Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Analysis for Light Load Regulation of LLC Converter using Bode Plot
Authors Cheol-O Yeon ; Gun-Woo Moon
DOI 10.6113/TKPE/2016.21.6.506
Page pp.506-513
ISSN 1229-2214
Keywords LLC converter; Light load regulation; Parasitic components; ZVS(Zero-Voltage-Switching); Bode plot; Impedance asymptotes
Abstract In general, LLC converters show great promise in applications that require high efficiency, especially under light load conditions. In particular, LLC converters feature wide gain capability with pulse-frequency modulation and zero voltage switching over entire load conditions. However, output voltage increases in light load conditions. In this study, Bode plot and impedance asymptotes analyses were conducted to obtain insights into the regulation characteristics of LLC converters under light load conditions. To improve the regulation characteristic of LLC converters, a new resonant tank with an additional capacitor is proposed. The design guideline for the proposed LLC converter is determined by the Bode plot and impedance asymptotes analyses. Therefore, the proposed LLC converter achieves the light load regulation while maintaining the advantages of typical LLC converters.