Recursive estimation of power system harmonics

This paper presents the application of well known recursive estimation techniques to the important problem of power system harmonics in a noisy environment. on-line estimation of harmonic amplitudes and phases is performed using several variants of recursive least square (RLS) algorithms, known for their simplicity of computation and good convergence properties. The estimates are updated recursively as samples of the harmonic signals are received. A noisy harmonic signal from the AC bus of a six pulse rectifier is used as a test signal in the simulation. The various RLS algorithms are evaluated under different signal to noise ratios (SNR) and are shown to produce good harmonic magnitude and phase estimates even for a 0 dB SNR. Due to their simplicity, these algorithms are appropriate for on-line implementation in polluted power systems.