Research On Power Factor Correction Technichques For Airborne System

Electronics equipments have been widely used, causing harmonics pollution to AC power lines. In order to solve this problem, the power factor correction(PFC) pre-regulators are applied to limit the input current harmonics of the switching power supplies.Active PFC techniques have been researched systematically and used widely in the recent twenty years because of high power factor(PF)and low total harmonic distortion(THD). With the increment of airborne power equipments, a large number of harmonic currents flow into airborne system, which have polluted airborne system and may result in abnormal work of airborne system and power equipment. In order to assure airborne power equipments to work safely and reliably, power factor requirements are necessary for airborne power equipments. The purpose of this paper is to emply power factor techniques to limit the input current harmonics of airborne system to meet some airborne standards.To limit harmonics pollution, a two stage PFC converter is researched in this paper. Its structure and operation principle are analyzed in details in this paper and control method is also proposed. In the low power situations, single stage PFC techniques can make AC/DC power supplies meet the harmonic standards and have low cost and good performance, so in this thesis the two stage PFC converter has been changed into a two-switch single-stage PFC converter.Operation principle of the single-stage PFC converter is analyzed in details, control method is also proposed and comparision between the single stage PFC converter and the two stage converter is given in several respects which are input current THD, PF, the converter weight and volume, output performance and the converter efficiency.The detailed design method of main circuit and control circuit is given in this thesis. The paper calculates the power losses of every part of a single stage PFC converter and a two stage converter and the efficiency of the converter may be further optimized.Prototypes of a single stage PFC converter and a two stage converter are built and tested in the lab. The experimental results verify the correction of theory analysis and design.