AB  - LLC converters operating across wide input voltage ranges tend to deviate from their optimal efficiency point, leading to a decline in overall performance. The flying capacitor based isolated resonant converter (FCiRC) with its frequency multiplication capability, is a viable candidate for high power density converter design. It offers a high step-down conversion from 800 V input to 48 V regulated output. Nevertheless, limiting its boundaries, the existing modulation scheme does not allow for a wide-input range operation. Addressing this shortcoming, the current work proposes three additional modulation strategies allowing the converter to operate under a wide input voltage ranging from 160 V to 960 V, delivering a regulated 48 V output. The converter maintains a stable efficiency of approximately 91 % across all modulation strategies, while preserving its key benefits-such as simplified magnetic design despite wide frequency variations across modes, and lower voltage stress on the switches. Experimental validation of the proposed modulation strategy has been presented.
AU  - Palanisamy, A
AU  - Hassan, J
AU  - Lu, D
AU  - Aguilera, RP
AU  - Siwakoti, YP
DA  - 2025
DO  - 10.1109/ECCE58356.2025.11259525
JO  - 2025 Energy Conversion Congress and Exposition-ECCE-Annual
PB  - IEEE
PY  - 2025
TI  - Extended Modulation Strategy for Wide Input Range Flying Capacitor based High Step-down LLC Resonant Converter
VL  - 00
Y1  - 2025
Y2  - 2026/05/25
ER  -