Frequency Control Analysis Using Modified Fractional Order PID Controller

In a unified power system, frequency oscillations always pose a concern due to the unpredictability of load. These oscillations are typically mitigated by controllers. In this investigation, we projected a unique structure of the controller by modifying FOPID controllers. By utilizing the modified FOPID controller, we can enhance benefits as it offers superior control actions. This approach will assist in keeping the frequency within acceptable bounds during faults or fluctuations in demand within an interconnected power system that incorporates a geothermal power plant (GTPP), a dish-Stirling solar-thermal system (DSTS), and a conventional steam power plant (SPP). Sine-Cosine Optimization (SCO) algorithm is employed to tune the controllers, with ITAE as the evaluative or fitness function. Initially, the system's performance is assessed under a 3% Step Load Perturbation (SLP) in area 1 and compared to conventional PID and FO-PID controllers by examining negative undershoots, settling time, and positive overshoots. In the second case, the system's response is tested by increasing the load in area 1 by 5%, and the results are compared by evaluating the modified FOPID controller's performance against PID and FO-PID controllers, both tuned with the sine-cosine algorithm. The modified FOPID controller demonstrates superior performance over the other controllers. This comprehensive analysis underscores the effectiveness and reliability of the modified FO-PID controller in managing frequency oscillations and maintaining stability in a dynamic unified power system.