The Application Research Of A New FCL In Power System

With the development of power system and modern industry, the scale and capacity of power system is expanding, the system’s short-circuit capacity also is rising, and the grid short-circuit current is increasing. In addition, the scale of power system is rapidly expanding, the interconnection of regional power grid become more and more close, the medium-voltage system transformer’s capacity is increasing, and small-capacity power also be merged into the power grid, on the one hand, which effectively improve the power net’s transmission capacity, but on the other hand has made the short circuit current capacity rapidly growed. The power system short circuit current level is increasing steadily, which bring a lot of harm to the safe operation of power grid and users, so effective measures must be taken to limite the short circuit fault current of power system. Currently, the focus of research at home and abroad for application of high pressure and ehv system’s FCL is developed, because its comprehensive performance is good, and broad prospect of application. Domestic and international has some universities and colleges, enterprises, institutions and researches in carrying out the work. Some foreign countries already have some of the low-pressure equipment in hang net’s commissioning. Therefore, the application of fault current limiting used in power system has become the new frontiers in the century one of grid technology.This paper proposes a new type of FCL:at first, the new FCL’s topological structure and working principle are simply introduced.On this basis, the transient process is analyzed by simulating, and the working performance is verified. Finally, the power characteristics and the power-angle curve of the system with FCL in various cases are analyzed.Furthermore, the mechanism of FCL’s influence on transient stability of power system is given. Based on the above research, this kind of FCL can limit the short-circuit current first shock peak and steady-state peak rapidly and effectively, which verify the FCL is feasible.The simulation results show that FCL can not only greatly reduce the transient swing amplitude of the rotor,but also expand the critical eliminating angle. It is an active way to improve electric power system transient stability by installing FCL in power system.