Coordinated Optimal Control Method Of Active Distribution Network Based On Power Supply And Storage Capacity Index

Environmental problem and energy crisis are two big challenges of modern society.To cope with them,more and more distributed generations(DGs)are being integrated into distribution network.DGs have some good features,such as environmental friendliness,flexibility,fast investment,et al.Distribution network directly link customers with power grid and support electricity to the users.Integration of various DG devices have changed the configuration of distribution network and brought new challeges to its operation and control.And,the traditional distribution network are now changing into an active one.In this thesis,coordinated control strategies of active distribution network(ADN)are deeply studied and discussed.Main works are as follows.(1)Characteristics of different controllable units in the ADN are investigated.And,ADN system is separated into several control areas.A hierarchical management mode is then put forward to coordinate various control units in different areas.Sensitivity technique is used to evaluate the power response capability in each control area.An optimization model is proposed to achive the optimal control strategy with high efficiency.(2)Influence of different DGs in ADN is investigated.Suitable models of the control units are derived.Then,a multiple optimization model is proposed to coordinate the objectives of security and economy.The quality of the power supply in the system is improved with the given method.(3)Reactive power capability of the voltage source converter station is studied.A central plus local control mode is designed to coordinate various AC/DC reactive power sources in ADN system.And,a voltage control strategy is proposed to coordinate the normal operation,preventive control and emergency control.The voltage fluctuation in ADN system is significantly smoothed and the system reliability is greatly enhanced.