Water cycle algorithm-based load frequency controller for interconnected power systems comprising non-linearity

• Published in: IET generation, transmission & distribution Vol. 10; no. 15; pp. 3950 - 3961
• Main Authors: El-Hameed, Mohammed A, El-Fergany, Attia A
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 17.11.2016
• Subjects: Algorithms; constrained optimisation problem; Controllers; disturbed load conditions; frequency control; load frequency controller; load regulation; multiarea interconnected power systems; nonlinear control systems; Nonlinearity; objective function; optimal control; Optimization; Parameter robustness; Parameters; PID optimal fine tuning; power system interconnection; Proportional integral derivative; proportional‐integral‐derivative optimal fine tuning; random step load perturbations; sensitivity analysis; three‐term control; time‐domain analysis; time‐domain dynamic performances; Tuning; water cycle algorithm; WCA‐based LFC; WCA‐based PID controllers; three-term control; PID optimal fine tuning; time-domain dynamic performances; sensitivity analysis; proportional-integral-derivative optimal fine tuning; WCA-based PID controllers; constrained optimisation problem; random step load perturbations; time-domain analysis; optimal control; disturbed load conditions; frequency control; load frequency controller; power system interconnection; nonlinear control systems; water cycle algorithm; multiarea interconnected power systems; load regulation; objective function; WCA-based LFC
• ISSN: 1751-8687; 1751-8695
• DOI: 10.1049/iet-gtd.2016.0699

This study addresses proportional–integral–derivative (PID) optimal fine tuning of load frequency controllers for multi-area interconnected power systems. For realistic study, generation rate constraints are considered to increase system non-linearity. The proposed method is applied to equal and unequal multi-area interconnected power systems. A methodology based on water cycle algorithm (WCA) is proposed. WCA is applied to generate optimal fine settings for the four parameters of the PID. A constrained optimisation problem with relevant integral of time multiplied by summation of absolute errors as an objective function is established. The time-domain dynamic performances using the generated optimal PID parameters are demonstrated under disturbed load conditions. At this moment, to show the robustness of the cropped optimised PID parameters, sensitivity analysis under uncertainty conditions is made by varying the system parameters from their nominal values. Specifications of time-domain dynamic performances are compared with other competing and Ziegler–Nichols PID tuning techniques which attest the significance of the proposed WCA-based LFC. Finally, the proposed WCA-based PID controllers are verified against random step load perturbations with different sampling times.