Design of PI controllers by using bacterial foraging strategy to control frequency for distributed generation

In this paper a hybrid distributed generation (DG) system connected to isolated load is studied. The DG system consisting of photo voltaic (PV) system, fuel cells, aqua electrolyzer, diesel engine generator and a battery energy storage system. The ambient temperature value of PV is taken as constant to make the output power of PV is directly proportional to the radiation and output power of other DG sources and frequency of the system is controlled by simple proportional plus integral (PI) controllers. A maiden attempt is made to apply a more recent and powerful optimization technique named as bacterial foraging technique for optimization of PI controllers gains of the proposed hybrid DG system. The system responses with bacterial foraging based PI controller are compared with that of classical method. Investigations reveal that bacterial foraging based PI controller gives better responses than the classical method. Sensitivity analysis is carried out which demonstrates the robustness of the optimized gain values for system loading condition.