On-line condition monitoring of EHV XLPE oil-filled terminations by using a new sensing system

The ongoing legislative push to mitigate the environmental impact of strong greenhouse gases creates a need for liquid-filled High Voltage (HV) and Extra High Voltage (EHV) terminations. The exceptionally long expected lifetime of many such components requires that on-line condition monitoring is made available to the grid operator. In this paper, we present the design methodology, prototyping and testing of a removable multi-physics sensing unit and a custom, integrated PD sensing unit for HV/EHV liquid-filled terminations. The units were successfully tested in the HV laboratory using a 245 kV oil-filled termination.