The Study Of Three-Phase Voltage Source PWM Rectifier And Control Strategy

At present, traditional diode rectifier and phase controlled rectifier has become a usual AC/DC transform form of medium and top grade transducer because their simple structure and ripe technology. But with the rapidly development of green energy technology, the electronic and the magnetism disturb and the harmonic pollution from un-controlled rectifier have become a serious problem. So now, PWM rectifier is a new and hot technology in electric power research. It has many advantages such as making the grid current approach to sine wave, grid power factor come to l,four quadrant circulate, rapid motion response, power duplexing transfer,DC voltage controllable and load disturb resistible. So it is really energy saving and green.The paper introduces the theory of PWM rectifier detailedly and deduce the math model base on switch function, then deduce the two-phase quiescent reference frame and two-phase rotary reference frame math model after using the reference frame transform. Besides, it introduces the current transform mode and deduce the selection principle of the main circuit parameter.The paper analyse the sine pulse width modulation contrast with the space vector pulse width modulation (SVPWM),then analyse current control strategy intensively for PWM rectifier, discuss indirect current control and direct current control base on three-phase reference frame. it contraposes voltage oriented control,importing space vector PWM(SVPWM) and feedforward control method, design a control system base on voltage oriented control which contains double loop . Moreover, considering the cost problem for PWM rectifier, it introduces the theory of virtual line flux oriented vector control without voltage sensors and virtual line flux oriented vector control without current sensors.The paper designs the PWM rectifier hardware circuit base on voltage oriented control. This system includes main circuit, control circuit, sample circuit and synchronization circuit, and provide the design project. It takes TI DSP 2812 to achieve PWM rectifier's double loop digital control.In the foundation of theory analysis, using Power Electric toolbox offered by MATLAB to finish the simulation experiment under Simulink environment and to verify systematic exactness and feasibility by analyzing the simulation results. The research production of this paper will offer practical value to research and develop PWM rectifier.