Dynamic Economic Dispatch Of AC-DC Hybrid Distribution Network Considering Multi-user Bidding

In recent years,a large number of photovoltaic,energy storage,personal computers,electric vehicles and other dc power supply and load appeared in the distribution network,which promoted the development of dc distribution network.As the main body of distribution network is still ac distribution network,dc distribution network will not exist alone,but in the form of ac-dc hybrid distribution network.There are various multi-users in ac-dc hybrid distribution network.Multi-users include a lot of flexible and controllable resources.It is of great significance to consider the participation of multi-users in economic dispatching and make full use of multi-users’ flexible and controllable resources to reduce the operation cost of ac-dc hybrid distribution network.Firstly,this paper studies the research status of ac-dc hybrid distribution network and economic dispatch of power system,and determines the research content.Then,considering the dc load in the dc distribution network,the optimal power flow model of ac-dc hybrid distribution network is established and solved by interior point method.Then,considering the specific characteristics of renewable generation users,energy storage users,flexible load users and household pv users among multi-users,the mathematical models of various users participating in the economic dispatching of distribution network are established.Energy storage can be divided into user-owned energy storage and power-grid company-owned energy storage according to different asset ownership.The energy storage users can participate in economic dispatching as power supply and power demand at different time periods.The dynamic economic dispatch model of ac-dc hybrid distribution network is proposed based on the lowest power purchase cost of power grid companies,and the power flow constraint and energy storage life loss cost are considered.The model is solved by interior point method.Then,the mathematical models of ac-dc doubly-fed load,interruptible load,shiftable load and transferable load are put forward,and the dynamic economic dispatching model is established considering the above loads.In this paper,the concept of partial surrogate cuts is introduced,and a partial surrogate cuts solution method for the dynamic economic scheduling model is proposed.The simulation results show that the power flow optimization of ac-dc hybrid distribution network by interior point method can reduce the total operating cost of distribution network.The dynamic economic dispatching model proposed in this paper can promote the interaction between multiple users and the distribution network,realize the flexible switching of ac-dc doubly-fed load,and realize the power complementarity between ac and dc distribution networks.The interaction between energy storage users and energy storage owned by power grid companies and distribution network can reduce the power purchase cost.In economic dispatching,the total power purchase cost can also be reduced by taking into account ac-dc doubly-fed load,interruptible load,shiftable load and transferable load.