Power Coordination Control of Hybrid AC/DC Microgrid Based on Battery’s State of Charge

Photovoltaic (PV) has the characteristics of strong intermittent and random output, and is often equipped with energy storage to suppress the fluctuation of power. In this paper, a coordinated control strategy of hybrid AC/DC microgrid based on the state of charge (SOC) and system operation mode is proposed. When in grid-connected mode, the stability of the DC bus is maintained according to SOC of the battery by coordinating the battery and the interlinked converter (ILC); when in islanded mode, the differential of SOC is used to adjust the output power of PV to respond jointly power fluctuations suppress sudden changes in energy storage power and enhance system reliability. Besides, the ILC control strategy is switched according to the state of charge of batteries in AC and DC side to maintain the system stability. Besides, the only way is to reduce the active power generated or cut off some secondary loads in order to keep system stable when the batteries quit one after another. Finally, simulation tests are conducted to verify effectiveness of the proposed strategy.