Mechanism Research On IGCT Based Fault Current Limiter

The short circuit volume of grid and magnitude of short circuit current all increase continuously with the growth of power system's capacity. Short circuit current will directly influence the choice of electric equipment and the safe and stable operation of power grid. There are great demerits in traditional short circuit limiters, and it is an urgent task for us to design new current limiting schemes and devices. A new IGCT based fault current limiter is presented and a simulation using MATLAB is carried on the basis of analysis of its working mechanism. Results from the simulation show that the device can effectively limit short circuit current, reduce voltage sag and improve power quality. Exhaustive formular deduction and theoretical analysis are made from two aspects, the first one being power characteristics of system with FCL installed, the second one being the critical eliminating angle and the mechanism of FCL's influence on transient stability of power system is explained theoretically in a rigorous may on the foundation of proposed transient model of FCL. Finally, the design of software and hardware of control system are given.