Light-emitting-diode (LED) has favorite features of environmental protections and energy-savings; there-fore, it is going to take place of a high-pressure mercury lamp and play an important role as a new and advan-tageous lighting source for streetlight applications. The conventional two-stage LED streetlight driver is com-posed of an AC-DC converter with power-factor-correction (PFC) and a DC-DC converter. The conventional LED streetlight driver has more circuit components, higher cost and limited efficiency. Therefore, this technique presents a novel single-stage LED streetlight driver with PFC and soft-switching features, which integrates a totem-pole bridgeless boost converter with half-bridge LC series resonant converter into a single-stage power-conversion topology. The inductor inside the totem-pole boost converter is designed to operate at discontinu-ous-conduction mode (DCM) for naturally achieving PFC. Besides, zero-voltage switching (ZVS) is achieved in the proposed LED streetlight driver to lower the switching losses of power switches; thus, improvement of the power-conversion efficiency in the proposed circuit is achieved.
A 165W (235V/0.7A)-rated single-stage prototype LED streetlight driver has been developed and implemented in the technique. From the experimental results at an input utility-line voltage of 110V, high power-factor (PF) (>0.98), low total-harmonic-distortion (THD) of input current (<10％), low output-voltage ripples (<3％), low output-current ripples (<7％), and high circuit efficiency (>91％) are obtained in the proposed single-stage LED streetlight driver.