Eigen analysis of series compensation schemes reducing the potential of subsynchronous resonance

A.A. Edris (see ibid., vol.5, no.1, p.219-36, 1990) described a new concept for mitigation of the phenomenon of subsynchronous resonance (SSR) based on asymmetrical series capacitor compensation at SSR frequencies. The studies reported by A.A. Edris are based on a digital time-domain simulation technique. This paper provides a quantitative evaluation of the concept using a novel eigen analysis approach. The eigen analysis approach represents the mathematical models of power system components in the three-phase basis, and can evaluate the impacts of asymmetry and imbalance on the system dynamics in the subsynchronous frequency range. The study results restate the technical feasibility of the proposed SSR countermeasure. This paper opens the avenue for examination of active power filter topologies to introduce artificial asymmetry at SSR frequencies to counteract torsional oscillations.>