Comparative Analysis on Series Resonant Converter and CLLC Resonant Converter for Micro-Inverter Application

Abstract:
This paper proposes a series-resonant fixed-gain topology for front-end single-phase inverters to address the efficiency limitations of conventional variable-frequency CLLC converters in photovoltaic and energy storage applications. Through comparative analysis under different operating conditions, we demonstrate that fixed-frequency operation at the resonant point significantly reduces DCDC side losses by optimizing impedance matching, thereby enhancing overall system efficiency. These findings establish a novel design paradigm in which fixed-gain architectures utilizing widebandgap semiconductors operating at the resonant frequency outperform traditional frequency-modulated topologies in efficiency for single-phase inverter systems.