Optimal Dispatch Research Of The DC Distribution Network Including Distributed Energy Resources

With the development of society and economy, demand and quality of electric energy increase fast. And the traditional AC distribution network is facing many problems, such as the scarcity of power-line corridor, the insufficient of power quality, the bad control performance and the bad compatibility to the distributed energy resources(DER). But the DC distribution network has the advantages of lower cost, lower energy loss, flexible operating modes, high efficiency and high power quality, which can solve the problems of AC distribution network well. On the other hand, the distributed usage of energy has become a important part of smart distribution grid's development. The DERs have the advantages of high efficiency, environmentally-friendly, high reliability and good economic benefit. DC distribution network has good compatibility with DERs, so it will become a important development direction. This paper studies the optimal dispatch problem of the DC distribution network with DERs and the main research work is as follows:1. Combine with the current situation of AC distribution network, this paper design a structure of DC distribution work with the idea of subarea division, which can play a good effect of DC line. Then this paper designs the configuration principle and operation straregy of DERs. After that, this paper designs the energy management scheme for the distribution network, wihch contains the fundamental of energy management, the setting strategy of DC subarea's slack bus and the selection strategy of VSCs.2. Study the optimal dispatch method for the designed DC distribution network. Based on the dispatch resources with different power response characteristics, this paper designs a multi-time scale optimal dispatch strategy, and introduces the effects of different time scale. Then it builds the decision mathematical model with the optimization objective of minimizing the dispatch cost, and solves the optimization model by the decomposition-coordination parallel optimization algorithm.3. This paper constructs the example system and calculates the dispatch schemes for it in different situations with the dispatch method proposed above. By comparing and analyzing the calculating results, the good effect of the designed structure and the effectiveness of the energy management scheme and optimal dispatch method proposed can be verified.