Subsynchronous resonance in meshed networks with HVDC lines

Abstract

This paper presents a comparison of torsional torques in the shafts of multi stage steam turbines in meshed AC networks, as well as, in networks that employ HVDC lines in parallel to existing AC transmission corridors. A full multi stage turbine model, a four machine meshed AC system and a HVDC system have been developed in DigSilent. The mechanical parameters of turbine-generator shaft system are modeled using probability density functions in order to assess more realistically the risk of rise of sub synchronous resonance (SSR) in meshed networks with HVDC lines.