Deadbeat control with power sharing for supercapacitor/ battery-based hybrid energy storage systems in DC microgrids

摘要

Hybrid energy storage systems (HESS) have been widely implemented in DC microgrids to balance power flow between renewable energy sources (RESs) and load. In this paper, a deadbeat control with power sharing for HESS consisting of battery and supercapacitor (SC) in DC microgrids is proposed. In the presented control strategy, the optimal duty ratio can be generated in a single sampling period based on current and voltage values at present. Therefore, the DC bus voltage can be stable under different operation modes. Meantime, the battery responds to average power demand, and the SC deals with transient power fluctuations, smoothing the battery current to extend cycle life and improving the HESS dynamic response effectively. Compared with the conventional proportional-integral (PI) based control strategies, the proposal has several advantages including faster DC bus voltage recovery, less voltage oscillation, and no need for PI parameters. A simplified DC microgrid model is established in Matlab/ Simulink which verifies the effectiveness and superiority of the proposed method with short-term and long-term simulations.