Improving LLC Resonant Converter Efficiency through Optimal Capacitor Selection and Configuration

Abstract

The optimization of LLC resonant converters' efficiency depends greatly on the selection and configuration of resonant capacitors. By evaluating different capacitor groupings and their equivalent series resistance (ESR), the impact on overall converter performance is clearly demonstrated. Low-ESR capacitors are crucial for minimizing power losses, thus improving efficiency. The converter's behavior under various conditions is analyzed in MATLAB/Simulink. This paper highlights the necessity of optimal capacitor configurations to achieve high efficiency and confirms that the selection and configuration of capacitors significantly impact the efficiency of LLC resonant converters. Capacitors with high ESR values lead to increased power loss, negatively affecting performance. By using low-ESR capacitors and optimizing their configurations, efficiency improvements from 97.70% to 98.29% were observed.