Harmonic Analysis Using Adaptive Filter Algorithm

-This paper presents a software filter for fast estimation of harmonic and frequency components of a power system voltage or current signal corrupted by noise with low signal to noise ratio (SNR). This new algorithm is based on an objective function often used in independent component analysis for robust tracking under impulse noise conditions. Instead of choosing the step size η and the parameter β of the cost function by trial and error, an adaptive particle swarm optimization technique is used alternatively to obtain both η and β to reduce the error between the observed voltage or current samples and the estimated ones. Using the optimized values, the amplitude and phase of the fundamental and harmonic components are estimated. To test the effectiveness of the algorithm, several time-varying power system signals are simulated with harmonics, inter-harmonics and decaying dc components buried in noise with low SNR and are used to estimate the frequency and harmonic components. The results so obtained is found satisfactory and given to prove the validity of the proposed algorithm.