Efficient two-stage offline driver for extra-high-current COB LED applications

摘要

This work proposes a reliable and efficient two-stage driver solution for extra-high-current (EHC) chip-on-board (COB) light-emitting diode (LED) applications. An ac-dc boost converter operating in continuous conduction mode is employed to provide input power factor correction and regulated dc-link voltage. Considering that EHC COB LEDs often operate at higher current levels than those employed in conventional high-powered lighting applications, a dc-dc extended gain interleaved buck converter (EGIBC) is employed so that power control is achieved. The average state-space modeling of the EGIBC is derived, while a digital control system is also implemented for this purpose. A 500-W prototype of the proposed two-stage topology is implemented, which does not require electrolytic capacitors. The obtained results clearly demonstrate that the proposed driver complies with international power quality and flicker standards. Thus, it can be consolidated as a viable choice for practical applications involving outdoor floodlighting where high luminous flux is mandatory.