Design And Research On The Three-phase High Power Factor Rectifier

With the development of an economical society policy and the improvement of environment-protection consciousness, people are impelled to explore a "green way" in the development of electric and electronic technology. For a converter, "one green way" means that it can achieves a low THD, unity power factor and the control system has a higher performance, stability and efficiency which the traditional converter does not have. As the fast developing technology of green energy, an ever-enhanced attention has been focused on the PWM rectifier in the field of power electronics. PWM rectifier might become an ideal electric appliance or a linkage between grid-line and other electric facilities, characterized of pollution-free and adjustable power factor.The existing PWM rectifier can be divided into the voltage-source PWM rectifier (VSR) and the current-source PWM rectifier (CSR). The main circuit is consisted of six IGBTs. However, the VSR is only used in the low power field. Although the CSR can be used in high power field such as the metal industry, the cost of the IGBT for high voltage is high. Moreover the additional diode essentially doubles the conduction losses in the converter.This paper firstly compares various results of each circuit for the rectifier;then introduces the working principle of the PWM rectifier based on SCR, and giving the test circuit for the especial SCR;after that, the paper illustrates the converter's models and modulation functions, proposing a trigger circuit for IGBT and coordination between it and SCR. In order to achieve an intelligence control affect, the paper also applies PWM technology for a better result. Finally, the paper proposed some simulation waves of the different design circuit for rectifiers.The main character of the rectifier in this paper is the PWM technology based on SCR. This converter can be pulse width modulated and can achieve unity power factor. The circuit has low-cost, high-performance and is feasible for the engineering practice. This rectifier has more practical value.