Harmonic/inter-harmonics detection using modified exact model order-based ESPRIT

Problems related to harmonics/interharmonics are growing rapidly in power system with the increasing use of power electronic devices. This paper focuses on estimating the harmonics/interharmonics using modified exact model order - estimation of signal parameters via rotational invariance technique (MEMO-ESPRIT). The modified exact model order (EMO) method is used to reduce the computational burden in detecting the harmonics/interharmonics components. Comparison has been made between EMO and MEMO to demonstrate the effectiveness of MEMO based method. Moreover, various parameter values like noise, size of autocorrelation matrix, etc. are varied to see their effects on the computational burden and accuracy of MEMO method. The performance of MEMO-ESPRIT algorithm is analysed with synthetic signals, single-phase PWM inverter and 250 kW grid-connected PV arrays using MATLAB/Simulink. The root-mean-square relative error has been obtained to validate the accuracy of the algorithm.