Frequency deviation control of isolated PV-diesel in micro-grid using disturbance observer

A novel frequency coordination control method is proposed for a PV-diesel hybrid isolated microgrid. In the proposed coordination control strategy, the photovoltaic system (PV) are adjusted by output power command based on the estimated load value to reduce the frequency deviation. Considering the load is also variable in the microgrid, the disturbance observer(DOB) is designed to estimate the variable load. In the simulation results, the proposed frequency control method can reduce the frequency deviation induced by the load changes and the hybrid renewable energy fluctuation. This method can reduce the energy storage device hardware investment in the process of large-scale microgrid construction.