Synchronous reference frame phase locked loop in grid tied solar photovoltaic system

Abstract: The role of solar photovoltaic system in the production of electricity is steadily growing. A grid tied solar photovoltaic system is becoming more and more common because of the plentiful sunshine and advanced power technologies. The synchronization process or how to synchronize an inverter with the grid is a significant issue in the integration of a solar photovoltaic system and the grid. Using a proper synchronization method improves the power transfer between the inverter and the grid. The major factors that need to be measured and synced are frequency, phase and voltage magnitude. In this synchronization process, a Synchronous Reference Frame Phase Locked Loop (SRF PLL) is employed to identify the phase angle of the grid under normal and abnormal grid situations. Anti-islanding protection, a frequently demanded safety feature which will disconnects the inverter from the grid and limits the power flow from the inverter to loads when the grid enters a fault condition. It is important to ensure this protection when using a grid tied solar photovoltaic system, is presented in this paper.

Keywords: Synchronization, anti-islanding, SRF PLL, grid, solar.