Study of DC partial discharge on dielectric surfaces: Mechanism, patterns and similarities to AC

Saliha Abdul Madhar,Armando Rodrigo Mor,Petr Mraz,Rob Ross

doi:10.1016/j.ijepes.2020.106600

Saliha Abdul Madhar, Armando Rodrigo Mor + Show 2 more

Open Access

https://doi.org/10.1016/j.ijepes.2020.106600

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Abstract

This paper presents the investigation on surface discharge behavior of various dielectric samples under DC. It sequentially develops the knowledge base for the study and analysis of the partial discharge (PD) defect with the goal of PD defect identification under DC. In order to facilitate this, the material properties of the dielectric are measured. Finite Element (FEM) simulation is used to obtain the preliminary estimates of the electric field and dielectric properties that concern partial discharge behavior. The DC-PD tests performed on the surface dielectric samples demonstrate a highly plausible behavior based on simulation results and other literature. It also displays a great degree of similarity towards the AC surface discharge behavior. The paper concludes by presenting novel partial discharge fingerprints for the surface PD defect that will aid in defect identification under HVDC.

Highlights

AS the power rating of the transmission network increases and the system moves from high voltage (HV) to extra high voltage (EHV) and ultra-high voltage (UHV), the criticality of the network elements has been increasing
The paper concludes by presenting novel partial discharge fingerprints for the surface PD defect that will aid in defect identification under HVDC
It can be observed that the distribution be comes very similar to the DC pulse sequence analysis (PSA) plots. This verifies the claim made in the beginning of the section that the surface discharge phenomenon in the AC and DC case are not exclusive but share the same underlying discharge process and still remain comparable. This investigation on the surface discharge phenomenon under DC stress is conducted with the final goal of providing tools for defect identification under HVDC

Summary

Introduction

AS the power rating of the transmission network increases and the system moves from high voltage (HV) to extra high voltage (EHV) and ultra-high voltage (UHV), the criticality of the network elements has been increasing This has given rise to an expectation of increased level of reliability when it comes to asset quality. Various other effects such as charge trapping, homo/hetero charge formation at interfaces and irregularities have made the realization of robust DC components a highly sophisticated process [2]. Due to these complexities, the partial discharge behavior of the insulation in the presence of various defects remains highly elusive and distinct from the AC discharge behavior

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