Research on characteristics of large-capacity metal-oxide surge arrester at long-duration current impulse for HVDC converter stations

Arrester is the basis for the insulation coordination. Depending on the installation location of Metal-oxide Surge arrester for HVDC converter stations, there are significant differences in the rated voltage, energy absorption capacity of an arrester. In addition to limiting lightning and switching overvoltage in system, huge energy is also absorted by arresters for HVDC converter stations. DC transfer switch arrester and neutral bus arrester are a kind of typical large-capacity arresters. The energy absorption of large-capacity arrester is much greater and the failure probability of large-capacity arresters is also greater than others for HVDC converter stations. Some experiments of long-duration current impulse were carried out by selfdeveloped test devicer. The voltage and energy withstand of long-duration current impulse versus time characteristic were studied and empirical formula was fitted. The test results show that voltage and energy withstand of long-duration current impulse are going down with the increase of duration. The insufficient energy absorption capacity is the reason for the frequent failure of large-capacity arresters. These conclusions can be used as a reference for the design of arresters for HVDC converter stations.