Study On Coordinated Control And Load Terminal Management For Active Distribution Systems

The grid-connection of renewable resource and distributed resource is the future development of Electrical Power&Energy Systems. However, the large-scale integration of fluctuant energy, the introduction of high-permeable distributed generation and the complicated trend of load characteristic all contribute to the difficulty of safety and steady operation of power system. Due to the technical defects of the traditional distribution system, Distributed Energy Generators are hard to connect with grid directly, which lead to the expansion of energy gap and the losing of wind farm. Hence, it is necessary for us to enhance the admitting ability of Distributed Energy Generators, and promote the transform from the traditional distribution network to a new type of distribution system, which can actively control the load and power flow.Active distribution system is a new distribution system, since it meets the developing trend of the active control and management, Distributed Energy Generators can be widely introduced into the distribution systems, flexible load and energy storage advices are emphasized, the key technology of intelligent power distribution can be realized. In this paper, the concept of Active Distribution System is discussed firstly. And the domestic and foreign research present situation of the topic is introduced in detail. Comparing with the microgrid technology, the advantages of active distribution system, which is the advanced stage of smart grid, are highlighted. Secondly, based on the analyzing of the key component and the key techniques of Active Distribution System, research of the approach and application prospect is done, the concept and modules of ADS is proposed. Thirdly, the coordinated operation multi-agent module of Active Distribution System is presented in this paper. This module consist of top ADS control center agent, regional ADS agent, and the agent unit of bottom system. The targets of distributed self-management and global optimization are achieved. The coordination scheduling objective function under multiple constraints is established and the feasibility of the proposed scheme is verified. Finally, the characteristics of interruptible load in Active Distribution System are analyzed. Based on the intelligent metering technique and communication technology, the control strategy for load is studied. And then, the control modules of flexible load is established and simulated. For solving the problem of power quality deterioration, the online technology of power quality for load terminal is analyzed which is then proven by the simulation.The coordination dispatching pattern and control technology of load terminal proposed in this paper can improve the access rate of distributed resource while the power distribution reliability is guaranteed and providing technological support for building stable, safe, reliable, and high-performance smart grid.