A Comprehensive Analysis of Capacitance Network Models of Planar Transformer Across Converter Operating Scenarios

Abstract

This study investigates the accuracy and reliability of various capacitance network models for planar transformers typically employed in isolated converters. Parasitic capacitances significantly impact converter performance, affecting zero-voltage switching, efficiency, and electromagnetic interference (EMI). To analyze and evaluate the impact of parasitic capacitances across the converter operating scenarios, a capacitance network model can be used. However, previous studies have not comprehensively assessed the accuracy of these capacitance network models across converter operating scenarios, nor fully explored how transformer structure affects model accuracy. To address these gaps, this study performed simulations and experimental validations to evaluate various capacitance network models across different transformer structures and operating scenarios. The impedance of the planar transformer was used as a benchmark for assessing the accuracy of these models in various scenarios. Four distinct capacitance network models were analyzed across four transformer configurations and six operating scenarios. Results indicated that two models of four models demonstrated consistent accuracy under all conditions. These models are, therefore, recommended to be utilized to analyze the impacts of parasitic capacitances across converter operating scenarios, regardless of the winding structure.