The Study Of Soft-switch PWM Rectifier

Due to the characteristics of high power factor and bidirectional power flow,PWM rectifier is the first choice of AC/DC,however,the soft switching technology of PWM rectifier is still in research compared with common realized of soft-switch DC/DC.The switching loss of the common PWM rectifier not only results in energy loss and efficiency,but also makes the switch tube hot,so the research on the soft switching PWM rectifier is helpful to reduce the switching loss and reduce the power loss.This paper introduces the background and significance of research on soft-switch PWM rectifier,a variety of soft-switch technology are introduced and compares their advantages and disadvantages,and finally puts forward the simple and soft-switch topology whose control algorithm is easy to realize.According to the proposed topology,this thesis starts from the principle of general PWM rectifier based on the establishment of a mathematical model of the multiple coordinate system,and analyzes the conditions for the resonant realization of soft-switch PWM rectifier based on the theoretical analysis.Secondly,this paper introduces the control strategy of the soft-switch PWM rectifier,especially introduces a variety of phase-locked loop strategy,and analyzes their advantages and disadvantages,to provide a theoretical basis for the selection of appropriate phase-locked loop.In addition,the control strategy of repetitive control +SVPWM modulation is proposed,which has the advantages of wide application range,low current harmonic,control stably and so on.In this paper,the hardware circuit design of soft-switch PWM rectifier is described in detail,including sampling circuit design,protection circuit design and communication design.Finally,based on theoretical analysis this paper a simulation model of matlab/simulink is built.According to the simulation model,an experimental platform is built.The simulation model and experiment is correspondence,and the experiment results of general PWM rectifier and soft-switch PWM rectifier are given to verify the correctness of theoretical and program design.