Intelligent Inner Loop-Based Output-Feedback System for DC/DC Power Converters With Model-Free Observer

This paper presents an advanced observer-based cascade-type output-feedback controller eliminating the current loop and lowers the dependence level of the open-loop system for DC/DC power converters. The proposed solution provides several features: (a) a model-free pole-zero cancellation observer for the estimation of the output-voltage derivative to ensure that the implementations of the inner and outer loop are feasible; (b) an intelligent mechanism establishing a flexible inner-loop feedback gain level according to the transient and steady-state periods, and (c) an observer and intelligent inner loop mechanism-based, output-voltage derivative stabilization along the first-order system achieved by the active damping injection technique by pole-zero cancellation. A 3-kW DC/DC boost converter with a 32-bit digital signal processor demonstrates the effectiveness of the proposed technique.