Influence of AC fault at sending end on receiving-end networks of large-scale AC/DC hybrid power grid

Abstract

In order to meet the need for large-scale transmission of new energy consumption across regions， China has built and put into operation several conventional DC， UHVDC and flexible DC transmission projects and has realized asynchronous interconnection between large power grids and formed a complex large-scale AC-DC hybrid system. Based on the recent fault cases， the paper analyzes the impact of AC/DC hybrid system fault on DC system transmission power and AC voltage at the receiving end， as well as the causes of DC filter tripping at the receiving end and commutation failure at the adjacent DC receiving ends. Moreover， the paper indicates that there exist such problems as dense DC points at receiving end， larger gound capacity of AC filters and poor commutation failure prediction. Finally， it proposes solutions， providing references for future AC-DC hybrid power grid development and construction.

Keywords

• ac/dc hybrid power grid
• fault characteristics
• interaction mechanism
• interlock failure