Performance comparison between nonlinear and linear controllers with weighted adaptive control applied to a buck converter using poles placement design

This work presents a comparative study between four control strategies applied to a buck converter: Linear PID, Adaptive nonlinear PID with Gaussian Gain Functions (ANLPID-GGF), Linear Quadratic Regulator (LQR) and (State-dependent Riccati Equation) SDRE. In the case of the buck converter application, SDRE exhibited a better overall performance, but lacks a null error characteristic, typical of a control with an integral component. Taken the converter transfer function, the designs of the four controllers are set so the operating point of the closed loop system presents the same natural frequency. Based on the fore mentioned study, weighted combinations of the controls are proposed and analyzed. In the case, the weighted combination aims to gather the best of a particular control technique in order to achieve better results when compared to a single control technique. The weights are dependent on the error range. Some performance enhancements have been observed. Simulation results of the proposed control schemes are presented.