The invention relates to a circuit structure applied to stabilize the output of a
microgrid energy storage system. The circuit comprises an
inductor L, a
capacitor C, a
resistor R, a photovoltaic panel PV, a
supercapacitor (UUC, RUC), a storage battery (Ub, Rb), four diodes (D1, D2, D3, and D4) and four switch tubes (M1, M2, M3, and M4). A circuit is connected in series and works in a
microgrid. When an
energy storage battery is in a charging state, the switch tubes M2 and M3
cut off, the switch tubes M1 and M4 are conducted, and a
photovoltaic power generation system and a
power grid charge the
energy storage system. When the energy storage battery is in a discharging state, the switch tubes M2 and M3 are conducted, the switch tubes M1 and M4
cut off, and the energy storage system discharges a load. Compared with a previous
microgrid energy storage system, by using the circuit structure of the invention, a response speed is fast, a photovoltaic battery output fluctuation caused by anenvironment change can be stabilized, and a
bus power sudden change caused by a load change can be restrained.