Frequency control of islanded microgrid based on wind-PV-diesel-battery hybrid energy sources

Frequency control is a big challenge to an islanded microgrid, resulting from load and those intermittent microsources such as solar photovoltaic (PV) and wind turbine (WT). A novel frequency control scheme is proposed to enhances the anti frequency interference ability for islanded microgrid. The hierarchical frequency control structure is designed according to different net load fluctuation range and control characteristics of battery storage system (BS) and diesel generator (DE). The primary frequency regulation of battery inverter is based on droop control strategy to improve the transient frequency response, and a frequency error integral regulation method of diesel generator is adopted for secondary frequency regulation to regain a new steady frequency state. Finally, simulation studies prove the effectiveness of the proposed frequency control method.