Optimization-Based Design of an Off-Line LED Driver Based on the LLC Resonant Converter With Active Ripple Compensation

This paper presents a design methodology for designing an off-line light-emitting diode (LED) driver, aiming to improve its efficiency, lifespan, and volume. The approach considers the entire design process as a nonlinear constrained optimization problem and allows for simultaneous design of power circuit elements and the controller, which uses a frequency-based active ripple compensation (ARC). By applying the ARC technique, the design achieves a substantial reduction in bulk capacitance, enhancing both lifespan and compactness. The proposed strategy provides flexibility, allowing designers to prioritize key performance indicators—such as reliability, volume, and power losses—according to specific design objectives. In order to verify the feasibility of the design procedure, the strategy was employed to a compact two-stage integrated topology based on the integration of a totem-pole bridgeless boost PFC and a half-bridge LLC resonant converter. Experimental results obtained from a 96-W laboratory prototype supplied from a 127-V 60-Hz mains voltage attested the superior performance of the optimized design. The proposed approach enabled an approximate 92% reduction in bus capacitance and a 30% reduction in overall driver volume compared to the conventional design methodology.