Effect of HVDC line faults on transient torsional torques of turbine-generator shafts

This paper investigates the effects of HVDC line faults, line de-energization, and line re-energization on the transient torsional stresses of steam turbine-generator (T-G) units. The studies are conducted on a bipole HVDC system which connects a T-G set to a large AC system. The shaft transient stresses of the T-G set as a result of HVAC line fault, fault clearing, and automatic reclosure are also determined when the HVDC transmission system is replaced by an equivalent double-line HVAC system. The EMTDC program is used for the simulation studies