Research On Power Decoupling Method Of Microsources In Microgrid

In recent years, Microgrid has become a new hot topic in the field of energy research in the domestic and foreign electric power system. Compared with simple distributed generation, Microgrid can realize the new energy grid-connected applications in large-scale, also can improve power supply reliability and power quality as an effective complement to the main grid. At the same time, Microgrid can meet the demands of China’s new energy generation and sustainable development strategy and even provide the necessary foundation for the implementation of smart grid technology. This paper focuses on power decoupling method of microsources in Microgrid. Firstly, the background and meaning of the research is introduced. A systematic analysis on the production and development of distributed generation technology is given, so as to introduce the background, significance and the present research of Microgrid. And the Microgrid power electronic interface types are elaborated here. Secondly, according to the microsources based on inverter in Microgrid, such as micro-turbine, photovoltaic sources and power storage, mathematical model based on the state space is established, a decoupling control method of the inverter based on disturbance compensation and state feedback is proposed, design of the LC filter and double-loop control system of inverter for Microgrid is finished, which has laid the foundation on microsources power decoupling control in Microgrid. Thirdly, the power transmission coupling problem in Microgrid is studied under grid-connected operation. The relative gain on line power transmission coupling objects is also analyzed. A decoupling method is proposed based on the relative gain analysis and objective function diagonalization to implement the Microgrid line power decoupling control, furthermore, a method to select voltage reference in synchronous rotating coordinate is put forward. Finally, Considering the characteristics of the line parameters in Microgrid. microsources droop control method is further analyzed under Microgrid island operation in this paper. Then a reverse droop decoupling control method based on virtual frequency voltage is proposed to realize frequency and voltage regulation and ensure Microgrid frequency kept in the power quality allowable deviation range.