| Title |
Resonant Network Design Methodology of LLC Resonant Converter for Realizable Voltage Gain Achievement Considering ESR Effects |
| DOI |
https://doi.org/10.6113/TKPE.2026.31.3.181 |
| ISSN |
1229-2214(pISSN), 2288-6281(eISSN) |
| Keywords |
LLC Resonant Converter; ESR(Equivalent Series Resistance); FHA(First Harmonic Approximation); Voltage gain; Resonant network design |
| Abstract |
There is a difference between the theoretical and practical voltage gains of an LLC resonant converter due to the effect of the voltage drop by the equivalent series resistance (ESR) of the resonant network. As a result, the target voltage gain cannot be achieved. In general, the resonant network parameter is repeatedly adjusted to solve this problem, but this method increases the design complexity. This paper proposes a design methodology for the resonant network for the LLC resonant converter to achieve the desired voltage gain considering the ESR of the resonant network. A mathematical model of the voltage gain curve including ESR has been derived. On the basis of the model, the maximum voltage gain and its operating frequency can be calculated. In addition, the magnetizing current has been taken into account during the resonant network design to limit the primary side current to a reasonable value. The effectiveness of the proposed design method has been verified by both simulation and experimental results using a step-up 150 W LLC resonant converter prototype. |