Research Of Two Stage Matrix Converter Based On Svm Control Strategy

Matrix converter (MC) is a power converter with an advanced circuit topology. It has many virtues such as simpler structure, omitting the large reactive energy storage components, less harmonic pollution to the power network, drawing sinusoidal input currents and output voltages, allowing the input fundamental displacement factor to be set at unity or freely varied regardless of the load power factor. Besides these, it is capable of performing output voltages'amplitude and frequency conversion, and realizing bi-directional power flow. Because of these advantages, it has been the hot point of power converter research. And that, on account of reduced number of switchings and much simple control strategy compared to conventional matrix converter(CMC), two-stage matrix converter(TSMC) is a novel matrix converter with huge development potentials.Firstly, this paper briefly described the basic principle of the two-stage matrix converter, deduced the evolving process from CMC to TSMC, generally introduced several typical topologies and mathematical models of the TSMC, discussed the realization of the bi-directional switch, Introduced the four step commutation sequence which was widely used in CMC as well as the commutation sequence in TSMC, and gave theirs characteristic of each strategy through comparisons.Secondly, two kinds of space vector control strategy were analyzed in detail, that is rectifier stage without zero space vector modulation (SVM) strategy and rectifier stage with zero vector SVM strategy. Deduced the commonly used TSMC rectifier stage without zero vector SVM and improve it, make this stategy can conquer the localization of TSMC input power factor fixed on one only, and can adjust the power factor angle with limits. Then the double SVM strategy whitch is true of TSMC was proposed, the low frequent switching function of which was derived based on this, and a simplified strategy was proposed. Two simulation models of TSMC based on space vector modulation strategy were set up with MATLAB software, The simulation results showed the virtues of TSMC and verified the correctness and feasibility of the control strategy.Lastly, hardware circuits of the matrix converter control system based on the DSP chip was designed, including main circuit, DSP and its peripheral circuit, drive circuit,zero voltage detection circuit etc. The software was also designed by matching the hardware circuits.Through the theoretical analysis, computer simulation and experimental research, this paper discussed principal issues of the TSMC such as basic principle, control strategy, commutation strategy etc. Some valuable experiences and conclusions were given in the paper, which have referenced significance to further studies.