Effect of HVDC converter station faults on turbine-generator shaft torsional torques

This paper explores the impact of HVDC converter station faults on the torsional torques induced in turbine-generator shafts. In this context, investigations have been conducted on a large turbine-generator unit connected to an HVDC system. Faults considered are firethrough, misfire and a short-circuit across a nonconducting valve. The effect of the fault incidence time on the maximum turbine-generator torsional torques is also investigated. The results of these investigations are presented in the form of typical time responses as well as parametric studies