Research Of Matrix Converter With Voltage Closed Loop Control

Matrix converter is concerned more and more widely, because it permits frequency conversion, allows bi-directional power flow without middle DC link, and allows the input power factor freely varied regardless of the load power factor. Now the common control strategies are used in the open loop mode. In this paper, a voltage closed loop control strategy is used. The corresponding researchs have been investigated both computer simulation and prototype experiment.At first, the topology of matrix converter is introduced, and some popular voltage control strategies and their characteristic are discussed. Specially, the Space Vector Modulation is analyzed detailed. A mathematical method is used for proving three phase three phase matrix converter equal to the VSI-VSR converter, and virtual rectifier and inverter are both discussed respectively, finally the synthesis Space Vector Modulation has been received. To reduce the high-order harmonic caused by asymmetric modulation, a cross modulation is used. Based on it, a optimization switched method is used which can reduce switched number and losses, improve input and output performance.Because the output voltage can't adjust itself to against the input disturbance under the open loop control mode, a closed loop method is used. By coordinate transformation for abc to dq , the output voltage can be transformed to space vector, then compared with the expected voltage,the errors can be used for feedback and controlling. Matlab simulation is used for certification.Based on the simulation, a three phase three phase matrix converter both the main circuit and the control system has been established, which used TMS320LF2407A for the main controller. It's function includes Space Vector Modulation, voltage A/D sampling, voltage closed loop control and display. Results of voltage closed loop experiments certificate the feasibility of the method which is used in this paper.