The Research Of Methods On Three-phase Voltage-type PWM Rectifier And The Design Of DSP Controller

With the serious problem of harmonics pollution to the power system and theneed of high performance of AC drive application, much attention has been paid forthe PWM rectifier technology. Recently, it also has been an active research topic inpower electronics due to more virtues, such as sinusoidal input currents, unity powerfactor, steady output voltage, good dynamics and bin-directional energy flow.Firstly，this paper introduced the theory, topology, mathematical model andcontrol strategy of three-phase voltage type PWM rectifier amply，then it analyzed theworking principle of PWM rectifier at every work state，built the AC mathematicmodel of PWM rectifier based on the switching function and duty ratio underthree-phase stationary coordinate（a,b,c）,two-phase stationary coordinate （α， β）and the two-phase rotating coordinate （d,q） respectively. Also the paper studied theprinciple and composition of the direct power control system and the function of eachpart detailed. The traditional switch vector table was improved and auxiliary voltagevectors were given in switch state table，which decreased the impact of reactive powerin uncontrollable area, and also the new switch vector table was introduced. Theperformance of direct power controlled three-phase PWM was verified by simulation,which gained good steady and dynamic control effect. Finally, the three-phase PWMrectifiers experimental platform was built in the laboratory by usingTMS320LF2407A（a control core） and direct power control strategy. The design ofmain circuit, auxiliary circuit and hardware circuit including inductance, capacitance,etc, and the software were also introduced.The experiment result proves that the three-phase PWM rectifier with the directpower control strategy can achieved the virtues of high power factor, high efficiencyand low harmonics.