Optimization of PID controller parameters for automatic generation control in two-area heating system using firefly algorithm

Automatic generation control is a vital part of operating and controlling power systems providing adequate and reliable energy with proper quality. Load frequency control is important in large-scale power systems which usually include interconnected control areas, to keep the system frequency and transmit power among areas close to planed values. The mechanical power put into the generators is used to control the frequency of the output electrical power and maintain the transient power among the areas at the planed value. A well-designed power system must be capable of acting well against load changes and perturbations of the system, providing a high level of expected power quality while keeping the frequency in an acceptable range. The problem of automatic frequency setting and crossing power of tie line in power systems dates long back in the history. Various control strategies, often related to the intelligent algorithm applications have been used in the load frequency controller design in recent years. The proportional integral derivative controller has drawn much attention among different types of load frequency controllers. However, recently using intelligent algorithms in optimization problems has occupied a prominent place. In this paper, the firefly algorithm is used to design a PID controller for automatic generation control in a two-area heating power system. The results of this simulation show that the proposed method has achieved a better dynamic performance compared to the PID controller with a degree of freedom in this system. Finally, the dynamic response of the power system under step load changes is investigated by the proposed method and it has been observed that 2-DOF PID controller optimized with the proposed firefly is very effective and it has a good dynamic performance.