911 / 2019-04-30 16:33:05

Influence and Setting of H-bridge Cascade SSSC on Line Distance Protection

H-bridge cascaded SSSC,distance protection,PSCAD/EMTDC,fundamental frequency dynamic impedance,setting strategy

SSSC is one of the series compensation device, which inevitably affects line distance protection. In this paper, the influence of H-bridge cascaded SSSC based on actual engineering parameters on system distance protection is investigated. Firstly a detailed model of H-bridge cascaded SSSC and its control is proposed, and then the additional impedance characteristics in measuring impedance is analyzed theoretically under different fault types, and finally the correctness of the theoretical analysis is verified by combining time domain simulation in PSCAD/EMTDC. The research results show that when H-bridge cascaded SSSC is in faulty loop, different compensation modes and compensation degree have different effects on the distance protection. Aiming at the above effects, based on the concept of SSSC fundamental frequency dynamic impedance, a new setting strategy is proposed. The time domain simulation model is used to verify the effectiveness of the strategy.