Design of high-efficiency power conversion system for low-voltage electric vehicle battery charging

This paper proposes a design of high-efficiency power conversion system for low-voltage electric vehicle battery charging. The proposed system consists of two power conversion stages: a single-phase ac-dc rectifier for power factor correction and an isolated dc-dc converter for battery charging. Compared to the conventional boost ac-dc rectifier, the proposed bridgeless ac-dc rectifier has advantages of reduced conduction losses, minimized device components, and improved power factor. Compared to the conventional phase-shift modulated (PSM) dc-dc converter, the proposed dc-dc converter has advantages of reduced switching losses, minimized circulating current, and improved power efficiency. As a result, the proposed system has improves the power efficiency when compared to the conventional system. All control functions are implemented in software with a singlechip microcontroller. The performance of the proposed system is evaluated throughout experimental results for an 800 W prototype for a 60 Hz/220 V_rms ac power grid.