Restoration Of Distribution Network With Microgrid

Microgrid which effectively overcomes the disadvantages of direct connection of distributed generations and distribution network, is proposed as a radical solution to the current energy shortage and environment pollution by organic combination of local loads and distributed generations, which are usually high efficient, small scaled and environmental-friendly. Microgrid will definitely be widely connected into distribution network as a secure, reliable, economic, green and high efficient power supply mode in the future. Therefore, restoration of distribution network with microgrid is necessary to operation of the future distribution network.Firstly, features of distribution network and research significance of its restoration are briefly introduced. Then, the effects of microgrid access on distribution network restoration are systematically analysed and a three-level restoration strategy is proposed based on exploring the advantages of microgrid and the validity, rapidity, economy and reliability of restoration. Considering the variance of conditions, methods and results of these three strategies, different power flow models, objective functions and constraints are constructed separately. In addition, a genetic algorithm was introduced in the optimal power flow (OPF) of microgrid restoration and optimization of the second level strategy.The analysis of the service restoration problem of a distribution system with three feeders and eighteen nodes containing four microgirds after occurrence of single fault is given in the paper and feasibility of the microgrid restoration, validity of the new multi-objective optimizing model and practicality of applying genetic algorithm in the optimal power flow (OPF) of microgrid restoration and optimization of the second level strategy are verified.In the end the summarization of whole paper and the forecast of future works are presented.This work is supported by National Natural Science Foundation of China (No. 50837003).