Dsp-based Control Of Power Factor Correction Technology Research And Application

With the extensive application of power electronics devices, the current harmonic problem becomes more and more terrible. The current harmonic pollution brings a series of harms to system and electromagnetism environment .Under this background , Power Factor Correction (PFC)Technology which is being used in many fields becomes important part and research hotspot of the power electronics technology.The PFC converters with middle or large out power usually work under continuous-conduction-mode(CCM), which have the advantage of low current stress on the switch. However, Which exists severe diode reverse recovery problem in the CCM PFC converters. It may lead to high switching loss and cause severe EMI problems.The characteristics of traditional analog PFC converters is analyzed, the principle and working mode is studied. Compound Active-Clamp topology is proposed in this paper. This topology can effectively suppress the diode reverse recovery, meanwhile create zero-voltage switching for all the switches. Under this circumstance, the dynamic switching loci of switches are proved greatly and the switching loss is reduced. The topology can also eliminate the unwanted voltage oscillation in the traditional active clamp topology. The theoretical analysis and design details of Compound Active-Clamp PFC circuit is proposed. The control-loop circuit is realized using digital control, and ultimately make the rectifier with PFC to increase power factor and reduce current harmonics.Traditional PID control is hard to use in the great nonlinearity and parameter variety of central conditioner. In order to ensure the system stability, the author brought forward a digital control circuit scheme and an Immune Feedback PID control algorithm. The computer simulation result and the prototype validated the feasibility and validity of the proposed theory.At last, A 1KW Compound Active-Clamp PFC test system is introduced based on TMS320LF2812. The author made a clear explication of control circuit and soft design. It is presented waveform of prototype to prove the feasibility of this research.