Analysis on DC System Block Caused by Pole I Pole Busbar DC Voltage Divider Fault of ±500 kV Longquan Converter Station
External insulation of Pole I Pole busbar DC voltage divider flashover happened in Longquan Converter Station on Feb 26th,2009 ,the same affair occured in Jiangling station in 2004. The paper analyses the extenal insulation setting and the reason caused its flashover of this divider,and analyses the operation conditions of other equipments in longquan station and other stations of Three Gorge output project at the same time,coming to the conclusion that it should raise the external insulation design value.