Analysis and Design Considerations of a Simplified LLC Three‐Port Resonant Converter

The growing demand for photovoltaic (PV) systems with integrated energy storage poses challenges for power conditioning, often requiring multiple converters that increase cost, complexity, and losses. Multiport resonant converters have emerged as an efficient alternative by integrating PV modules, energy storage systems (ESSs), and a DC bus within a single topology. The triple active bridge (TAB) is the most common solution, but its high semiconductor count raises costs and reduces efficiency. This paper proposes a simplified three‐port LLC resonant converter tailored for standalone PV–ESS applications, where only the battery port requires bidirectional operation. A major contribution to this work is demonstrating that a three‐port LLC resonant converter with a reduced number of switches can achieve competitive performance while simplifying implementation. In particular, the use of a Class D amplifier in the PV port and a two‐diode rectifier in the DC bus port enabled a reduction in both component count and conduction losses, without compromising the converter’s flexibility for renewable energy applications. The topology reduces the number of semiconductor devices compared to TAB converters while maintaining galvanic isolation and soft‐switching capability. The design was validated through analytical modeling, SPICE simulations, and a laboratory prototype operating in four modes. Experimental results confirmed stable resonant operation with efficiencies above 88% in all modes, reaching up to 90.1% with SiC MOSFETs. The results demonstrate that the proposed topology combines reduced complexity, competitive performance, and high efficiency, making it suitable for standalone renewable energy systems with integrated storage.