Research On The PWM Rectifier With High Power Factor For Three-Phase Voltage Mode

Along with the modern economic fast development, the people have more and more requirement for electricity energy, which makes the pollution in the net of electricity very severity. The past rectifier has not satisfied the modern need. Because of this pollution, the rate of electricity accident is going up, and also takes the danger into the life of people, so we must take some measures to resolve this problem.Based on the development of science and technology, PWM rectifier technique has been researched. In the past 20 years, there are some limitations for rectifier, for example, the power factor is low, and the pollution of harmonic elements is very severity and so on. But now PWM rectifier has overcome these problems. For the PWM rectifier, the power factor is improved; it also can eliminate harmonic elements and reduce the switch frequency.Firstly, the dissertation discusses the problem of power factor, the principle of PWM rectifier, the control instrument of PWM rectifier, and the configuration of circuit. The modulation principle of the voltage space vector (SVPWM) and its digital realization method are analyzed too. Secondly, the hardware design of the three-phase voltage-type PWM rectifier are presented in detail, including the choice of inductance and capacitance, the design of main circuit, signal conditioning, control circuit, the circuit parameters and the control of fuzzy PI circuit; Thirdly, programming of control is described. The programming mainly contains interrupt service routines, digital PI control algorithm, SVPWM modulation and keyboard and display program. Finally, a math former was established for SVPWM, and summarize and discuss the result of emulator.Experimental results show that operation of the bidirectional PWM rectifier base on SVPWM modulation cannot only eliminate harmonic elements and improve power factor, but also reduce the switch frequency. Research on the Three-Phase High Power Factor PWM Rectifier has been one of the most measures for harmonic pollution.