Single order harmonic detection with incremental algorithm of DFT

To extract a single order harmonic component from single phase voltage or current is a difficult work by the existed instantaneous reactive power theory, which is dominant in the detection of the total harmonic components in three-phase system. A novel detection approach of single order harmonic in single-phase system based on discrete Fourier transformation with smooth moving window is discussed in this paper, and an incremental algorithm is presented to improve the dynamic response. Both simulation and experimental results show that the approach has the advantages of high accuracy and rapid response, and it can satisfy the requirement of active power filter for harmonic mitigation.