Research on grid-connected/islanding smooth switching of micro-grid based on energy storage

The micro-grid is an approach to solve distributed generations interconnecting with power grid. Wind-PV-ES hybrid system could make full use of clean energy and have high reliability. Smooth switching between grid-connected and islanding mode is important to micro-grid stable operation. This paper proposes an improved control strategy combining master-slave control with peer-to-peer control in order to make transition between grid-connected and islanding mode smoother. A micro-grid model based on wind-PV-ES hybrid system is built with DigSILENT/PowerFactory, and the improved control strategy is realized on it. The result shows that this improved control strategy can ensure power balance, and keep connected bus voltage and micro-grid frequency stable during micro-grid mode switching.