Improvement of dynamic power system stability by installing UPFC based on Fuzzy Logic Power System Stabilizer (FLPSS)

Low-frequency oscillation is associated with dynamic power system stability. In this paper, the ability of power system to damp low-frequency oscillation is compared between the conventional system with PSS and system installed with Unified Power Flow Controller (UPFC) based on Fuzzy Logic Power System Stabilizer (FLPSS). Both models are developed using linearized model of Phillips-Heffron Single Machine Infinite Bus (SMIB) and simulated in Matlab Simulink. UPFC controller based on boosting modulation index converter (m_b) and excitation modulation index converter (m_e) have been designed using Single in Single Out (SISO) method. The change of rotor speed, rotor angle and electrical power is investigated when power system is being perturbed by small disturbance. The results of this study shown the improvement of dynamic power system stability using the designed model by damping low-frequency oscillation with less overshoot and shorter settling time.