Standalone Electrolytic-Capacitor-Less Universal Input Voltage LED Driver based on Parallel Integrated Converters using Variable Inductance to Compensate Input Voltage Variation

This paper presents an electrolytic-capacitor-less LED driver. The driver is made up by the integration of two converters in parallel. The first converter is a Buck-boost used to deliver constant current to the LED load, named as Power Control (PC) stage, while working as power factor correction meanwhile. The parallel converter is a Boost employed to reduce the ripple in the LED current, named as Ripple Reduction (RR) stage. This integration creates the Integrated Parallel Buck-Boost and Boost Converter (IPB3C), which shows great performance. However, the variation of any operation parameter affects both the efficiency and ripple reduction. Thus, creating a universal input voltage range driver is not straightforward. This paper proposes a variable inductor solution that will control both circulating power and ripple reduction percentages and eliminates the effect of the input voltage range variation.