Digital Control of Switching Power Supply - Power Factor Correction Stage | Digital Control of Switching Power Supply - Power Factor Correction Stage Sangsun Kim and Dr. P. Enjeti Power Electronics and Power Quality Laboratory Department of Electrical Engineering Texas A M University College Station TX - 77843-3128 Tel 979-845-7466 Fax 979-845-6259 Email enjeti@ Abstract Industry standard for the control of switch mode power supply SMPS systems has been analog control. Now with the advent of high speed lower cost digital signal processing DSP ICs digital control there has been an increased interest in digital control of SMPS. The Power Electronics Power Quality Laboratory of Texas A M University is currently exploring several implementation aspects of digital control of power factor correction PFC stage of SMPS. Two low cost digital controllers TMS320LF2407 and ST52x420 are evaluated for implementing PFC function. Simulation and experimental results are shown to demonstrate PFC control of SMPS to meet IEC 1000-3 harmonic limits. I. Introduction Worldwide the markets of internal and external switch mode ac dc power supply SMPS have been growing at a faster rate for several applications such as communications computers instrumentation Industrial controls and military aerospace area 1 2 . According to resent estimates the world wide SMPS market share for power supplies notebook computer cellular phone modem and telecommunication equipment is expected to increase from about 20 billion in 2000 to 56 billion by 2005 for a compound annual growth rate . The majority of the present day SMPS employ analog control and are undergoing slow evolution. On the other hand enabling technologies such as digital signal processors DSP integrated semiconductors magnetics improved power components and cooling technologies are fast evolving. Tomorrow s SMPS is expected to be highly efficient with near unity power factor DSP control 10W per cubic inch and 400 A in the same size as 200A today. In response to the concerns this article evaluates the .
