Stock

Transmission line is an important part of the power distribution of power grid. Since most of the transmission lines are set up on the ground, and the conventional measures of lightning protection has certain limitations, the transmission lines are therefore stroke by lightning severely. Especially, the power distribution of power grid stroke by lightning is more serious in the complicate topography of the frequent lightning area of the southern China, which causes great economic losses. Since the lightning protection level and trip-out rate due to lightning stroke are an important index evaluating transmission line stroke by lightning, it is necessary to calculate accurately the trip-out rate due to lightning stroke of interrupter lightning protection gap circuit.This article researches on the interrupter characteristics of a new interrupter lightning protection gap, which is based on the theory that airflow stock in the semi-closed chamber can interrupt rapidly, and the calculation of trip-out rate due to lightning stroke of interrupter lightning protection gap circuit. By the analysis on the interrupter characteristics under airflow stock, the mathematical model of interrupter under the airflow stock is established. Use the computational fluid dynamics to model and simulate the airflow field in the chamber, and get the interrupting time of interrupter lightning protection gap by analysing the temperature field distribution; obtain the response time of interrupter lightning protection gap and interrupter characteristics by the lightning stroke test and interrupting test of small power frequency; establish the probability of establishing arc under the airflow stock and lightning stroke mode of transmission lines, and put forward a new kind of algorithm of lightning trip-out rate that takes induction lightning stroke into consideration. After comparing with the original procedures and actual operation results, the calculation results based on the new algorithm is more consistent with the actual results, which provides a useful basis for the application of the new interrupter lightning protection gap in the practical engineering.