Fuzzy PID Controller Design for LFC in Electric Power Systems

In this paper, a methodology using Differential Evolution algorithm is proposed for the definition of the discourse universe of the fuzzy PID controller structure variables, for the load/frequency control in power systems, with this eliminating the need of the expert in systems speed control of hydraulic turbines. This controller uses the fuzzy system to tune the PID controller in real time. A mathematical model, based upon constructive information and where nonlinearities are taken into account, of a hydroelectric plant belonging to the Brazilian Interconnected System is presented as a test benchmark to analysis the proposed controller performance under various loading conditions. Simulation results are introduced to show the performance of the developed controller in comparison with a PID controller tuned by a Differential Evolution Algorithm and with a PID algorithm similar to the one actually used in the field. These results denote that the proposed controller offer better performance over others in terms of settling times and oscillation of the frequency.