Effect of the series resonance LC tank on the Mitigation of fault current in radial distribution networks

This paper proposes a novel Fault Current Limiter (FCL) for the application on power systems to control voltage sags at the Point of Common Coupling (PCC) during faults. This new FCL is a resonance transformer, whose primary side is connected to a series capacitor and transmission line. Also, the secondary side of the transformer is switched by a semiconductor device to change the impedance of the primary side of the transformer. The main control component is a fast-closing switch connected in parallel with the secondary side of the transformer, which is driven by the power electronic switch. It can respond within 1 msec. When a fault occurs, the switch closes and bypasses the transformer secondary side and fault current is limited by the reactor. So, by increasing the existing resonant frequency, the fault current is limited. The simulated and experimental results show that it is feasible to develop the FCL with low cost and high reliability. The experimental results show the capability of the proposed FCL, too.