Three-port Network for Single-Stage Bridgeless LED Driver with Power Pulsation Decoupling Capability

High-brightness light-emitting diodes (HB-LEDs) is next generation of green lighting. However, the bulky electrolytic capacitor in converters is required to compensate the difference of pulsating power, thereby restricting the lifetime of the whole system. Meanwhile, the existence of full-bridge rectifier circuit and multi-stage transformation hinders the further improvement of power density. In this paper, a three-port network for single-stage bridgeless LED driver is proposed with the way of sharing so as to reduce the use of devices, thus higher power density is achieved; and additional port dedicated to power decoupling function so as to dramatically reduce the decoupling capacitance, thus allowing for film capacitors to be used. Operating principle, design considerations and performance comparisons are examined in detail. Finally, all the superior performances of proposed LED driver are verified by the PSIM platform.