Transmission line protection based on travelling waves

Abstract

Major problem of tripping signal of a relay based on steady state component does not warranty faster tripping schemes for protection of extra high voltage transmission lines. Proposed work has made an attempt to find solution to the problem of fault detection and location by relay using post fault high frequency signals. Transmission line protection using travelling waves generated at the time of fault are used as trip signals of a travelling wave relay. Paper has made an attempt to obtain travelling waves components in the form of forward wave and backward waves from post fault components of voltage and current. These have been used for getting 0, α and β components using clarke's transformation which further reduces to df and dr respectively forming trip signals for tripping travelling wave relay. The proposed methodology is tested on a 500KV test system for different types of fault and different fault locations. Results obtained by proposed methodology are in total comparison to those obtained by corelation technique described in [1].