New Solid-state Short-circuit Current Limiter In Power System Applications

The national economy of China develops so fast in recent years that there is great demand of electrical energy. Along with that the power network expands fast and becomes more and more complex, the fault current has increased greatly which has become one of the most important restriction for the further development of power system. So it is necessary for study on the fault current limiters (FCL).Compared to the research on the FCL, the questions on how to apply FCL in the power system are discussed less. But they are very important. If they are not solved well, they may cause some new problems when FCL have been applied in the power system.This paper focuses on these problems above. First, this paper summarizes some existing technologies of fault current limiter at home and abroad. Second, this paper expatiates on the advantage of the transformer coupling solid state fault current limiter with bypass inductance by comparing two kinds of SSFCL (solid state fault current limiters) topologies on the aspect of control method, cost and the harmonic it may cause in the power system. In the third chapter, the optimal location assignment and design of SSFCL applied in power system are discussed. The results of simulation by BPA and PSASP are proposed. Chapter Four discusses about the effect on the power system after SSFCL application as follows: ①the effect on the distance protection,②he effect on the transient stability of power system, ③the effect on the steam turbine axial torsion vibration, ④the effect on the voltage sags, ⑤the effect on the electromagnetic environment, ⑥the effect on the power quality and so on. In the fifth chapter, there is a summarization of the paper and the trend of SSFCL study is predicted.