A feedback control design of buck converter: An artificial immune system based approach

This article presents design of a Proportional-Integral-Derivative (PID) control for a buck converter by incorporating the principles derived from the processes of Artificial Immune System present in vertebrates in the control design algorithm. The buck converter represents a class of variable structure systems and its controller design by conventional means yields a near-satisfactory performance, however not the best transient and steady state dynamics at wider range of operating points. Therefore a feedback control design problem of buck converter is rearranged as an optimization goal and the concern parameters of the PID controller are found through an intelligent Artificial Immune System (AIS) based technique. Computations have been done by using Matlab software. The output voltage response of buck converter is tested for 1.) reference voltage change, 2.) load resistance change and 3.) input voltage change. To verify the findings obtained in simulations, a prototype of buck converter is build and controlled in the laboratory with the proposed methodology. The results found are then evaluated against the performance of conventional controller design and genetic algorithm (GA) based approach, followed by tabulation of performance measures, which clearly indicates that the AIS method of PID controller design provides better static and dynamic response in the output voltage besides achieving a faster convergence of parameters, thereby confirming the validity of new approach.