Discrete-time sliding-mode based digital pulse width modulation control of a boost converter

Identifier:  PC:2707

Handle: https://hdl.handle.net/20.500.11797/PC2707

Authors:  Vidal-Idiarte, E.; Marcos-Pastor, A.; Garcia, G.; Cid-Pastor; Martínez-Salamero, L.

Abstract:
In this work a non -linear digital control of a boost converter based on a sliding discrete-time approximation is presented. The control strategy follows a classical cascade regulation scheme with the inner loop consisting in a non linear current-control based on discrete-time sliding mode, and the outer one being composed of a simple discrete-time PI controller for output voltage regulation. An analytical expression of the current control law is developed using a simplified discrete-time small signal model of the boost converter. The discrete-time PI compensator is designed from a discrete-time small signal parametric model of the inner loop obtained by linearization around the desired equilibrium point. The proposed method is initially based on the notion of discrete-time sliding motion to eventually derive a PWM controlled system. Thus, the reported approach can be categorized not only as a Direct Digital Design technique for voltage regulation but also as a competitive method to design sliding-mode based PWM controllers. Simulated and experimental results in a boost converter operating in continuous conduction mode verify the theoretical predictions.