Application of gate-controlled series capacitors (GCSC) for reducing stresses due to sub-synchronous resonance in turbine-generator shaft

The main purpose of this paper is to verify the capability of the gate controlled series capacitor (GCSC) to mitigate subsynchronous resonance (SSR) and electromechanical oscillations that occur when a steam turbine-generator (T-G) is connected to a long transmission line with series compensation. SSR develops the stresses at the coupling of T-G set. This investigation was done based on the IEEE First Benchmark Model. Turn-off pulse generator with zero crossing detectors is used for GCSC. By using turn-off pulse generator capacitive reactance of transmission line can be controlled and hence SSR is mitigated. The Matlab simulink is employed to simulate the effect on stresses of T-G shaft. The simulations results show how the stresses on T-G shaft reduce with the application of GCSC.