A Bounded Nonlinear Controller for a Class of Step-Up DC/DC Converters: Application to Renewable Energy Sources

This article presents a novel time derivative-free bounded nonlinear controller (BNLC), including a refined integral action, for a class of boost DC/DC converters. The proposed strategy avoids the complexity of optimization-based methods through an explicit analytical form and mitigates potential noise issues associated with derivative-based controllers. The proposed controller guarantees boundedness via explicit duty cycle limits, with a complete closed-loop stability analysis provided. Validation on an experimental testbed compares the method against advanced proportional integral (PI) and sliding mode plus PI (SMPI) controllers. Results demonstrate superior and consistent transient response across the entire operational range, particularly in highly nonlinear low-current regions where it is 72% faster than robust benchmarks. In addition, it shows significantly higher noise immunity [12–20 dB higher signal-to-noise ratio (SNR)] and robustness under PV shading and large parametric variations.