Research On Construction Of Active Distribution System And Its Control Scheduling Mechanism

With the reform of electrical energy,the generation and consumption of renewable energy have become an important research topic in power system.The construction of UHV power grid provides a good solution to the large-scale centralized consumption of renewable energy,but the consumption way of distributed renewable energy in the distribution network is still a problem to be solved at present.The intermittence of distributed power generation brings many problems to the stable operation of distribution network.Traditional grid can't effectively achieve the consumption of distributed generator of high permeability through active control of grid resources.Meantime,under the background of power market reform,the diversification of ownership of all kinds of resources of distribution network increases the difficulty of unified dispatching of distribution network.The concept of active distribution system is proposed to solve the consumption of intermittent distributed generator and the coordinated scheduling of various types resources of distribution network.Active distribution system is an important part of the construction of intelligent distribution network,the core of it is to achieve the consumption of renewable generation and the safety and economy of distribution network operation through the coordination regulation and control of various types of resources,while reducing the costs of users and improve the benefits of participants.Firstly,this paper divides the internal resources of active distribution system according to the ownership of the assets,proposes the concept of virtual micro-grid and analyzes the multi-interest factors in the active distribution system,and then analyzes the structure of active distribution system from the view of energy flow,information flow and capital flow.The control scheduling mechanism of active distribution system with load,transmission network,distributed generator of network,virtual micro-grid and charging station are established.The scheduling model of the internal resources of active distribution system is set up,including virtual micro-grid scheduling model,the scheduling model of the charging station and the load adjustment model under the real-time electricity price.Aiming at the shortcomings of single intelligent optimization algorithm,this paper proposes a cell membrane-improved particle swarm optimization based on the idea of parallel hybrid intelligent algorithm.Then the two-layer joint optimal dispatching model of active distribution system is established,the lower layer performs the independent optimization of the independent interests,and the coordination layer is to coordinate the exchanged power between the virtual micro-grid and the active distribution system.Finally,an improved IEEE 14-node active distribution system is used as an test example.On the basis of load adjustment,three optimization methods are proposed: independent of virtual micro-grid,independent optimization of distribution network and joint optimization of active distribution system.From the whole scheduling cycle and single-time,comparing the three optimization methods.The results of the comparison of three optimization methods show that the joint optimal scheduling model is effective to reduce the running cost of the virtual micro-grid and improve the operation quality of the network.