Open AccessDiagnostic aspects of partial discharge measurement at very low frequency: a review
Author(s) -
Morsalin Sayidul,
Das Narottam
Publication year - 2020
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/iet-smt.2020.0225
Subject(s) - partial discharge , voltage , very low frequency , electrical engineering , corona discharge , materials science , high voltage , low frequency , insulation system , acoustics , computer science , physics , engineering , telecommunications
Electrical insulation of high voltage (HV) power equipment/apparatus plays very important roles in the sound functioning of power systems. Examining the insulation condition through partial discharge (PD) measurements has considerable importance as the presence of PDs in any HV systems stands for a sign of defects and degradations in electrical insulation. Generally, the PD measurements are performed with a supply voltage of normal power frequency (PF‐50/60 Hz). As an attractive alternative, the PD measurement with a very low frequency (VLF–1 Hz or lower) applied voltage has emerged as a powerful diagnostic tool. A PD event is a random physical process, it depends mostly on the availability of free electrons that triggers the PD and the presence of space charge usually originated after a discharge. As the discharge characteristics vary with the supply voltage frequency; thus, the existing interpretation knowledge at 50 Hz may or may not be directly applicable to other test frequencies, particularly in the VLF range. Therefore, to provide a general insight, this paper presents various diagnostic aspects of PD measurements, and at the end, various discharge sources (e.g., void, surface, and corona) and their behaviours under varying the test voltage frequencies are discussed in detail.