A comparison among PID, Sliding Mode and internal model control for a buck converter

DC-DC converters lie at the heart of power electronic systems, finding usage in popular applications like Switched Mode Power Supplies (SMPS). Such demanding applications invariably require constant voltage irrespective of any changes on the load or input side. The un-modeled dynamics and external/internal disturbances make this objective even more challenging. This puts strict restrictions on the design of controllers and opens up avenues for research in this domain. In this paper, three control algorithms have been implemented to achieve better voltage regulation for buck converter. Classical PID controller is compared with Sliding Mode Controller (SMC) and Internal Model Controller (IMC). The converter response with these control archetypes has been compared under supply voltage variations, load changes and parametric variations. Internal Model Control emerges as a superior controller amongst the considered control algorithms with fast response and excellent steady state characteristics. Simulation results establish that Internal Model based controller is able to reject wide range parametric disturbances with negligible deterioration of output.