Comparison of Modern Voltage Parameter Estimation Techniques under Various Voltage Conditions

Integration and control of the distributed energy resources (DER) specially wind generator and solar PV systems must require synchronization techniques. Phase-locked loops (PLLs) are widely used for monitoring, control and synchronization purposes. A PLL is a non-linear feedback control system that synchronizes its output phase as well as frequency with its input. In recent years, conventional and advanced PLLs are largely discussed by the researchers. In this paper comparison and analysis of different PLLs have been done under various grid-voltage conditions such as voltage sag, voltage swell, phase change and frequency change for the estimation of frequency and amplitude. The detailed simulation results have been presented for the clear understanding.