Research On Micro Grid Network Control And Simulation Platform

In today's world, with the rapid development of economy, energy demand is increasing day by day. However, the traditional mode of power generation not only consumes a lot of resources, such as coal, oil, natural gas, but also causes pollution to the environment. Distributed generation, as a new type of power generation, can make full use of the local clean and renewable energy, and become an effective means to develop green energy. However, due to the intermittent and instability of distributed power, directly access to conventional distribution network will impact on the power grid system. As a kind of autonomous system, micro grid can effectively manage the distributed power, so that the distributed power in the micro grid can smoothly access to the conventional distribution network, and ensure the safe and stable operation of the power grid system. Energy storage system as an important part of the micro grid, plays a role in buffering energy, and can according to the need to charge and discharge. It can improve power quality, then provide users with reliable electric energy. This paper focuses on the research of wind power generation system, hybrid energy storage system and DC system, including the models and control strategy. The details are as follows:Firstly, the mathematical model and control strategy of permanent magnet direct drive wind power generation system are studied. According to the control requirements of wind power generation system, generation-side uses speed outer loop and current inner loop control strategy, grid-side uses grid voltage orientation control strategy. In the MATLAB/Simulink software, build a wind power model. The simulation results verify the correctness of the control strategy.Then, studied characteristics of the storage battery model and super capacitor model, and their charge and discharge principle. Storage battery and super capacitor are complementary in performance, so the hybrid energy storage of storage battery and super capacitor is proposed. Choose this hybrid energy storage structure as the energy storage device of the DC micro grid system. By analyzing, the energy storage system can charging and discharging according to the demand.Furthermore, studied the structure and control strategy of bidirectional DC/DC converter. The structure uses half bridge bidirectional DC/DC converter, while the control uses voltage and current dual loop control strategy. Through MATLAB/Simulink simulation, the regulating energy bidirectional flow characteristic of bidirectional DC/DC converter is verified.Finally, the control strategy of AC/DC and the coordinated control strategy of micro grid are studied. In the MATLAB/Simulink simulation software, a DC micro grid system with wind power, hybrid energy storage and AC load is built. The simulation results show the effectiveness of the system control strategy, which provides a theoretical basis and simulation platform for the further study of the coordinated control strategy of micro grid system.