Discrete-time modeling and control of a boost converter by means of a variational integrator and sliding modes

This work deals with the discrete-time modeling of a boost DC-to-DC power converter by means of a discrete Lagrangian formulation based on the midpoint rule integration method. Then in the basis of this model, a discrete-time sliding mode regulator is designed in order to force the boost circuit to track a DC-biased sinusoidal signal. Simulations and experimental tests are carried on where the great performance of the proposed methodology is verified. © 2013 The Franklin Institute. Published by Elsevier Ltd. All rights reserved

An approach to design of digital sliding mode control for DC-DC converters

The primary goal of research in this Ph.D. dissertation is to investigate the possibilities of application of modern control methods in controlling the output voltage of the DC-DC converters (buck, boost) in order to ensure the system robustness to the input voltage and load variations. This dissertation deals with the analysis and application of sliding mode control algorithms in the synthesis of these converters in order to improve the properties of existing converters and to modify them, as well as to adjust and tune the digital sliding mode controls based on the input-output plant model to be applicable in these converters. The design procedure is based on the converter models given in the form of discrete transfer functions. The proposed control for converters is a combination of the digital sliding mode control and (generalized) minimum variance control techniques. The problem caused by an unstable zero of the boost converter, which prevents the direct control of the output voltage of this converter, has been overcome by introducing the generalized minimum variance control. Also, only the output voltage of converter must be measured for the realization of the proposed control, so there is no need for an additional current sensor. This dissertation includes the modification of the developed algorithms with the aim of applying them to low-cost, standard 8- bit microcontrollers. Finally, the efficiency of the proposed solutions is verified by digital simulation and a series of experiments on the laboratory developed prototypes of both converters, as well as by their comparative analysis. The satisfactory experimental results are obtained regarding the typical characteristics of the converters