微电网中混合储能系统的小波包-模糊控制策略

Wavelet Packet-Fuzzy Control Strategy for Hybrid Energy Storage System in Microgrid

为了充分发挥混合储能系统(hybrid energy storage system,HESS)在微电网中的应用优势,提高微电网运行的经济性和可靠性,提出了HESS的小波包-模糊控制策略。在平抑可再生能源输出功率波动的基础上,分别考虑并网时功率交换的实时电价和孤岛运行时的缺电量,建立起并网经济性评价指标和孤岛负荷缺电指标。对间歇性微电源进行小波包分解以获得HESS的初始充放电指令,由超级电容器承担网内瞬时功率波动的平抑任务,以网内不平衡功率对蓄电池充放电指令进行修正,再通过模糊控制获得蓄电池充放电的最终指令。最后,以风光燃储微电网为例验证了所提控制策略的有效性。

To make full use of the advantages of hybrid energy storage system （ HESS）, and improve the economic and reliability of microgrid operation, this paper proposes the HESS wavelet packet-fuzzy control strategy. Considering the real- time price of exchange power under grid connected operation and the lack of electricity under island operation, the grid economic evaluation index for grid connected operation and the loss of power supply probability for island operation are established based on smoothing the output power fluctuations of renewable energy. We obtain the initial charging and discharging instructions of HESS through the wavelet packet decomposition of intermittent micro power supply, use super capacitors to stabilize instantaneous power fluctuations, apply the unbalanced power to modify the instructions of storage battery charging and discharging, and then obtain the final instructions of storage battery charging and discharging through fuzzy control. Finally, the efficiency of the proposed control strategy is demonstrated by a ＇Wind-PV-Coal-Energy Storage microgrid.