An optimal planning method is proposed for power distribution system with energy storage systems (ESS) in this paper, in which the degradation and ancillary service revenue on frequency regulation of ESS are both considered, as well as the network configuration, siting and sizing for ESS and substation expansion. The problem is formulated as a mixed integer programming (MIP) one to optimize the overall planning cost, including investment and operation cost, power transaction cost, revenue from regulation services and degradation of ESS. In addition, the model co-optimizes charging/discharging of ESS to earn money from regulation services and prolong ESS’s lifetime simultaneously by adding a penalty term in the objectives, thus further benefiting the economy of the distribution system. A planning problem based on IEEE 33-bus system is tested to demonstrate the effectiveness of the proposed method.
Keywords frequency regulation, network configuration, energy storage system (ESS), mixed integer programming (MIP), degradation penalty