Finite-Time Parameter Observer-Based Sliding Mode Control for a DC/DC Boost Converter with Constant Power Loads

Abstract

Constant power loads have negative impedance characteristics, which reduce the damping of DC/DC converter systems and have negative effects on the stability of the DC microgrid. In this paper, a finite-time parameter observer-based sliding mode controller is proposed for a boost converter with constant power loads. Firstly, a non-singular terminal sliding-mode controller is designed based on the flatness of the differential and sliding mode control theory. Secondly, a finite-time observer is designed to estimate the input voltage and tunes the parameter of the controller in time. Thirdly, the finite-time stability of the closed-loop system is proved through the proposed controller. Finally, the effectiveness and robustness of the proposed controller with unknown input voltage are verified by simulation. The proposed controller can guarantee finite-time convergence without input voltage sensors, which can reduce system cost and improve system reliability.