Research on hybrid energy storage capacity configuration based on double-layer cluster division

The integration of high proportion renewable energy aggravates the net load fluctuation and affects the safe and stable operation of the distribution network. In this paper, a distributed hybrid energy storage capacity optimization configuration method based on double-layer cluster division is proposed to suppress closest net load fluctuation. Firstly, cluster division based on the integrated active/reactive-voltage sensitivity is performed to initially determine the hybrid energy storage action region. According to the result of partition, the power flow propagation index is constructed by combining the power flow tracing algorithm and the topology of the distribution network. Secondly, by setting the power flow propagation index threshold to divide sub-clusters, the access location and action region of hybrid energy storage are determined. Then, based on different power flow propagation index thresholds, the net load of the sub-cluster is decomposed using variational modal decomposition (VMD) to determine the reference power of energy-type and power-type energy storage. The NSGA-II algorithm is used to solve the hybrid energy storage capacity optimization configuration model with the rated capacity of energy storage as the optimization variables. Finally, corresponding to different power flow propagation index thresholds, the optimal configuration scheme is determined by ranking the annual comprehensive configuration cost of hybrid energy storage and the tie line power of bordering clusters. Test carried out on the IEEE 33-node distribution network system have verified the effectiveness and feasibility of the proposed method.