Performance Analysis of Adaptive Filters based on Robust Second Order Generalized Integrator under Adverse Grid Condition

Abstract

With increase in penetration of the distributed power generation systems into the grid, the grid voltage becomes highly distorted and unbalanced. In this situation designing a phase lock loop (PLL) is a challenge to estimate the phase, frequency and amplitude of the utility voltage. This paper presents a filtering technique based on adaptive filter called second order generalized integrator (SOGI). Under transient fault condition when the three phase grid signal is highly polluted with harmonics and sudden frequency change or voltage dip occurs, it is a critical task to extract the fundamental component of the grid signal. In this paper, for extraction of the fundamental component from the polluted grid signal, two adaptive filters using SOGI are implemented in the stationary reference frame. To analyse the disturbance rejection capability of the SOGI filter different short period disturbances has been introduced in the three phase grid signal and the robustness is evaluated on the basis of its transient response and harmonic analysis. The simulation result validates the excellent performance of the filter.