Three zones adaptive characteristic of the mho distance relay by KU method

This paper presents the three zones adaptive characteristic of the mho distance relay for compensate of the phase to phase fault with fault resistance by KU method. Generally, the characteristic of mho distance relay is suitable for the phase fault protection and in the case of a low fault resistance. But, the fault in case of the phase to phase fault with fault resistance are a trajectory of impedance outside the protection zone of the R-X diagram and the circuit breaker does not trip. In this paper, we present an analysis of the three zones adaptive characteristic of R-X diagram of the mho distance relay for compensate of the phase to phase fault with fault resistance in the radial transmission line. The KU method has been shown an extent protection zone for the compensation of phase to phase fault with fault resistance. The algorithm of proposed system is verified by simulation and results.