A novel control strategy for hybrid energy storage system to relieve battery stress

Energy storage system in wind power system is required to deal with the difference of power between generator side and load side. However, single storage element can not fulfill this goal ideally. Then, Hybrid energy storage system (HESS) is proposed that which combines two (or more) different kinds of storage elements has more superior performance than single storage element. In this paper, a topology of hybrid energy storage system which consists of a battery and a super capacitor is used. Besides, a corresponding control strategy is proposed, which use moving average filter (MAF) to substitute traditional low pass filter to distinguish the DC and AC component of the imbalance power and deliver the DC part to the battery and absorb the AC part to the super capacitor. It makes full use of the energy storage elements and the battery life is extended.