Low effort digital filters for fast sequence components separation of unbalanced and distorted three-phase signals

In this paper, two methods for determining fundamental-frequency and harmonic positive- and negative-sequence components of three-phase signals are investigated. Many aspects of the space vector discrete Fourier transform and generalized delayed signal cancelation such as computational burden and response time for different possible implementations, frequency adaptation schemes, stability of recursive implementation and rounding error effects are discussed. Simulations and experiments are presented in order to verify the performances and illustrate the theoretical conclusions.