Transient Voltage Stability Analysis of East China Receiving-End Power Grid With Multi-Infeed HVDC Transmission Lines

Abstract

Based on the summer peak load operation mode of the planned North China-Central China-East UHV power grid in 2015,there will be 10 HVDC transmission lines feeding into East China power grid.The strength of East China receiving-end power grid is analyzed by short circuit ratio(SCR) and multi-infeed short circuit ratio(MISCR),and the impacts of network topology adjustment in receiving-end power grid and the positions where the multi-infeed DC transmission lines are connected with East China receiving-end power grid on SCR/MISCR are dissected.By use of PSD-BPA transient stability program,transient voltage stability of East China receiving-end power grid under various faults is analyzed.Analysis results show that the positions,where the multi-infeed DC transmission lines are connected with East China receiving-end power grid,greatly impacts the strength of the latter;all unipolar block faults occurred in DC systems,single faults occurred in AC/DC system,three-phase permanent short-circuit fault,which causes the tripout of two circuits,occurred in UHVAC transmission line of receiving-end system and that occurred in the line near commutation buses of inverter station and majority of DC bipolar block faults occurred in DC systems will not lead to transient voltage instability of East China receiving-end power grid;when DC bipolar block faults occurred in UHVDC transmission lines,which are from Jinping to Tongli,Grenoble union of cylinder to Jintan,Fulong to Fengxian and Xiluodu to Zhexi respectively,it is necessary for East China receiving-end power grid to take generator tripping measures or its system stability cannot be maintained.