Huajie, Yi

PhD Student
Project title: Development of a Novel Online Cable Insulation Resistance Measurement Technique

The novel in-service cable insulation resistance measurement is based on the leakage current and dielectric loss. Insulation defects can be identified through Insulation Resistance (IR) or Dielectric Loss (DL/tanĪ“) methods during routine tests. However, these methods can only be carried out when a cable circuit is switched out of service, and measurement is taken under a direct current (DC) supply. The off-line method does not reveal insulation problems which only appear under the conditions prevalent under operational stresses. The challenge of the project remains at the resolution and accuracy of the current sensors to distinguish the tiny leakage current. The dielectric loss angle can be determined by the pulse signal generated from power electronic devices and thus the condition of cable insulation can be determined.