柔性多端交直流混联配电网的分层协同优化控制策略OA

Under the background of constructing the new power systems with high-proportion new energy and power-electronic devices,flexibility of the distribution networks becomes an inevitable trend.High efficient energy management is the crucial to fully develop the potential of the flexible interconnected distribution networks.Therefore,this paper presents a hierarchical coordinated optimization and control strategy for AC/DC hybrid distribution networks for the flexible multi-terminal interconnected devices,aiming to simultaneously enhance operational economy and safety.The proposed strategy consists of an intra-day centralized optimization layer and a local real-time control layer.At the upper layer,a unified modelling and optimized scheduling framework is developed,and inter-area power flows of the flexible interconnected devices are combined to realize the transfer of redundant power of new energy to high load areas,thereby significantly reducing network losses in the overall time.At the lower layer,the droop control of the converter is employed to realize fast voltage regulation by using the capability of power electronic devices in a short time.Furthermore,a droop parameter optimization model is formulated to minimize voltage deviation with explicit voltage stability constraints to effectively avoid voltage vibration due to improper parameters.Simulation results of case studies on a representative three-terminal AC/DC hybrid distribution system in Hengqin demonstrate that the proposed strategy can maintain dynamic stability as well as ensure operation economy and voltage safety,confirming its effectiveness and engineering applicability.