Research about Subsynchronous Oscillation Caused by High-Voltage-Direct-Current

Abstract

Torsional interaction exists between HVDC converters and turbine-generators, and negative electrical damping provided by HVDC may cause subsynchronous oscillation (SSO) that can lead to turbine-generator shaft failure and electrical instability at oscillation frequencies lower than the fundamental system frequency. This paper makes a preliminary inquiry about the subsynchronous oscillation mechanism caused by the HVDC system, and puts forward Subsynchronous Damping Controller, and eventually makes a damping synchronous oscillation of the electrical Damping torque increment out of the generator electromagnetic torque to suppressing SSO.