Fault direction estimation in radial distribution system using phase-change in sequencecurrent

Summary form only given. This paper presents a method for estimating the direction of fault in such radial distribution systems using phase-change in current. The difference in phase angle between the positive sequence component of current during fault and prefault conditions has been found to be a good indicator of the fault direction in a three phase system. A rule base formed for the purpose decides the location of fault with respect to the relay in a distribution system. Such a strategy reduces the cost of voltage sensor and/or connection for a protection scheme which is of relevance in emerging distributed generation (DG) systems. The algorithm has been tested through simulation for different radial distribution systems.