Single-Phase Power Factor Correction Techniques 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). However input current distortion at the zero-crossing of the input voltage is a common problem in active PFC converters, and it becomes more serious as the line frequency is increased. The purpose of this thesis is to reduce the zero-crossing distortion of input current at high input frequency application.This thesis analyzes the zero-crossing distortion, and points out that the major causes are the inductor and the phase displacement between the input current and the input voltage. Several methods are proposed and verified by simulation.To reduce the inductor and the phase displacement between the input current and the input voltage simultaneously, Multi-level (ML) converters are adopted as the PFC topologies in this thesis. The characteristics of three-level (TL) converter and its effect to the zero-crossing distortion are analyzed, and extended it to ML converters, which are suitable for the high input frequency PFC application.This thesis discusses the design of both the main circuit and control circuits of Boost TL converter, and a prototype converter is built in the lab. Also a prototype for the Boost two-level converter is built. The experimental results show that the Boost TL converter has lower input current harmonics than the Boost two-level converter, and it can satisfy the limits specified in RTCA DO-160D. So the Boost TL converter has the potential to apply in the future variable frequency AC airborne system ranged from 360Hz to 800Hz.