Research On Reactive Power Optimization Of Active Distribution Network Based On Hierarchically Coordinate Control Strategy

The large amount of access to distributed energy sources changes the management concept of traditional distribution network.Traditional management plans to arrange electricity production through load forecasting.While the rapid development of distributed energy,on the one hand brings the issue of intermittent and poor controllability,on the other hand,as a clean energy,distributed energy input can reduce power investment in the long-term,meanwhile it can improve the service quality of power users.In the background of active distribution network,the access of distributed energy brings new challenges and opportunities to the reactive power distribution and tage stability of distribution network.Therefore,it is practically necessary to study the reactive power optimization control of active distribution network under distributed energy access.This paper based on the development status of active distribution network,taking the reactive power characteristics of direct drive unit as the representative of distributed energy reactive power control,introduces the structure and operation principle of it,and the mechanical model and electromechanical model of the direct drive unit are set up.Based on the analysis of converter characteristics and control strategy of direct drive unit,the feasibility of direct drive unit on reactive power support capability of distribution network is demonstrated.The method of power flow calculation for distribution network with distributed energy is analyzed.Then reactive power optimization strategy of hierarchical coordinated control is proposed based on the reactive power optimization strategy of active distribution network,DMS reactive power centralized control and decentralized autonomous regional reactive power control of active distribution network reactive power optimization principle.In the DIgSILENT simulation platform,a model of active distribution network is constructed based on the simplified inverse distributed power supply.The reactive power optimization results show that the hierarchical coordinated control strategy is superior to the centralized control strategy and decentralized control strategy.