Applying TCSC frequency response data derived using electromagnetic transient analysis in SSR frequency scanning studies

The traditional SSR frequency scanning technique can be generally considered as the most practical and straightforward approach to study the possible instabilities concerning torsional oscillations. However, as the number of controllable and highly nonlinear power system components is continuously increasing, their contribution to the frequency response characteristics of a power system will become more significant. Therefore, the traditional SSR frequency scanning technique can more often be found insufficient for modeling the torsional oscillation related characteristics of a power system with reasonable accuracy. In this paper approach for determination of the frequency dependent response of the thyristor controlled series capacitor (TCSC) to torsional oscillations is presented utilizing the generic signal injection approach. After analysis of the frequency dependent response characteristics of the TCSC with different study approaches suitability of the determined frequency response data in a SSR frequency scanning study is illustrated and analyzed. Finally, the possible benefits and limitations of different approaches to model the frequency dependent response characteristics of the TCSC for SSR frequency scanning purposes are discussed briefly.