Analysis of corona and surface discharge signals from different non-intrusive sensors


The use of high voltage direct current (HVDC) transmission technology has increased significantly in recent years due to its numerous advantages over traditional alternating current (AC) transmission. The aim of the present work is to investigate the efficiency of different non-intrusive sensors for partial discharge measurement in medium or high voltage direct current equipment such as air or gas insulated switchgear. HV equipment are susceptible to partial discharges such as corona and surface discharges, which can lead to the premature aging of the insulation and its breakdown. The partial discharges appear because of the enhancement of the electric field around sharp edges, triple points, floating metallic particles or in cracks or cavities inside solid insulation. In HVAC systems, partial discharge detection and quantification are well understood. However, under HVDC, there is a necessity to evaluate the efficiency of classic techniques and commercial non-intrusive sensors. This work presents a study of three different sensors for partial discharge measurement under HVDC: high frequency current transformer (HFCT), ultra-high frequency antenna (UHF), and transient earth voltage (TEV). The signals of the different sensors partial discharge detection are presented and compared in both temporal and frequency domains.

Ayyoub Zouaghi, Sneha Satish Hegde, Christian Vollaire, Matthieu Dalstein

Presented at IEEE IAS EPC 2023