Comparative Study of PI, PID controller for Buck-Boost Converter tuned by Bio-Inspired Optimization Techniques

In this paper the Buck-Boost converter was modelled using state-space averaging approach and simulated in MATLAB/Simulink. Buck-Boost converter with closed loop control, operated with PI and also with PID controller for good voltage regulation. Bio-inspired optimization techniques e.g. GreyWolves optimization Technique (GWO), Genetic Algorithm(GA), Particle Swarm optimization (PSO), Ant-Lion optimization (ALO), Whale optimization Algorithm (WOA) were used for tuning PI and also PID controller based Buck-Boost Converter. In order to find out the performances of PI and PID in the Buck-Boost converter, comparison between optimal values of PI parameters $(\text{K}_{\text{p}},\ \text{K}_{\text{i}})$ and PID parameters $(\text{K}_{\text{p}},\ \text{K}_{\text{i}},\ \text{K}_{\text{d}})$ obtained by all the above mentioned optimization techniques were performed. The transient behaviour for each optimal values of PI and PID controller was investigated when the system subjected to a load disturbance. Also, for each optimal PI and PID controller error performance indices e.g. Integral Squared Error and Integral Absolute Error were evaluated. The comparison proved that the PID is most suitable controller for Buck-Boost Converter as it is damping out the oscillations caused due to load disturbance 87.56% faster than PI controller. Moreover, based on the evaluated values of error performance indices and dynamic behaviour, it has also been proven that GA is best optimization technique among others for tuning PID in a Buck-Boost Converter.