Robust control of buck-boost converter using sliding mode controller

A comprehensive comparative analysis of Sliding Mode Control (SMC) and Proportional-Integral-Derivative (PID) controllers is conducted by this thesis study to determine the optimal strategy for robust control in buck-boost converters. A particular focus is placed on enhancing the performance and reliability of these converters, which are recognized as crucial elements in several industries, including renewable energy systems, electric vehicles, and variable-speed drives. Due to an ever-increasing demand for higher efficiency and reliability in these applications, a critical need for control systems that can effectively manage uncertainties, parameter variations, and external disturbances without compromising on performance is identified. In response to this need, the theoretical foundations and mechanisms underlying both SMC and PID controllers are first examined by the study. SMC is renowned for its robustness against system uncertainties and disturbances. The operation of this controller in two phases, the reaching phase and the sliding phase, is studied, ensuring that stability is maintained and the desired output is followed even under challenging conditions. On the other hand, the use of a three-component strategy—proportional, integral, and derivative by PID controllers, which are traditionally favored in industrial applications, is analyzed. These controllers are found to often suffer from performance degradation when subjected to uncertainties and parameter variations. The construction and assessment of a sliding mode controller that can be robust against these challenges is aimed for by the study. This construction is benchmarked against a well-tuned PID controller, traditionally considered the choice in industrial applications. Designing, modeling, and tuning of both controllers to specific performance criteria are then undertaken. Subsequently, an evaluation of the controllers based on a series of performance indices that include stability, robustness, dynamic responsiveness, tracking precision, and disturbance rejection capacity is performed by the study. Support for the theoretical evaluations is provided by mathematical proofs and simulation models, establishing the grounds for experimental validation. The strengths and weaknesses of both SMC and PID controllers is achieved by the results. Superior robustness and disturbance rejection are demonstrated by SMC but complexities in design and tuning may be involved. PID controllers, although easier to implement, are shown to have limitations in effectively handling uncertainties and parameter variations.