Distributed primary frequency regulation of grid-connected photovoltaic power station with battery storage

Large-scale renewable energy connects with power system has posed great challenges to the safe and stable operation of power system, in order to solve the problem of frequency stability caused by large-scale photovoltaic connects with grid, a method of distributed frequency regulation by meanings of distributed battery energy storage system (DBESS) in grid-connected photovoltaic power station is proposed. By the way of paralleling a small capacity battery pack into the inverter DC side, fast active support is provided by battery pack when the system frequency is disturbed. Meanwhile, the inverter can adaptively determine the inverter permanent speed droop of itself according to the state of charge (SOC) of the battery pack during primary frequency regulation, to meet the system needs in different situations. Simulation result shows that the distributed frequency regulation proposed in this paper increases rapidity, accuracy and controllability of active control in the photovoltaic power station when system frequency disturbs, and it can meet the demand of the power system primary frequency regulation.