Mitigation of Subsynchronous Resonance Torsional Torque Oscillations via Interval Type-2 Fuzzy Control Based Rectifier Controlled Braking Resistor
M. Fayez Ahmed, M. Mandor, M. A. El-Hadidy, F. Bendary |Pages: 133-148|

Abstract— Implementation of series capacitor compensation of long transmission corridors has been long identified as posing a potential hazard to the steam turbine-generators after the unfortunate two Mohave shaft damage accidents back in the seventies due to the subsynchronous resonance (SSR) phenomenon. The dynamic braking resistor is an extremely functional, simple, and relatively inexpensive SSR mitigation candidate. The dynamic braking resistor linked to the electric grid via high-power thyristors is considered as a special purpose FACTS controller. A new brake model, namely rectifier controlled braking resistor (RCBR), has been recently proposed for enhancing the transient stability in electric power systems. RCBR controlled via Interval Type-2 fuzzy logic controller (IT2FLC) is suggested in this article for tempering SSR torsional torque oscillations. A control signal synthesized from the generator mass speed is utilized in this work as a local control input signal to the IT2FLC to orchestrate the switching strategy of the installed RCBR. For demonstrating the effectiveness of the proposed scheme, a non-linear time-domain simulation study is performed on the well-known IEEE second benchmark test system via MATLAB/Simulink-based modeling and simulation environment. Comparative simulation studies of the test system after being subjected to three-phase to ground fault condition should demonstrate the effectuality of the proposed system for the mitigation of SSR torsional torque oscillations.