A novel control strategy of inverter in distributed generation with seamless transfer capability

In order to improve power reliability of critical load, distributed generation (DG) should be with intentional islanding operation when utility is outage. This paper proposes a novel control strategy for three phase inverter in DG to realize transferring between grid-tied and islanding modes, which is with an inner inductor current loop and outer capacitor voltage loop in the synchronous rotating framework (SRF). When islanding happens, the drift of amplitude and frequency in load voltage can be restricted in the given range allowed by the utility. Finally, the proposed control strategy is verified by simulation and experimental results.