This paper presents an application of layered artificial neural network (ANN) controller to study automatic generation control (A GC) problem of a four-area interconnected power system in which three areas include steam turbines and the other area includes a hydro turbine, and all of the areas include superconducting magnetic energy storage(SMES) units. In the study, back propagation-through-time algorithm is used to cope with the non-linear dynamics. As the system equations are satisfactory, no ANN emulator is used. The performance of the power system is simulated by using conventional integral controllers and ANN controller. By comparing the results of simulations, the performance of the ANN controller is better than conventional controllers.