Power Allocation Strategy of Hybrid Energy Storage System Based on Supercapacitor SOC

In order to avoid the frequent overruns of supercapacitor in the process of smoothing power fluctuation of DC microgrid by hybrid energy storage and to extend its available time, a hybrid energy storage power allocation strategy based on fuzzy control is proposed. The method firstly divides five different working areas according to the SOC of supercapacitor, takes the SOC of supercapacitor as a variable, establishes the corresponding functional relationship with the filtering time constant in different working areas, and then corrects the filtering time constant based on the fuzzy control in order to realize the reasonable distribution of the power between the battery and the supercapacitor, and to ensure that the SOC of the supercapacitor is maintained within a reasonable range. The relevant model is built and simulated under MATLAB/Simulink, and the simulation results show that the control strategy proposed in the article can carry out reasonable power allocation according to the SOC of the supercapacitor while suppressing the power fluctuation, so that the SOC of the supercapacitor can recover on its own, preventing it from being over-charged and over-discharged, and improving the economy and stability of the operation of the DC microgrid system.