Research On Two-line Voltage Modulation Strategy Improvement Of Matrix Converter

Matrix converter(MC)as a new type of converter with the following characteristics: can directly achieve the two-way flow of electricity;input and output are sinusoidal waveform;the load can reach the power factor of 1;no inductance or capacitance of the DC Energy storage link.There are many factors that restrict its marketization,and one of the key factors is the selection of modulation strategies.The choice of MC modulation strategy can directly affect the performance of its output.The choice of the appropriate control strategy can not only improve the output voltage transmission ratio,the output side of the power factor,but also can improve the input and output waveform quality.In this paper,the dual voltage modulation strategy of MC is studied.This paper describes the three-phase input three-phase output MC topology and principle.The dual voltage modulation strategy of MC is analyzed,and an improved double voltage control method is proposed for the uncertainty of the duty cycle of the double voltage control method under the traditional sector combination.This method deduces the expression of the duty cycle of the switch under the improved method and the mathematical expression of the voltage conversion of the general output line by re-dividing and marking the voltage sector.The improved method not only can reduce the difficulty of control,but also can get the ideal sine wave.When the three-phase input voltage amplitude is not equal,the improved method can get a sine wave,indicating that the improved method of the unbalanced input voltage also has a resistance.After the study of Matlab2012 a / Simulink simulation platform,an improved simulation model of double voltage control strategy is constructed.Finally,the main circuit of the matrix converter and its digital control system are studied.A double voltage control system with DSP + CPLD as the main control circuit is designed,and the experiments with resistive load are completed.The experimental results verify that the proposed method The correctness of the theory.