A study on modeling of high-voltage short circuit current limiter in electromechanical transient simulation

A model of FACTS based high voltage short circuit current limiter(HV-SCCL) applicable for electromechanical transient simulation of large power grid is established with the user-defined program of PSASP software, which developed by China Electric Power Research Institute(CEPRI). Through comparing periodically line current and its variation rate with the corresponding short-circuit current (SCC) threshold, this model decides whether thyristor protected series compensation(TPSC) would be switched on or off and consequently control its capacitive reactance value. The effectiveness of the proposed model is proved in a 4-machine system. Furthermore, its effects for limiting SCC and influences on system stability under conditions of different reactance parameters of SCCL are presented and analyzed in East China Power Grid (ECPG).The results indicate that parameter selection of reactor in the SCCL applied to transmission line should not only consider an anticipative SCC limiting factor but also take into account those restrictions of series compensation degree, while the reinserting time of TPSC is also one of the critical elements required special attention in stability studies. Furthermore, the observed dynamic behaviors imply that its impacts on small signal stability should be concerned especially when the protection failure or delayed reclosing of TPSC happens, which are being studied.