Single-Phase Multiple Delayed Signal Cancellation Filter-Based Enhanced Phase-Locked Loop for Accurate Estimations of Grid Voltage Information

Abstract

Single-phase grid voltage information such as phase-angle, frequency, and amplitude are crucial for synchronization and control of grid connected power electronic converters. In this paper, a new single-phase filtering technique based on multiple delayed signal cancellation (MDSC) is proposed to extract both in-phase and quadrature components of the selected harmonic component of the grid voltage signal. This MDSC technique provides the flexibility to configure the undesired harmonics and hence the delay time introduced by the operator can be reduced in comparison with existing techniques. The proposed MDSC filter can be applied to the enhanced PLL (EPLL) for accurate estimations of grid voltage information. To validate the effectiveness of the proposed method, experiments are conducted for comparing studies of the proposed MDSC-EPLL with the EPLL and the cascaded delayed signal cancellation (CDSC)-EPLL under various grid voltage disturbances.