Improved Transverse Current Differential Protection Resistant to Power Swing

Abstract

Power swing phenomenon is a complex situation for relaying schemes protecting transmission system including double circuit transmission line. Transverse differential techniques based on superimposed current have limitation during power swing due to signal modulation. In this paper, an improved transverse differential protection using one cycle moving sum of superimposed current is proposed. The moving sum technique minimizes the residual value of the superimposed current present during power swing and provides significant index during faults. Proposed method is tested for a double circuit line for different fault conditions and compared with available technique.