Required limiting impedance and capacity of fault current limiter installed in customer system with synchronous generator

We investigated the required limiting impedance and capacity of a fault current limiter (FCL) installed at an incoming feeder of a customer system with a synchronous generator in a utility distribution system. It was assumed that two types of FCL were installed, i.e. a resistive type (R-type) FCL and an inductive type (L-type) FCL. A fault current out of the customer system and a voltage in the customer system were calculated following a three-phase, short-circuit fault occurrence. It was found that the required type of FCL and the required limiting impedance depended on the rated capacity of the generator in order to obtain the suppression of the fault current under 0.1 kA(s), and to maintain of customer voltage between 85 and 100% of the nominal voltage (6.6 kV). The capacity of FCL consisting of the smallest limiting impedance is discussed. (c) 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.