Constrained model-based predictive controller for a high-frequency low-power DC-DC buck converter

Abstract

This paper describes a very detailed and comprehensive description of a model predictive controller (MPC) applied to the buck converter working in Continuous Conduction Mode (CCM) to optimize the performance of the converter. The converter is designed for a fixed switching frequency of 1 MHz. The proposed model predictive control technique achieves improved set point tracking with minimal overshoot, offers consistent closed loop performance and has short settling time. Although MPC rejects unmeasured disturbances effectively, but it shows poor load and line regulation. Solution has been suggested in order to robustify the load and line regulation. Further neural network based MPC has also been designed. The impact of the MPC parameters such as prediction and control horizons, performance weights, and constraints on the performance is minutely observed. In order to investigate the effectiveness of the proposed algorithms, MPC is compared with the classical well-known PWM-PID controller. MATLAB/Simulink simulation results validate the control design procedure.