A Novel Interleaved Single-Stage AC/DC Converter for Two Stage LED Street Light System

A two-stage street lighting system is presented, where the front stage is a single-stage AC/DC converter based on the interleaved sepic circuit and flyback converter. Since the interleaved sepic circuit and flyback converter share a switching device, the costs of the system can be reduced, the efficiency, reliability can be improved and ripple current get reduced. At the same time, the switch operates in quasi-resonant state, which reduces the switching losses and enhances the efficiency. The second stage is a light-emitting diode constant current circuit, which achieves the constant current control by adopting boost circuit in peak current control mode.