Nonlinear PI and Finite-time Control for DC-DC Converter Based on Exact Feedback Linearization

Based on differential geometry theory, a nonlinear PI and global finite-time controller (PI+FTC) under exact feedback linearization (EFL) is proposed in this paper. Firstly, the coordinate transformation equation is derived by the affine nonlinear model of the buck converter, and the Brunovsky canonical form of the buck converter is obtained. Then, according to the canonical form, PI+FTC is designed. Furthermore, the Lyapunov stability principle is applied to prove that the control strategy is stable. Finally, the results of simulation and experiment indicate that the proposed method has a shorter setting time and stronger robustness than the linear PI controller when the input voltage and load are disturbed. The proposed control strategy realizes time optimal control and is also applicable for the stabilization of other dc-dc converters.