An LLC Resonant Half-Bridge Converter Optimal Design Using First Harmonic Approximation: A Complete Step-by-Design

Abstract

There are several industrial uses for LLC resonant converters. The outcome of the converter is greatly influenced by the design and analysis methodologies used. An LLC resonant converter has been designed based on first harmonic approximation (FHA) modelling, and an optimal design technique has been provided in this work. The goal of this research is to provide a thorough design technique for an LLC resonant converter, based on rigorous quantitative analysis of the circuit’s steady-state performance. This study uses FHA technique, which greatly facilitates the model of the system, resulting in a linear circuit that can be analyzed using a standard complex ac-circuit analysis. The FHA methodology is used to establish circuit characteristics and to estimate the outcomes. Although half-bridge power converters are frequently employed in isolated, converters with high-voltage inputs, and medium-power applications are frequently constructed with resonant switching to increase efficiency, a feature that adds complexity but also provides various performance benefits. Two major benefits of the LLC resonant architecture are the soft-switching capabilities of the Power MOSFETs and secondary rectifiers, as well as the ability to operate at zero load. Additionally, the LLC resonant converter is simulated and the results are confirmed using PSIM.