On randomized harmonic spectrum control for a flyback switch-mode rectifier

This paper presents the spread harmonic spectrum control for a flyback switch-mode rectifier (SMR). First, the power circuit is designed and implemented. A charge-regulated switching scheme and a robust voltage controller are designed to yield robust DC output voltage regulation response with good AC line drawn power quality. Next, the current harmonic spectral properties of the developed SMR are observed analytically. Then accordingly, the random switching schemes are developed and comparatively evaluated their harmonic spread distribution characteristics. The proposed random switching schemes belong to constant turn-on period with turn-off periods being modulated via binary sequence and pseudo random binary sequence (PRBS). The validity and performance of the developed flyback PFC rectifier are demonstrated experimentally.