Islanded and Grid-Connected Control in a Microgrid with Wind-PV Hybrid

摘要

Microgrid (MG) operation and use of renewable energy sources(RESs) in power systems has received a lot of attention in the recent past as grids evolve towards smart grid operation. This is because they can operate either in grid-connected or islanded mode and ensure critical loads are supplied with power without interruption in case of a contingency. However, this concept comes with its associated challenges like timely and accurate islanding detection and proper control of voltages and frequency within islanded MG. This paper designs and analyzes a control scheme for an islanding operation of a MG supplied by RESs that can operate in grid connected mode and Islanded mode. The RESs controller system will detect an islanding situation and switch to a voltage control mode when the MG is cut off from the main grid. In grid connected mode, the interface control is designed to provide constant active and reactive power to the grid. When the grid is disconnected, an islanding detection algorithm will transfer the inverter into voltage control mode after proper resynchronization without affecting the critical loads. The performances of presented controller have been simulated and verified in the MATLAB/Simulink platform.