Current-ripple-based control strategy to achieve low-frequency ripple cancellation in single-stage high-power LED driver

This paper proposes a new current-ripple-based control strategy for the Series Ripple Cancellation Converter (Series RCC), which eliminates LED light flicker caused by Power Factor Correction (PFC) stage and significantly reduces its output capacitance. Instead of sensing two differential output voltage signals as in existing voltage-ripple-based control strategy, the proposed current-ripple-based control strategy achieves series ripple cancellation only by sensing the LED current information. The proposed control strategy significantly simplifies the control circuitry. In addition, the proposed control strategy allows input voltage of the Series RCC to tightly track its output voltage peak value with no extra control circuit, thus minimizing the RCC component voltage stress as well as the RCC loss. A 100W, 150V-0.67A experimental prototype has been built to demonstrate the advantages of the proposed method.