Charge accumulation on insulating spacers for HVDC GIS

A capacitive probe measurement that can be used to quantify the charge density on solid insulators is introduced. Studies performed in the development of a +or-125 kV high-voltage DC (HVDC) gas-insulated converter station and +or- 500 kV HVDC switchgear (HVDC-GIS) are reviewed. The properties and mechanisms of surface charging, the optimum design of the spacer and its breakdown characteristics are summarized. Problems associated with capacitive probe measurement of surface charge and a practical solution to obtain the charge distribution on the spacer are presented.<
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