Load Frequency Control of Two-Area Interconnected Power System Using Fuzzy Logic-Based PI Control Method

Load frequency control (LFC) plays an important role to maintain the system frequency and tie-line flow at their respective scheduled values during normal period in the power system. Generally, the conventional control strategies, such as PI and PID control algorithms are applied for LFC in practical power systems. However, good control performance could not be guaranteed by using such traditional control strategies when external disturbances occur. In order to overcome the drawbacks, fuzzy logic-based proportional integral (FLPI) controller is proposed for an efficient LFC performance in this paper. Considering the reason that various disturbances and uncertainty consisting of load variation, modeling error, and structure change exist in power system, fuzzy logic modeling method is used for improving the robust performance. And a PI control strategy based on Ziegler-Nichols is used to eliminate or reduce the frequency deviation, tie-line deviation, and area control error. Finally, simulation results demonstrate that the proposed method can stabilize the two-area power system; the performance indices including settling time and overshoots of the tie-line power and frequency deviations can also be improved through the proposed method.