Fast development of FACTS, HVDC and renewable generation introduce bigger torsional vibration threats to the turbine-generator shaft system, including: 1）Sub-synchronous Resonance caused by series capacitor compensated transmission lines 2）Sub-synchronous Oscillation caused by HVDC transmission lines 3）Sub-synchronous Oscillation caused by renewable generation interconnections SSO/SSR mainly damages the shaft of turbine-generator due to torsional stress, leads to fatigue expenditure even serious damage, threatens safe operation of the generator and power grid.
It is applicable for large thermal power turbo-generator.
