Abstrato

Improvement of Small Signal Stability of a Single Machine Infinite Bus Using SSSC Equipped With A Hybrid Fuzzy Logic Controller

G. Jeelani Basha ,N. Narasimhulu , P. Malleswara Reddy

In this paper, an attempt has been made to study the application of static synchronous series compensator (SSSC) equipped with a Hybrid Fuzzy Logic Damping Controller (HFLDC) to improve the small signal stability of Single Machine Infinite Bus (SMIB) power system. Small signal stability problems due to low frequency electromechanical oscillations are inherent phenomena of interconnected power systems which reduce the available transfer and total transfer capability. Power system stabilizers (PSS) used for damping these oscillations may not mitigate these oscillations under certain operating conditions, so Flexible AC Transmission System (FACTS) devices deployed in transmission networks can be used by adding a supplementary controller. Such supplementary controllers are often known as Power Oscillation Damping Controllers (PODs). In this paper different methods have been described to design the POD controller for SSSC. This research is carried on a modified Heffron-Phillips model of a single machine infinite bus (SMIB) system integrated with SSSC. In the following a HFLDC for SSSC is well-designed to enhance the transient stability of the power system. In order to evaluate the performance of the proposed HFLDC in damping low frequency oscillations (LFO), the SMIB power system is subjected to a disturbance such as changes in electromechanical power. Digital simulations are performed in the MATLAB/Simulink environment to provide comprehensive understanding of the issue. Simulation studies validate the effective performance of the developed HFLDC in damping electromechanical oscillations in comparison with Fuzzy Logic and the conventional proportional-integral (PI) controller.