Simple and Effective Adaptive Deadtime Strategies for LLC Resonant Converter: Analysis, Design, and Implementation

An improved time‐domain analytical method for LLC resonant converters and dead time designs for zero‐voltage switching

“…Figure 13 shows that the required t dis in the experimental tests increased with increasing f s . The variation trend FIGURE 13 Comparison of the lower limits of the dead time t dis at different switching frequencies.…”

“…In ref. [13], a fitting expression for the curve of $$C_{\text{oss}}\text{--}v_{\text{DS}}$$ based on the natural exponential function was proposed: $$$$\begin{equation} C_{\text{oss}}{\left(v\right)}=a\cdot e^{b\cdot v}+c\cdot e^{d\cdot v} \end{equation}$$$$where a , b , c , and d are the coefficients of the expression, which are obtained from the $$C_{\text{oss}}\text{--}v_{\text{DS}}$$ curve in the datasheet and a curve fitting tool.…”

“…In ref. [13], a fitting expression for the curve of C oss -v DS based on the natural exponential function was proposed:…”

“…The method for calculating the equivalent capacitance of the transformer was not discussed in ref. [11] or [13].…”

“…In ref. [13], the traditional time-domain analytical method for LLC converters [7] and the charge expression in ref. [11] were combined to calculate the lower limit of the dead time for ZVS.…”