Application of Subsynchronous Oscillation Relay-Type SSO

A subsynchronous resonance relay which will protect against Torsional Interaction, Torque Amplification, and Induction Generator Effect has recently been developed. This paper describes the theory and rationale applied to select the appropriate settings for the newly developed relay. An example is employed to effectively demonstrate the methods applied. This example in conjunction with a description of some tests provides a good indication of the level of protection and security provided by the relay. Ref. I describes the newly developed relay in detail.