Using Fuzzy PI controller Optimized by PSO for Frequency Control of Island Microgrids

In this paper, the fuzzy proportional- integral controller (PI) optimized by particle swarm algorithm is applied to control the frequency of island Micro-grids. Micro-grids are distributed energy sources that usually use renewable energies in order to produce and transmit electrical power to distributed loads in both connected and islanded modes. Because of natural variations of power that produced by renewable energy sources and uncertainties of power systems, classic controllers do not have a good performance. So nominal values of PI parameters and interval of fuzzy membership functions are optimized using PSO algorithm. Fuzzy system updates PI parameters momently. Simulations show the better performance of proposed controller in terms of RMS, overshoot and undershoot, frequency of oscillations and settling time in facing different load disturbances in comparison to classic PI controller, fuzzy PI controller and another PSO fuzzy controller. Results indicate the robust performance of the proposed controller in dealing with variation of system parameters.