Fed Three-phase Pwm Rectifier

This project focuses on the research of three-phase PWM rectifier. The project is proposed as a solution to the drawback of traditional uncontrolled rectifier in the speed modulation of elevator system, and the bidirectional power flow of the speed modulation system. This project choose three half-phase voltage topology accord to the requirement of bidirectional power flow, and use TMS320F2812 as the controller to reach high performance of the converter.In this paper,we analyse the basic principle of the three-phase PWM rectifier,include the rectifier mode and the invert mode. We make a detail analysis of the mathmatics modeling,deduce the small signal model of the three-phase PWM rectifier in dq rotation reference frame. As to the control scheme,this paper propose a directly current control scheme,with fixed switching frequence in dq rotation reference frame. And also,we introduce current decoupling controlling and input voltage feedback,whitch makes the system more stable and faster response. The design processiong of the compensation tache is proposed,and verified in MATLAB.With the voltage space vectors pulsewidth modulation,we can get higher usage of the voltage. This paper discusses the principle of the space vectors in three-phase rectifier,and the implement of the space vectors.Two key problems are solved in this paper. One is the problem of synchronization with the grid; another is the distortion of the input phase current caused by deadtime-effect. We give the detail solution of the two problems.At the end of this paper, a 10kW three-phase rectifier is manufactured according to the design scheme proposed in this paper. The experimental waveforms verify the validity of the design in this paper.