A space-vector discrete Fourier transform for detecting harmonic sequence components of three-phase signals

In this paper, a discrete-time algorithm for separately detecting the positive- and negative-sequence harmonic space-vector components of a three-phase signal is presented. The discrete Fourier transform is applied to the three-phase signals represented by the Clarke's aß vector. The proposed transform outputs the instantaneous values of the fundamental frequency and harmonic component vectors of the input three-phase signals. A recursive algorithm for low-effort online implementation is also presented. The detection performance for variable frequency and inter-harmonic input signals is discussed. The proposed method performance is verified through experiments.