Electromechanical Oscillations Damping Using Differential Evolution Design Based Power System Stabilizer

This research work deals with the reduction of electromechanical oscillations inherent in any power system by adding a properly designed Power System Stabilizer (PSS). The conventional design of PSS is the classical Lead-Lag (LL) compensator. Proportional-Integral-Derivative (PID) has been proposed in the literature because of its simplicity, robustness, and ability to eliminate the steady-state error. In this paper, a PSS with a PID structure is designed using Differential Evolution (DE) technique. An approximate tuning of the PID is usually done using Ziegler-Nichols (ZN) technique. To show the effectiveness of the PID design using Differential Evolution (DE) over Lead Lag (LL) and Ziegler Nichols ZN, DE based PSS is added to the automatic voltage regulator to drive the power system composed of a single generator connected to an infinite bus via a transmission line. Performance evaluation is done through regulation and tracking of the reference values whereas the robustness is evaluated via parameters change namely, the inertia coefficient and the d-axis transient open-circuit time constant. For more realistic results, a nonlinear test was performed where a threephase short-circuit fault at the terminals of the generator was applied. Results are very encouraging to pursue further study.