Sensitivity Check of Internal Sensor for Power Transformer Partial Discharge Measurements

The UHF partial discharge measurement technique is under research in order to be used for the detection, identification and localization of discharging defects within a power transformer. However, it requires installed dielectric windows on the transformer tank for the placement of the UHF sensors, a feature not available in all transformers especially old ones that have a higher risk of failure. Therefore, it is necessary to develop UHF sensors that can be used in the case of transformers without dielectric windows. In this paper such a sensor in its early design stages is studied, which can be inserted in a transformer from one of its valves.