Low frequency oscillations damping by static synchronous series compensator equipped with an auxiliary fuzzy logic controller

Low frequency oscillations (LFO) are a frequent adverse phenomenon which increase the risk of instability for the power system and thus reduce the total and available transfer capability (TTC and ATC). This brief investigates the damping performance of the static synchronous series compensator (SSSC) equipped with an auxiliary fuzzy logic controller (FLC). At the outset, a modified Heffron-Phillips model of a single machine infinite bus (SMIB) system installed with SSSC is established. In the following an auxiliary FLC for SSSC is well-designed to enhance the transient stability of the power system. In order to evaluate the performance of the proposed FLC in damping LFO, the SMIB power system is subjected to a disturbance such as changes in mechanical power. The complete digital simulations are performed in the MATLAB/Simulink environment to provide comprehensive understanding of the issue. Simulation results demonstrate that the developed FLC would be more effective in damping electromechanical oscillations in comparison with the conventional proportional-integral (PI) controller.