CONTROL OF GRID TIED INVERTER FOR HYBRID SYSTEM USING PLL

Abstract

In order to meet the requirements for grid interconnection, it is necessary that the control of Distributed Power Generation systems (DPGSs) should be improved. Therefore, grid synchronization algorithms play a vital role for Distributed Power Generation Systems (DPGSs). This paper discusses one of the synchronization strategies that use Phase Locked Loop (PLL) and its various types for synchronization of the grid - side converter. Different PLL implementation structures and their major characteristics are pointed out. The primary application of the proposed synchronization method is for the distributed generation units with renewable energy sources, which utilize power electronic converters as an integral part of their systems. The synchronization is usually carried out with respect to the voltage, frequency and phase angle of voltage (or current) signal(s) of the utility system.