A DWT Based Differential Relaying STATCOM Integrated Wind Fed Transmission Line

Abstract

This paper presents the differential scheme of relaying protection of transmission line in a Static Synchronous Compensator (STATCOM) integrated wind fed single circuit line. The Discrete Wavelet Transform (DWT) and Discrete Fourier Transform (DFT) technique are applied for classification and detection of fault in STATCOM including wind farm. The STATCOM is positioned at central point of the transmission line and wind farm is connected at receiving end of the transmission line. The reactive power injection or absorption (i.e, shifting phase voltage with respect to bus voltage) depends upon the apparent impedance during the fault. The individual fault current signal (i.e, A, B and C) of three phase is extracted at both end of sending and receiving side of single circuit transmission line synchronously. It starts processing with the DWT and DFT to find the spectral energy content of each phase current signals at both end of transmission line. The Differential Spectral Energy(DSE) of current signals (i.e spectral energy of current measured at sending end minus spectral energy of current measured at receiving end) of each phase of transmission lines is used to register the fault pattern. This scheme is very accurate, effective and simple for fault classification and detection of transmission line.