Robust LMI-Control of a Boost Converter Supplying Constant Power Load

Abstract

This paper presents the synthesis of a robust LMI-based controller for a boost converter supplying a constant power load (CPL). The converter connects a DC bus to a CPL requiring regulated output voltage. In the absence of control, the system may exhibit unstable behavior due to the destabilizing characteristics of the CPL. The proposed robust linear controller stabilizes the system and provides output-voltage regulation while accounting for parametric uncertainties. Specifically, the controller synthesis imposes prescribed constraints on closed-loop pole location, control effort, and disturbance attenuation. The controller is evaluated using a switched boost-converter model implemented in PSIM under load-power and input-voltage disturbances. Simulation results show settling times of approximately 2 ms for the load disturbance and 1.5 ms for the input-voltage disturbance, together with improved damping compared with the conventional LQR controller. These simulation results demonstrate the effectiveness of the proposed LMI-based controller in maintaining output-voltage regulation under the evaluated operating conditions.