Accurate Prediction of Incomplete Zero-Voltage Switching Dynamics and Losses

Abstract

The switching losses occurring between full softswitching and hard-switching are described inadequately, and previous attempts of quantifying incomplete zero-voltage switching losses are topology specific and not applicable for any general half-bridge circuit. The ability to quantify these losses is crucial to optimize the converter efficiency across a wide operating range. This paper proposes a general method for accurately estimating the incomplete zero-voltage switching dynamics and losses in halfbridge converters, including the non-linear output capacitance of the semiconductors. The charge balance during the switching transition period is solved to determine the depth of incomplete zero-voltage switching, which can be used to predict the switching losses. The method is verified experimentally, and is shown to be able to predict the depth of incomplete zero-voltage switching accurately, which can be used to calculate the related losses.