Dynamic Reconfiguration Of Hybrid AC/DC Microgrid Research

Renewable and clean energy becomes important way to deal with the dual crisis of both the environment and energy. While hybrid AC/DC microgrid is a distribution subnet which has distributed generation (DG) of renewable and clean energy, energy storage device and local loads, assigning the DGs to the different reasonable buses along with their output characteristics. It can realize maximum use of renewable energy and so it obtaines the widespread attention in recent years. However the existing hybrid AC/DC microgrid architecture rarely changes during operation, while the output power of DGs is random and intermittent, furthermore, loads of microgrid fluctuate wildly, which leads to the microgrid system is difficult to obtain the optimal state. In order to solve the problem, dynamic reconfiguration of hybrid AC/DC microgrid is established automatically according to environment, which is an important method to optimal operation of hybrid AC/DC microgrid.This paper mainly studies the dynamic reconfiguration of hybrid AC/DC microgrid. The main work is as follows:Firstly, this paper reviews the research situation of the microgrid reconstruction, and then introduces several common topologies of hybrid AC/DC microgrid and the control method of DGs and coordinated control strategy of hybrid AC/DC microgrid. On the basis, a topology of hybrid AC/DC microgrid is proposed.Secondly, very short-term load forecasting model and photovoltaic power prediction model is established based on Support Vector Machine (SVM). Firstly, the common methods of forecasting are introduced. And then historical data is preprocessed, forecasting samples are achieved by correlation coefficient method. Finally the prediction model is achieved.Again, the optimized model of dynamic reconfiguration of hybrid AC/DC microgrid that proposed in this paper is established. And the topology of hybrid microgrid is dynamically optimized through the NSGA-II.This thesis also establishes the simulation model of hybrid AC/DC microgrid used to dynamic reconfiguration in Matlab/Simulink. The coordinated control strategy of hybrid AC/DC microgrid is determined for both grid-connected mode and isolated mode. The DGs model and control method of their converter is designed. The optimal operation of hybrid AC/DC microgrid is realized. Finally the feasibility and effectiveness of the proposed dynamic reconfiguration based on NSGA-Ⅱ is verified on the platform.