Computing the damping of subsynchronous oscillations due to a thyristor controlled series capacitor

we extend eigenvalue analysis of SubSWchronous resonance (SSR) to include thyristor switchin@. The eigenvalue computation takes account of the time variations and nonlinearities of both the thyristor switchings and the generator. An example is Presented using the IEEE first benchmark SSR n~&l. The Paper contributes an accurate method to compute the damping of the SSR modes with a TCSC.