Impact of six phase transmission line faults on turbine-generatorshaft torsional torques

摘要

This paper explores the impact of six-phase transmission linenfaults and their subsequent fault clearing and reclosing on thentorsional torques induced in turbine-generator shafts. In this context,ninvestigations have been conducted on a large turbine-generator unitnconnected to a sample power system. The paper presents also a comparisonnbetween the torsional stresses induced in the turbine-generator shaftsnduring these events with their corresponding disturbances of anthree-phase transmission system. The results of these investigations arenpresented in the form of typical time responses as well as parametricnstudies. The EMTP is used for the simulation studies. The studiesnconclude that six-phase transmission line faults generally inducentorsional torques in the turbine-generator shaft whose magnitudes arenrelatively higher than those induced due to transmission line faults inna three-phase system. This conclusion is true for both sustained faultsnand faults followed by clearing and high-speed reclosingnoperations