The characterization of a LDPE affected by different levels of water tree degradation using absorption current measurements

Dielectric characterization and conduction modelling of a water tree degraded LDPE

“…which means that we get expressions that directly connect the microscopic/macroscopic variables of our LDPE sample with the actual values of our measured experimental current parameters {I 0 ,m} [34]. Moreover, we will be able to discuss the evolutions of the parameters (Curie-von Schweidler law) with the variations of polarization voltage and water tree degradation, as we will see later on.…”

“…The related permittivity values are taken from real permittivity measurements performed on polyethylene specimens degraded by water trees [34,4]. We also took into account for our calculations the relationship between the macroscopic variable relative permittivity, ε r , and the microscopic parameter b=np 2 ,…”

Effect of annealing on conductivity in XLPE mid-voltage cable insulation

“…It is well known that reliable measuring of high impedance insulation requires very careful guarding and shielding of the measured object. This is of particular importance when measuring small samples [26] or short cables [27]. One metallic ring on each side of the outer electrode, 2 mm aside of the latter, were used as guard electrode in order to avoid the effect of surface conductivity and to avoid the dispersion of the field lines.…”

A new approach to the modelling of the conduction processes in a water tree degraded LDPE

“…(ii) z, = Sa,P,z" = sa, S z " RTL which means that we get expressions that directly connect the microscopic/macroscopic variables of our LDPE sample with the actual values of our measured experimental current parameters {Io,m} [6].…”