A new method for phasor estimation in numerical protective relays based on generalized delayed signal cancelation filtering

This work presents a novel phasor estimation algorithm based on the Generalized Delayed Signal Cancelation (GDSC) method, for estimating phasors in numerical protective relays. The method implementation requires the space-vector concept, the Clarke (αβ0) transform, and by means of a discrete-time formulation and few arithmetic operations, predetermined undesirable sequence component harmonics are canceled, extracting the sequence fundamental-frequency or harmonic components, which are required for numerical protective devices algorithms. The proposed algorithm for phasor estimation is applied for implementing a distance relay. The proposed and traditional algorithms are compared by using recorded fault data of a real power system.