Research on Smooth Transfer Control Strategy for Master-slave Microgrid

摘要

How to realize the smooth switching of microgrid between grid-connected mode(GTM) and islanding mode-(ILM) is a hot issue. For the ILM to GTM, this paper proposes a voltage and phase pre-synchronization link with frequency compensation, which solves the problem of frequency over-limit in the voltage pre-synchronization process and frequency jump at the moment of grid connection. For the GTM to ILM, the state follower is used to keep the input parameters of the inner loop unchanged, and on this basis, the d-axis reference phase follower is designed to satisfy the requirement that the d-axis reference angle remains unchanged at the switching moment, thus achieving a smooth transition. In order to verify the correctness of the theory, a master-slave microgrid simulation model was built on Matlab/Simulink, and the proposed control strategy was verified by simulation.