Abstract: The power quality resources have continuously played an important role in the growth of human livings. PSO tuned PI controller are compared and a mark reduction in total harmonic reduction is with number of generations. PI Controller distributed Generation units that encompass a portion of an electric power distribution system and may rely on different energy sources. Functionally, the PI controller is required to provide adequate levels and quality of power to meet load demands. The issue of power quality is significant as it directly affects the characteristics of the PI controller operation. This problem can be defined as an occurrence of short to long periods of inadequate or unstable power outputs by the PI controller.