An Improved Active-Clamp Resonant Forward Three-Port Converter With Voltage Coupling and Structural Simplification

Abstract

This brief proposes a simplified three-port resonant forward converter for low-power photovoltaic (PV) systems. The design aims to reduce power-stage component cost while ensuring sufficient regulation capability. Specifically, an auxiliary winding of the main resonant tank is magnetically coupled to the filtering inductor of the battery management circuit. This introduces phase-shift as an additional degree of freedom for gain adjustment, thereby eliminating the need for a dedicated pre-regulation stage. As a result, the proposed integration scheme reduces system complexity and power conversion stages, leading to improved power-board-level cost-effectiveness. Based on theoretical analysis, experimental results validate the proposed design.