A two-stage LED street lighting system based on a novel single-stage AC-DC converter

A two-stage LED street lighting system is proposed in the paper, the first stage is a single-stage AC-DC converter based on sepic circuit and flyback circuit. The sepic circuit and the flyback circuit are integrated by sharing one switch, since the components of the converter decrease, the converter has high efficiency and high reliability. The switch of the converter works in the quasi-resonant (QR) state, which decreases the switching losses and increases the efficiency of the system. The second stage is a constant current circuit, the boost circuit with peak current control is adopted here, and LT3756 is used to achieve the constant current control. A 100W prototype is proposed in the lab, which proves the feasibility of the proposed converter, the soft switching is achieved and the efficiency of the system can be higher than 83% in full load.