Method to determine wave resistance of impulse voltage generator for lightning impulse test

XUAN Yao-wei, LE Yan-jie, ZHANG Na-fei, LU Zhi-fei

(State Grid Zhoushan Power Supply Company, Zhoushan 316000, China)

Abstract: In the lightning impulse test, the wave resistance(front resistance denoted by Rf  and time to half-value resistance denoted by Rt) of impulse voltage generator should be adjusted in order to make the impulse waveform comply with the standard of IEC 60060-1: the standard waveform should have a front time denoted by tf of 1.2μs with the tolerance is ±30% and a time to half-value denoted by tt of 50μs with the tolerance is ±20%. Aiming at determining the wave resistance of impulse voltage generator quickly, the equivalent discharging circuit of the impulse voltage generator was analyzed mathematically, then non-linear equations for solving Rf and Rt were established and solved by hybrid genetic algorithm. After obtaining the numerical solution of Rf and Rt, the discharge circuit was simulated and analyzed by using Matlab. Finally, the field test was carried out in the high voltage test hall to verify the simulation results. The results indicate that the method to determine the wave resistance is effective, and can provide theoretical guidance for field test personnel to reduce the equipment debugging time.