Research on the influence of compound fault current limiter hybrid multiplexing TCSC on transient recovery voltage

The influence of thyristor controlled series compensation (TCSC) on the transient characteristics of transmission lines needs to be studied urgently. Firstly, the structure and function of compound FCL and TCSC are analyzed. Secondly, based on the background of 500 kV extra -high voltage demonstration line, a single-phase ground fault equivalent model of ultra -high voltage line with FCL and TCSC is established. The influence of FCL hybrid multiplexing TCSC on the breaking characteristics of circuit breakers is studied. Based on the Laplace transform and the equivalent parameter concentration circuit, the influence of the fast switching time and the current limiting ratio of the FCL on the transient recovery voltage is analyzed. The influence mechanism of different modes of FCL on transient recovery voltage is obtained. The research scheme of FCL instead of FSC is proposed, and the change rules of transient recovery voltage and rise rate RRRV under different compensation degrees are compared. The results show that under the same compensation degree, the FCL replaces the FSC to reduce the peak value of the transient recovery voltage and reduce the RRRV over -standard condition, which verifies the feasibility of replacing the FSC with FCL. A new design scheme for extra -high voltage series compensated transmission lines is provided.