Publikasjoner og ansvarsområder
Microscopy Study of Inception Sites of Vented Water Trees in a HV XLPE Cable Aged in Salt Water
Effects of Frequency and Temperature on Partial Discharge Characterization of Stator Windings
A Deterministic Breakdown Model for Dielectric Interfaces Subjected to Tangential Electric Field
The contact area between solid insulations, namely solid-solid interfaces, affect the dielectric characteristics of an entire insulation system. With the theoretical and experimental studies covered in this paper, we intend to investigate the effects of the elastic modulus, interface contact...
In situ synthesis of epoxy nanocomposites with hierarchical surface-modiﬁed SiO2 clusters
Polymer nanocomposites are often produced using in situ approaches where an inorganic ﬁller (as the dispersed phase) is synthesized directly in an organic matrix. Such an approach generally leads to improved dispersion and reduced agglomeration of the ﬁller material. Epoxy-based nanocomposites have...
Partial Discharge Characterisation of Stator Windings Taken from a 50-year-old Norwegian Hydrogenerator
This paper presents results from laboratory measurements of partial discharge (PD) activity in stator bars taken from a 95 MVA hydrogenerator after 52 years in service. The generator has previously been subjected to off-line condition monitoring including partial discharge (PD) testing at both...
Partial Discharge Inception Voltage of Voids Enclosed in Epoxy/Mica versus Voltage Frequency and Temperature
Fault mechanisms of incorrectly installed force springs for ground screen connections in medium voltage cable systems
Time domain dielectric response of field grading sleeves subjected to high humidity and temperatures
It is experienced that MV XLPE cable links including heat shrink cable joints can have a high electrical conductivity compared to the XLPE cable insulation. The field grading sleeve included in the joint design is proposed to be responsible for the reduced insulation resistance and is therefore...
Time Development of Voltage Frequency Dependence of Partial Discharge Activity in Voids
Condition assessment of high voltage equipment based on partial discharge measurements is often performed after a voltage pre-conditioning period. The aim of this paper is to present results from experimental examinations of time variance of partial discharge activity and to propose physical...