Research On A Digital Control For Single Phase Power Factor Corrector

Commutating 220V AC to DC is the most basic application of the rectifier programs in power electronics technology. However,it results in input current distortion and input power factor greatly decrease. With promulgation and actualization of IEC-1000-3-2 and EN61000-3-2 etc.internationnal standards,Power Factor correction (PFC) technique become a hotspot of research in power electronics field . With the development of digital control chip and digital control technology , more and more algorithms can be implemented in power electronics by the digital signal processors(DSP). Nowadays it is popular to use digital control in power supply design.Based on the average current mode,the dissertation introduce the design and implementation of a digital controlled single-phase PFC controller based on the main circuit used Boost converter topology. The control-loop circuit is realized using digital control ,and ultimately make the rectifier with power factor correction to increase power factor and reduce current harmonics .The double closeloop framework is applied in the PFC control circuit and the PI algorithm is adopted as system's control algorithm. Dissertation first introduced the PFC digital control theory, then researched the system's small-signal model and established the system's small-signal model. On the basis of the establishment of the small-signal model, it specific gives the design of PI regulator for the double-loop system, and simulation results show the correctness of the design and the feasibility of the experiment. Then the hardware design and software design are presented. Furthermore, the main program flow chart are given. At last,a digital controlled single-phase PFC test system is introduced and a good experimental waveforms is made. In addition,the sampling algorithm of votage and current variables is also analysed in this dissertation.The experimental results confirm the correctness of the theoretical analysis and the feasibility of the control scheme. Anticipation is realized.