Eigenvalue analysis of the stabilizing effects of feedback linearizing control on subsynchronous resonance

Subsynchronous resonance can occur when a series capacitor is used to compensate for the inductance of a high-voltage power transmission line. If the natural frequency of the network is close to the natural modes of the generator shaft subsystem, a resonance can occur which is potentially damaging. A feedback linearizing excitation control for a synchronous generator is evaluated with respect to its effects on an unstable subsynchronous mode. Although the shaft and transmission dynamics are unmodeled for the purpose of the control design, it has been shown via simulation to stabilize and provide significant damping for the resonant mode. Eigenvalue analysis is performed in this paper to corroborate this finding.