A synchronization control method for micro-grid with droop control

Micro-grid should be able to operate in both islanding mode and grid-connected mode, but how to transfer smoothly between these two modes is a question. This paper presents a seamless transition strategy for droop-controlled inverters to operate in both islanding and grid-connected modes and transfer smoothly between these two modes. The control principle and pre-synchronization control strategy are introduced in detail, simulation and experimental results show that the micro-grid inverter can transfer smoothly between islanding mode and grid-connected mode.