Exact Model Order ESPRIT Technique for Harmonics and Interharmonics Estimation

Harmonic, which is becoming more and more important day by day in the emerging power system, is one of the most critical power quality parameters. In this paper, the estimation of signal parameters via rotational invariance technique (ESPRIT)-based method is proposed with an accurate model order (the number of frequency components) estimate for power system harmonic and interharmonics detection. It is demonstrated that, even for high noise signal, the proposed algorithm is able to accurately estimate the number of frequency components present in the signal. The proposed method is capable of estimating the accurate values of frequency, amplitude, and phase angle of the distorted current or voltage signals for a wide range of sampling frequency and measurement noise. The robustness of the proposed method has been tested on several simulated synthetic signals and measured experimental signals for different nonlinear loads.