Performance evaluation of harmonics detection methods applied to harmonics compensation in presence of common power quality problems

Harmonics estimation methods are analyzed in presence of different power quality problems, namely voltage sags, voltage unbalance, voltage distortion and variations of power supply frequency. The harmonics detection algorithms are based on the instantaneous reactive power (IRP) theory, the discrete Fourier transform (DFT), the recursive discrete Fourier transform (RDFT) and the Kalman filtering (KF) approach. Simulation results obtained with Matlab/Simulink/Power System Blockset are presented to compare their performance in term of precision and transient response and for harmonics compensation by a active power filter.