A practical approach to HVDC system control for damping subsynchronous oscillation using the novel eigenvalue analysis program

This paper presents a practical approach for supplementary control of high voltage direct current (HVDC) system to damp subsynchronous oscillation (SSO) involving HVDC converters and turbine- generator shaft systems. A novel eigenvalue analysis (NEA) program, HVDC system modeling to consider steady-state and dynamic conditions in a combined ac/dc system, and an appropriate control scheme have been utilized. The design method proposed facilitates the design of a subsynchronous oscillation damping controller (SODC) to provide positive damping torque for the dominant torsional mode in combined ac/dc systems. The suggested SODC design method has been applied to an ac/dc system to verify its practicality using the EMTDC simulation program.