Abstract:
Modern power systems consist of several generators working synchronously to meet the power demand. For
reliability of these systems, stability must be ensured incase of faults within the system. Faults within a system
induce electromechanical oscillations of the electrical generators. These oscillations, also called power swings,
must be effectively damped to maintain the system stability. In an attempt to reduce system oscillations, Power
System Stabilizers (PSS) are used to add damping by controlling the excitation system. Studies have shown that a
well-tuned PSS can effectively improve power system dynamic stability. The paper demonstrates how the Fuzzy
Logic Controller can be used to fine tune the PSS and thus improve the overall stability of a power system.
Simulations have been carried out on 16 bus test system found in literature. The model was simulated in a
MATLAB/SIMULINK environment. A comparison is carried out on a generator without a PSS, with a PSS and with a
PSS plus a Fuzzy Logic Controller. The results indicate that the inclusion of a Fuzzy Logic Controller improves the
damping of electromechanical oscillations introduced by a three phase fault in the system, and hence improves the
overall stability of the system.
