Six phase transmission line protection against open conductor, phase to ground and simultaneous faults using fuzzy inference system

Abstract

Conventional techniques fail to handle classification and location of simultaneous phase to ground and open conductor faults. In this regard, a novel classification and location strategy based on fuzzy logic is proposed in this paper. The main contribution of fuzzy strategy is to improve six phase transmission line (SPTL) under phase to ground and open conductor fault protection schemes. Moreover, fuzzy strategy identifies and locates simultaneous occurrence of open conductor and phase to ground faults. MATLAB software is used to simulate the SPTL. The measured instantaneous values of current in each phase at one end of SPTL are processed by low pass Butterworth filter, sampler and discrete Fourier transform. The obtained fundamental component of currents is selected as input to the proposed classification and location strategy. An advanced soft computing toolbox i.e., fuzzy toolbox, is used to implement fuzzy inference systems. From the simulation test results, the fuzzy strategies not only classify faults correctly, but also predict the location of faults precisely. The effectiveness and feasibility of fuzzy strategy is validated by the obtained test results considering the effect of variation in different fault parameters such as fault type, fault resistance, fault location and fault inception angle.