A Superimposed Components based Fault Detector for Power System Applications

Primary and the most important task of a distance relay is fault detection. Inaccurate fault detection leads to unwanted tripping of transmission lines. A new robust technique for fault detection in a transmission line by a distance relay is presented in this paper. The method is based on superimposed component of phase current at the time of fault inception. The proposed method is tested upon the fault data obtained through EMTP/Matlab model. Fault detection by this new method is fast and accurate as compared to traditional techniques of fault detection. An adaptive scheme is given for frequencies variation in power system. The new technique is not affected by noises, frequency drift and other uncertainties. It is also able to detect high impedance fault as well as short circuit fault. Effectiveness of this method in present time is validated by the comparative assessments with conventional fault detection techniques.