Research On Control Strategy Of Microgrid With Distributed Complementary Energy

Because of the obvious environmental and social benefits, the attention of distributed generation has been on the rise. Microgrid with distributed complementary energy (MDCE) can be satisfied with the various demands of user by integrating the advantages of distributed generations including wind power, solar power, fuel cells, combined cooling-heating-power system, storage device and so on. On the other hand, microgrid is a strong complement to power system and can operate not only in grid mode but also in island mode. For these reasons, microgrid has become a hot point of research around the world.The controls of distributed generation and grid-connected inverter in MDCE have been theoretically analyzed and simulated in this paper. According to a variety of distributed generations in microgrid, the theory of photovoltaic has been researched. And a control strategy has been proposed, named the MPPT and voltage control strategy of the three phases photovoltaic grid-connected generation, which can improve the quality of voltage at connect point. In the project of distributed power connects to microgrid, the grid-connected inverter is the key device. The theory and control technology of grid-connected inverter have been researched, and then a new type grid-connected inverter control strategy (V/f-P/Q control) in microgird is presented. In grid-connected mode, the distribution generation can output the setting active and reactive power. In islanded mode, the distribution generation can maintain the voltage and frequency stability of microgird. The simulation model, algorithm and control strategy have been built by PSCAD/EMTDC software in this paper. The simulation results demonstrated that the proposed control strategies were valid and correct.Finally, it elaborated some aspects of distributed generation demonstration system in HFUT. The simulation models, including generator system, solar power system, wind power system and control strategy, have been built by PSCAD/EMTDC software for research its dynamic characteristics.