Abstract
This thesis presents the development of a single-stage flyback switch-mode rectifier (SMR) and performs the comparative study of two current-mode control approaches. The general issues concerning power quality, survey of existing SMR circuits and current mode control methods are first explored. Then the analysis, design, implementation and control of a flyback SMR under discontinuous conduction mode (DCM) are made. For facilitating the circuit component design, the ratings of flyback SMR circuit components are derived in detail. As to the dynamic control studies, the average current control using switch current is first made. Then a varying-frequency charge-regulated approach is developed. Wherein the switch turn-on time is fixed and the off time instant is determined by the low-pass filtered switch current and the current command generated from the outer voltage loop. No dynamic current control and slope compensation are needed. The proposed control scheme possesses the advantages of having dispersedly distributed harmonic spectrum, robust current tracking control, ease of implementation using off-the-shelf integrated circuits, etc. In voltage control loop, the dynamic model is estimated. Then the quantitative feedback controller design is performed by the developed design procedure. Some simulated and experimental results are given to demonstrate the performance of the established SMRs and the effectiveness of the developed control methods.