For the purpose of avoiding deep charging and discharging of the battery in islanded DC microgrid so as to prolong its service life

and based on full consideration of the battery’s state of charge（SOC）

a multi-source coordinated control strategy including primary decentralized control and secondary centralized control for islanded DC microgrid is proposed.Primary decentralized control is used to realize autonomous coordinated operation of micro-sources considering battery’s SOC.Under primary control

DC-bus voltage changes with SOC according to the segmented droop characteristics and when SOC is close to the limits

DC-bus voltage will rise or fall

which leads to new energy power generation curtailment or load shedding.In order to satisfy the strict requirements of DC-bus voltage under specified conditions

the droop curve of primary control is adjusted by secondary centralized control

which is used to eliminate the stable voltage deviation produced by primary control when SOC is close to the upper limit.Finally

an experimental hardware-in-the-loop simulation（HILS） system of wind-battery based islanded DC microgird is constructed.The experimental results show that the proposed multi-source coordinated control strategy can effectively avoid the battery’s deep charging and discharging

and the quality of DC-bus voltage is modified.