An improved technique for the estimation of local frequency, fundamental component phasor and instantaneous symmetrical components

Abstract

Fundamental component estimation, including its phase and amplitude information along with instantaneous fundamental symmetrical components, is of great importance for grid connected power electronics converters control, namely in power conditioning applications such as Dynamic Voltage Restorers (DVRs) and Unified Power Flow Controllers (UPFCs). Several methods have been proposed to estimate these parameters recently, particularly digital ones. The developments of new and more efficient microprocessor-based relays and supervising and monitoring systems have given support to those estimation methods. In this paper, an adaptive FIR filter based method for fundamental component estimation is used as support for a new proposed method. It enables fundamental component phasor, frequency and instantaneous fundamental symmetrical components estimation based on the grid voltage fundamental component. The method is tested under typical grid perturbations and is compared with two high performance alternative methods through objective and quantitative criteria.