Modeling of dielectric dissipation factor measurement for XLPE cable based on Davidson-Cole model

摘要

Dielectric response analysis is one approach for the condition assessment of high voltage insulation systems, and measurement of the dissipation factor or tan delta is widely used in practice. This article presents an experimental study of DF measurement over the frequency range from 1 mHz to 50 Hz. Three different short sections of service-aged 11-kV cross-linked polyethylene cable are used as test specimens. Low-voltage polarisation / depolarisation current and frequency domain spectroscopy techniques are employed in the investigation. Following the experimental work, numerical analysis is carried out utilizing the Davidson-Cole (D-C) model. To optimize the final parameters of the model, numerical simulation is performed using 3 or 4 R-C branches with different values of Jonscher and D-C constants. It is shown that results from numerical simulation agree well with the experimental results over the tested frequency range.