Comparison of Two Fault Classification Schemes in Non-effectively grounded distribution system and Their Combination

In this paper, a combined fault classification scheme is proposed after comparison of two separate schemes, which are called T-based and S-based scheme respectively. The principles of T-based and S-based scheme are introduced firstly. Secondly, each performance under different signal noise ratios is studied through simulation. Through comparison of the performances, a combined scheme which has better anti-noise ability is proposed. The proposed scheme reasonably utilizes both stationary component and transient component induced by fault and, can accurately classify ten short circuit fault types in non-effectively distribution system. The adaptability under topology change of network is studied through simulation in PSCAD/EMTDC environment. The results show that the combined scheme has good adaptability.