High-Efficiency Isolated Multiport Bidirectional DC-DC Converter for PV Applications

This study introduces a novel Isolated Multiport Bidirectional DC-DC Converter (IMBC) aimed at enhancing energy conversion and management in photovoltaic (PV) systems. The primary objective of the proposed converter is to optimize power flow between multiple sources and loads, while improving overall system efficiency and reliability. By integrating active snubber circuits and advanced soft-switching techniques, the IMBC reduces switching losses and minimizes overvoltage occurrences during switch-off events. The converter employs Zero-Current Switching (ZCS) to further decrease switching losses, thus improving both efficiency and operational performance. A 150 W prototype with a 120 V output voltage was developed and tested, achieving peak efficiencies of 98.5% in step-down mode and 96.4% in step-up mode. Throughout a wide range of operating conditions, the IMBC consistently maintained efficiency levels above 95%. The proposed IMBC design is highly suitable for PV power applications and energy storage integration, offering significant improvements in efficiency, reliability, and adaptability to various operating scenarios.