Three State Kalman Filter based Directional Protection of Power Transformer

Due to interconnection, power system complexity is increasing day by day. So, reliable operation under fault conditions in power system is a major concern. As a heart of power system, transformer involves self importance with highest efficiency. Saturation of current transformer and magnetizing inrush are major issues for reliability of transformer protection. This paper presents detection of internal fault against external abnormalities on the basis of direction of primary and secondary current with respect to its voltages. Various fault and inrush case studies are generated on power transformer in PSCAD™ software. Three state Kalman filter is utilized to analyze current and voltage signals of primary and secondary side of power transformer. The algorithm is validated on MATLAB software after collecting data from PSCAD™ model. Various inrush, internal fault and external fault cases are authenticated using the projected scheme. It is observed that the proposed scheme effectively issue trip commands for all internal faults and remain inoperative for inrush and all external fault conditions.