The effects of a fast switching fault current limiter on distance protection

This work investigates the impact of a fast switching fault current limiter (FCL) on a distance protection scheme. The FCL is modeled utilizing GTOs to insert a resistive impedance in and out of the protected line. The examination is performed by analyzing the transient response of distance relay elements with and without the presence of the FCL in a protective scheme. Relay selectivity is explored while placing the FCL in front and behind the relay element. Furthermore, problems such as multiple tripping and nuisance tripping are investigated and solutions to these problems are addressed.