Bridgeless electrolytic capacitor-less valley-fill AC/DC converter for offline twin-bus light-emitting diode lighting application

摘要: To match the key features of light-emitting diode (LED) lighting source and further save power, LED driver also requires long life, while maintaining high efficiency, power factor, pulse-width modulation dimming low cost. However, a typical has following drawbacks: (i) utilise bulky electrolytic capacitor as storage with short lifetime; (ii) employ low-frequency bridge rectifier cell; (iii) engage multiple stages cascade structure for strings. overcome aforementioned shortages, this study proposed bridgeless capacitor-less AC/DC converter offline application. In converter, conventional rectified is replaced by Totem-pole configuration reducing number semiconductors in line-current path. Meanwhile, valley-fill circuit introduced to reduce size. As comparison its counterpart, only one quarter energy when considering amount (CV 2 ) sizing criterion. Furthermore, isolation type studied compatible Twin-Bus achieving higher overall system efficiency. Finally, experimental results, taken from laboratory prototype rated at 50 W, are presented verify effectiveness converter.