Study of Quasi Z-source Direct Matrix Converter based on New Strategy of Dual Space Vector Modulation

A quasi Z-source (QZS) network is coupled to the direct matrix converter (DMC) and a novel strategy of dual space vector modulation is proposed. It can effectively solve the defect of lower voltage transfer ratio of traditional matrix converter. The DMC which introduced the QZS can allow the three phase AC input side short circuit which defined shoot through state. It can achieve the AC input voltage boost conversion by controlling the time of shoot-through state in one switch circle. Also, it can keep the input current continuous and achieve the input LC-filter. First, the topology of QZS-DMC is analyzed and its boost operating principles are illustrated in detail. Then, the novel strategy of dual space vector modulation for QZS-DMC is expounded, especially a new modulation strategy based on the distribution of the working time of the shoot-through zero vector is first used in DMC. Finally, simulation is conducted in detail, and a elementary prototype machine controlled by FPGA and DSP TMS320F28335 is designed to experimental verification. The model of the major circuit was built based on the platform of Matlab/Simulink and the novel modulation strategy for QZS-DMC is realized by S-function modeling method based on C language programming, and then they form a whole system to conduct the simulation experiments. According to analyze the simulation results compared with the traditional matrix converter (MC), and the experimental results, the advantages of QZS-DMC and the new strategy can be well verified.