电池储能系统辅助的离网型风能转换系统在恶劣电池荷电状态条件下的运行

Wind Energy Conversion systems (WECS), supplying islanded microgrids, often incorporate a Battery Energy Storage System (BESS) as an energy-buffer. To ensure safety and long life, the battery-bank (BB) in such systems must not be overcharged or deep-discharged. This paper proposes a reconfigurable operational strategy for a doubly-fed induction generator (DFIG) based islanded WECS integrated with a BESS. When the State-of-Charge (SoC) of the BB approaches the maximum limit, the rotor side converter regulates the DC bus voltage using a modified voltage controller while operating the DFIG away from the Maximum Power Point. When the BB-SoC approaches the minimum limit, a minimum consumer-discomfort factor based load-shedding strategy is proposed so that the BESS can regulate the DC-bus voltage without deep discharging the BB. The DFIG-BESS system supplying the benchmark CIGRE residential distribution network has been simulated in an Opal-RT real-time simulation environment. The proposed voltage controller shows 69.44% and 46.66% lower undershoot in the DFIG-stator active-power and 3.45% and 99.83% lower DC-voltage deviation compared to a PI-controller and latest literature, respectively, while transiting from the BESS to RSC based DC-bus voltage regulation. The proposed load-shedding strategy also reduces the DC-bus voltage dip significantly compared to a similar strategy proposed in the literature.