Symmetrical Dual Quadratic Step-Down DC-DC Converter For Solar Energy Storage

A dual quadratic step-down DC-DC converter with high step-down ratio and low component voltage stress is investigated. The symmetrical converter topology is described. In inductor current continuous conduction mode, operation modes and steady-state characteristics are discussed in details, while various components voltage stress are listed. Major power device losses are also calculated. Common-mode voltage of converter is briefly analyzed. The theorectical analysis are verified to be correct by simulation in SIMPLIS. A 700W prototype with 95.9% peak efficiency is built and tested. The experimental achievements show that the symmetrical converter has excellent voltage step-down capability, low component voltage stress, constant common-mode voltage and relatively high efficiency.