Parallel Study Of Three Phase High Frequency Link Matrix Inverter

In recent years,distributed power generation technology continuously develops,as one of the important research directions,the inverter parallel has been a lot of research,regular inverters of parallel can increase the capacity of the system and improve the reliability and redundancy of the system.With the development of distributed technology,people's requirements are getting higher and higher,because the ordinary inverter uses the power frequency transformer to achieve electrical isolation and voltage matching,which leads to large volume,loud noise and the heavy weight of the parallel system,and it is not convenient to install.The parallel connection of three-phase high frequency link inverter can not only achieve the advantages of the above parallel system,at the same time,because it effectively reduces the weight and noise of the parallel system with the use of a high-frequency transformer,it can also make the system easy to install and debug.However,the research of high frequency link inverter parallel system is not mature.Therefore,it is of great practical significance to study the parallel connection of three-phase high-frequency link matrix inverters.In this paper,three phase high frequency link matrix inverter parallel system is studied,firstly,the mathematical model of three-phase high frequency link matrix inverters with de-re-coupling integration SPWM strategy modulation is analyzed,and the high frequency link inverter is modeled and analyzed,on the basis of modeling and analysis,filter inductor capacitance parameters and the system's closed-loop parameters are designed in detail.Secondly,this paper analyzes the parallel structure of three phase high frequency link matrix inverter,and studies the parallel model of two three-phase high frequency link inverter,then the droop control method under different output impedance characteristics is studied,based on the above analysis,a new power filtering method based on second order generalized integrator(SOGI)is proposed,this power filtering method effectively solves the shortcomings of the traditional low-pass filter with delay characteristics,reduces the number of filters,and improves the system waveform quality.The simulation research iscarried out by Matlab/Simulink software,and then the corresponding simulation waveforms are obtained.Then,the circulation of the parallel system of the high frequency link matrix inverter is analyzed in this paper,and the impedance characteristics of the inverter parallel system are analyzed mathematically.Then the paper studies traditional virtual impedance control,and the method that the traditional virtual impedance control is improved,a new method of the combination of improved power filter and virtual impedance based on SOGI is proposed,this method can effectively reduce the number of SOGI in traditional virtual impedance control based on SOGI,it simplify the program structure,and reduce the influence of output current noise on the system,and improve the output voltage quality,finally,the simulation results of the control method are analyzed by Matlab/Simulink software,and the simulation results of the parallel system resistance load and rectifier load are analyzed.Finally,the experimental study of the three-phase high frequency link matrix inverter system is carried out based on theoretical analysis and simulation analysis.The hardware of the experimental system is designed and the whole system is controlled by DSP chip and CPLD,the experiments validate the feasibility and correctness of the new method.