Research On Cooperative Operation Control Strategy For Active Distribution Network

In recent years,energy crisis attracts great attention in worldwide.The cooperative control of active distribution network(ADN)systems with multiple distributed generations paralleled is one of the research hotspots in renewable energy technology field.Active distribution network is considered as the advanced stage technology of smart grid,which control networking of information flow is a development trend of smart grid.The cooperative operate control among source-load and distributed generator and energy storage of system level are the key to the stable operation of active distribution network system.This thesis focuses on the coordinated operation of the source-load and distributed and energy storage system in active distributed network.The main research works are as follows:1)Based on the distributed hierarchical control theory,the architecture of distributed/decentralized hierarchical coordination control is established for active distribution network.The primary control layer is combined with the secondary control layer of the architecture,which adopts Mixed layer-divided control method.The establishment of the control architecture provides a theoretical basis for subsequent research.2)Considering the problem of coordination operation of intermittent renewable generations(photovoltaic and wind power)and flexible load in active distribution network,a distributed coordination optimization control strategy based on dynamic consensus algorithm is proposed.Distributed secondary controllers of distributed generators are connected by the distributed sparse network through distributed secondary control method.As an agent node of networked system,it interchanges information with its neighbors.The dynamic consensus algorithm is used to obtained equal incremental cost of distributed generator power of the grid which would effectively reduce systems generating cost.Besides,cooperative optimization operation of source-loads and maximization of economic benefits is realized.Finally,the simulation analysis results of IEEE14-bus distribution test system is carried out to verify the effectiveness and feasibility of the proposed method.3)Considering the problem of the discharge rate of energy storage systems in case of power-shortage and load fluctuations in active distribution network,balancing the discharge rate of energy storage systems control strategy based on dynamic consensus algorithm is proposed.It interchanges information of energy storage systems state-of-charge(So C)with its neighbors through distributed hierarchical control.The dynamic consensus algorithm is used to obtained equal state-of-charge of energy storage systems of the grid.The output power sharing of the distributed generator and the balancing discharge rate of the energy storage systems is realized by regulating the virtual resistance.The simulation platform is built based on Matlab/Simulink software.The validity and feasibility of the proposed method has been further verified by simulation results.