Output-Voltage-Tracking Control for Buck Converters Using Variable Convergence Rate Mechanism Without Current Feedback

This article aims to accomplish the output voltage tracking task for buck converters without current feedback, diminishing the performance degradation from model-plant mismatches and load variations. The following contributions overcome these difficulties: a) the combination of Luenberger and disturbance observer (DOB) techniques for a parameter-independent voltage-derivative observer; b) the pole-zero cancellation control incorporating the DOB and active-damping injection techniques; and c) the exponential convergence guarantee to the target tracking system subject to the variable convergence rate mechanism. Convincing experimental evidence confirms the effectiveness of proposed tracking control using a prototype 3 kW buck converter control system.