Evaluating the effect of subsynchronous oscillation on turbine generator shaft

As HVDC and series capacitor compensation transmission lines are widely used, subsynchronous oscillation (SSO) problem stands out. Evaluating the effect of subsynchronous oscillation on shaft system is the foundation for ensuring turbine-generator unit security. The mechanism of shaft damage was analyzed from material mechanics point of view in this paper, and the method for evaluating the effect of SSO on shaft system was put forward. Firstly, variational-amplitude SSO was transformed into a series of constant-amplitude SSO using rain flow algorithm. Then, the fatigue damnification of shaft system resulting from SSO was calculated according to Miner rule. The validity of the evaluation method about the effect of SSO on turbine generator shaft was shown through the subsynchronous resonance of IEEE first benchmark model.