Impact Of Parameter Characteristics And Fault Clearing Time In Subsynchronous Resonance

For the north corridor of'West-East Power Transmission Project'in China, the multi-mode SSR (subsynchronous resonance) problem caused by the relatively high compensation level of series capacitor in long-distance high-capacity plant-to-grid transmissions, poses a practical threat to the safety of the turbine-generators and the stability of the grid. On the basis of discussing the mechanism of multi-mode SSR occurrence, this paper analyzes parameter characteristics of SSR caused by Torsional Interaction (TI) and researches impact of relevant important parameters to SSR taking the Shangdu series-compensated transmission project as example. Measures and approaches are proposed to avoid SSR. In addition, aiming at studying the impact of fault clearing time on Shaft Torque Amplification (STA) of SSR, the source of shaft impact torque is firstly investigated and the shaft response to the shaft impact torque is then deduced in detail. The relationship between maximum shaft torque and fault clearing time is finally derived as simulation result demonstrating its validity and applicability. Conclusion helps in choosing a proper fault clearing time to decrease the reduction of shaft life.