Frequency control is becoming increasingly critical today due to the growing size and changing structure of complex interconnected power networks. Scaling up economic pressures for efficiency and reliability of the power system has necessitated a requirement for maintaining system frequency, and tie-line power flows as close as possible to scheduled values. High-frequency deviations may degrade load performance, damage equipment, resulting in overloading of transmission lines, which may interfere with system protection schemes, and, finally, may also result in an unstable condition of the power system. More so, Load Frequency Control ( LFC) plays a vital role in the modern power system as an auxiliary service to support power exchanges and, at the same time, to provide better conditions for the trading of electricity. Therefore, the tuning of the dynamic controller (i.e., net frequency and net power interchange errors) is a significant factor in achieving optimum LFC performance. Appropriate tuning of the controller parameters is required in order to achieve excellent control action. In view of this, this paper introduces the dynamic tuning of controller parameters in a two-area multi-source power system with an AC-DC parallel tie line for optimum load-frequency control performance. Matlab/Simulink software is used to realize the system simulation. System dynamic performance is observed for conventional PID tuning by the Ziegler Nichols method and the Kitamori method, fuzzy logic controllers, fuzzy-logic PID controllers, fuzzy PID controllers, and polar-Fuzzy controllers. Furthermore, the frequency and tie-line power response of the interconnected areas were compared based on the setting-time, peak-overshoot, and peak-undershoot. The simulation results show that the responses of the fuzzy-based controllers are faster than those of the classical controllers, resulting in minimized frequency and tie-line power deviations.
Applying metaheuristic optimization methods to design novel adaptive PI-type fuzzy logic controllers for load-frequency control in a large-scale power grid
