Research On Grid Connected Technology Of Matrix Converter Based On Virtual Synchronous Generator

Global environmental problems are becoming more and more serious,and people are paying more attention to the development of clean energy in order to alleviate the problem of environmental pollution.Distributed energy is an important part of clean energy,but the problem of friendly grid connection of distributed energy has been plagued by scientific researchers.In order to make grid-connected inverters have the same grid-connected characteristics as synchronous generators,virtual synchronous generators(VSG)came into being.The proposal of this method has realized the friendly grid connection of distributed energy.At present,VSG technology is mainly based on inverter topology,so AC-AC conversion cannot be directly realized.If distributed energy sources with AC output are connected to the grid,complex AC-DC-AC conversion is required.The direct matrix converter(Matrix Converter,MC)is a kind of direct AC-AC conversion,and has the advantages of compact structure and simple control.This paper proposes a VSG grid-connected technology with MC as the main topology.It provides a direct AC-AC conversion idea for the grid-connected distributed energy with AC output,and provides a solution for matrix converters based on virtual synchronous generators(Matrix Converter based Virtual Synchronous Generator,VSG-MC)grid-connected technology to carry out in-depth research.First,it briefly introduces the research status of MC and VSG technology and the relationship between the two.In view of the particularity of the VSG-MC modulation algorithm,MC’s traditional space vector modulation is no longer applicable.First,the MC direct space vector modulation is analyzed,and a new type of space vector modulation is applied on this basis.This method only needs to output The voltage is sampled and modulated to generate the MC modulation signal,and the two control strategies are simulated and analyzed separately.Secondly,in order to better connect the distributed energy output by AC to the grid,this paper proposes a VSG-MC grid-connected technology.Aiming at the problem that the traditional virtual synchronous generator system may have a large inrush current at the moment of grid connection,the grid-connected voltage mutation analysis is carried out,and the pre-synchronization control is improved,so that the system can achieve smooth grid-connection without major problems.electric shock.The dynamic performance of the system is analyzed,the inertia and damping parameters of the matrix converter system based on the VSG are adjusted,and the system operating parameter values are calculated,so that the VSG technology can be better combined with the MC grid connection.Finally,the traditional VSG and VSG-MC grid-connected technical model was built.The simulation results show that the VSG-MC grid-connected technology is correct.And build the VSG-MC experimental platform to verify the new MC control method and the VSG technology with matrix converter as the main topology.From the experimental results,we can draw conclusions about the feasibility of the VSG-MC scheme.