Improved Symmetrical Fault Detection Scheme during Power Swing

Relays may not perform as intended occasionally due to many complex reasons, which may result in relay misoperation. This paper provides a fast detection scheme for symmetrical fault during power swing based on travelling wave theory and wavelet transform. The implementation of the proposed method is discussed in detail, which covers implementation framework, data requirements, selection of mother wavelet, and fault detection criteria. The simulation cases are studied by using IEEE reference model implemented using Alternative Transient Program (ATP) and the test results are presented in this paper. This proposed method can be used for distance relay operation blocking or monitoring.