Abstract:

DC filter is one of the critical devices in HVDC power transmission project. The configuration scheme and parameter selection process of arrester in DC filter were analyzed in-depth, and the specific expression of arrester parameters was presented. Two typical fault conditions which played decisive roles on the insulation level of DC filter were studied: ground fault on DC line and incoming switching surge on DC line； meanwhile the calculation model of these fault conditions were introduced, in which fault inductance between fault point and high-voltage side of DC filter should be considered. Based on the practical ±1 100 kV UHVDC transmission project, the overvoltage of DC filter devices was also calculated. The maximum transient overvoltage of all the DC-filter devices was presented in the calculation result, and then the final insulation level of DC-filter devices in this UHVDC project was determined according to their insulation margin, which could provide the basis for the selection of equipment and manufacturing.

Key words: ±1 100 kV UHV, UHVDC, DC filter, overvoltage, arrester, insulation level