Single-Stage Three-Phase AC-DC Resonant Switched Capacitor LED Driver Without Electrolytic Capacitor and Reduced Number of Controlled Switches

Abstract

This article proposes a three-phase resonant driver based on the resonant switched capacitor (RSC) for the light emitting diode (LED). The employed LED is chip-on-board (COB) based technology, resulting in a high power density. As the driver provides low current ripple and low flicker, it is not necessary to use electrolytic capacitor. This characteristic improves the driver lifetime. The two controlled switches operate under zero current switching (ZCS), which increases the driver efficiency. The LED dimming is enabled, only by varying the switching frequency. A 216 W laboratory prototype was designed to supply a LED device from an AC 220 V (60 Hz) voltage source. The LED driver is presented and discussed. Experimental results have shown power factor higher than 0.98, the percent flicker of 6.6% at 360 Hz and the efficiency of is 89%.