Residual voltage test method of controllable metal oxide surge arrester

The controllable metal oxide surge arrester is a kind of new electrical equipments which can deeply reduce switching overvoltage in UHV/EHV transmission system. Because of its unique structure, the conventional residual voltage test method could not be used to validate the protection effort of the controllable metal oxide surge arrester. It is necessary to find out an appropriate residual voltage test method for the controllable metal oxide surge arrester. Considering the controllable metal oxide surge arrester characteristics, the lack of conventional residual voltage test method was discussed and the residual voltage test requirements of controllable arrester were given. Based on theoretical analysis, a parallel modulated wave capacitor was used in the existing residual voltage test circuit to improve the voltage waveform. A measurable residual voltage test method for the controllable arrester was given. Through the simulation and test, the feasibility of the approach advocated in this paper was verified.