Design of a Low-Order Sensorless Controller by Robust H∞ Control for Boost Converters

Abstract

Luenberger observer (LO)-based sensorless multi-loop control of a converter requires an iterative trial-and-error design process, considering that many parameters should be determined, and loop gains are indirectly related to the closed-loop characteristics. Robust H∞ control adopts a compact sensorless controller. The algebraic Riccati equation (ARE)-based and linear matrix inequality (LMI)-based H∞ approaches need an exhaustive procedure, particularly for a low-order controller. Therefore, in this study, a novel robust H∞ synthesis approach is proposed to design a low-order sensorless controller for boost converters, which need not solve any ARE or LMI, and to parameterize the controller by an adjustable parameter behaving like a "knob" on the closed-loop characteristics. Simulation results show the straightforward closed-loop characteristics evaluation and better dynamic performance by the proposed H∞ approach, compared with the LO-based sensorless multi-loop control. Practical experiments on a digital processor confirmed the simulation results.

Sensorless Control for DC–DC Boost Converter via Generalized Parameter Estimation-Based Observer

“…It is noted that the exponential stability of a closed-loop system is ensured. It is reported in [20][21][22][23][24] that the well-known Luenberger observer is designed to reconstruct the current under continuous conduction mode (CCM) or discontinuous conduction mode (DCM). By combining this with some advanced controllers, sensorless controllers are derived.…”