Research on Off-grid Control Strategy of Micro-grid Based on Current Compensation

Micro-grid can operate in both the grid-connected mode and stand-alone mode. Seamless transfer is required in micro-grid switching progress based on IEEE1547.4. The key technology is to reduce the impact of current and voltage to load or grid during the mode transfer. A practical grid-connected switch is a physical switch and the switching delay exists. The paper analyzes the influence of the switching delay in detail, that is, there is a uncontrollable intermediate state in the transfer process of off-grid, which will cause voltage and current overshoot. This paper presents a current compensation control strategies without increasing system complexity. Detailed analysis of the parameters affect on the system and the design basis are obtained. Simulation and experiment results verify the correctness and feasibility of the proposed method.