Research On Micro-Gird Inverter Control Strategy Based On VSG

Distributed generation technology has great potential for scientific research and application, but its strong randomness and large volatility affects the development and utilization. Micro-grid is an effective way of comprehensive utilization of distributed power supply, and it has become a research hotspot.This paper analyzes the research background of micro-grid and distributed generation, introduces the research status at home and abroad, and introduces the related basic concepts.Analysis of micro-grid inverter commonly used three kinds of control mode:PQ control, V-f control and Droop control, summarizes the characteristics and application range of different control ways. Analysis the advantages of virtual synchronous generator (VSG) control strategy.The bottom layer control of the virtual synchronous generator is introduced, including the phase locked loop, coordinate transformation theory, LCL filter circuit and micro-grid energy storage technology. Phase locked loop is an important component of micro-grid, which is used to obtain the phase angle of the grid voltage. The coordinate transformation is widely used in the analysis of the motor system and it must keep power and magnetic motive force constant when using coordinate transformation. Energy storage technology can effectively improve the power regulation of micro-grid. LCL filter circuit can be a good suppression of micro network harmonics.The control principle of synchronous generator is analyzed, and the principle of active power and reactive power balance is analyzed. Based on this, the power frequency controller and excitation controller of VSG are designed, and the simulation model of VSG is established. The simulation results show that the power output of the energy storage system can be controlled by using VSG, which can maintain the stability of the micro network, and further improve the stability of the system after the dead zone is added to the system.