Design of Transmission Line and Electromagnetic Field Sensors for DC Partial Discharge Analysis

TL;DR

This paper presents a testbed with specialized sensors and transmission line setup for analyzing DC partial discharge pulses, enabling accurate measurement of electromagnetic fields and discharge currents.

Contribution

It introduces a novel testbed with electromagnetic sensors (D-dot and B-dot) for detailed analysis of DC partial discharges, including calibration and validation methods.

Findings

Close agreement between EM sensor measurements and oscilloscope data.

Effective calibration of D-dot and B-dot sensors for DC PD analysis.

Demonstrated capability to analyze DC cavity discharges accurately.

Abstract

Accurate measurement circuit and high-frequency sensors with sufficient bandwidth are necessary for the analysis of individual partial discharge (PD) pulses. In this paper, a testbed is designed and constructed for the investigation of DC PD pulses. The testbed is equipped with a 50 ohm transmission line (TL) that terminate to an oscilloscope for measuring the charge displacement current generated by PD pulses. Besides the oscilloscope measurements, two types of electromagnetic field sensors (D-dot and B-dot) were developed to capture the EM fields of the PD pulses propagating through the TL. The main goal of this paper is to investigate the DC PD pulses through the EM fields and the corresponding discharge current pulses that are considered as calibrating signals for the developed D-dot and B-dot sensors. The results of DC cavity discharge measured by the constructed testbed and the EM field sensors demonstrate close agreement with the reference PD pulses measured via oscilloscope.