Research On The Control Strategy Of Microgrid Inverter

As the traditional energy sources are facing serious energy crisis and environmental pollution, the distributed generation technology based on solar energy, wind energy and so on is becoming more and more attractive; however, the multiple units access of distributed generation brought great negative impact on the grid, so microgrid control technology emerge as the times require. Microgrid, connected inverter and load, which is a micro grid that is a controllable power system, and can operate in both islanding mode and grid-connecting, is becoming current research emphasis, and represents a new developing trend.This paper mainly studies the control strategy of microgrid inverter, referencing the control strategy of synchronous generator to control the inverter, the main contents of this paper are as follows:(1) The background, concept and development of microgrid were briefly described.(2) The current inverter control strategy are analyzed. Some controlling strategy, such as microgrid droop-control, PQ control and V/f control, are introduced respectively, and pointed out that the microgrid inverter in different running modes should be used different control strategy. According to the analysis of characteristic of synchronous generator, virtual synchronous generator control strategy is given.(3) Introduce the mathematical model of virtual synchronous generator, and give the realization of virtual synchronous generator algorithm according to the mathematical model of virtual synchronous generator, and take an depth study of the effect of the equivalent output impedance(4) Reference the basic principles of governor and excitation controller of synchronous generator in traditional power system, the power frequency controller and voltage controller of virtual synchronous generator are designed.(5) Simulation for virtual synchronous generator in independent operation using MATLAB/Simulink are given. The results of the simulation verify the virtual synchronous generator algorithm and control strategy.