Correlating conductivity and space charge measurements in multi-dielectrics under various electrical and thermal stresses

T.T.N. Vu (1) , G. Teyssedre (2) , Bertrand Vissouvanadin (1) , Séverine Le Roy (2) , Christian Laurent (2)

1 LAPLACE - LAboratoire PLasma et Conversion d'Energie
2 LAPLACE-DSF - Diélectriques Solides et Fiabilité

The design of transmission systems requires electric field distribution estimation, which, in case of HVDC application is strongly sensitive to thermal and electrical configuration as well as to the nature of dielectric materials being used owing to the resistive field distribution. In this paper, the field distribution in a dielectric bilayer of XLPE and rubber materials, as representative of cable junctions, is estimated based on experimental data on field and temperature dependencies of conductivity. Through space charge measurements on bi-layer dielectrics, it is shown that the space charge density and electric field distributions are to a first order estimation consistent with data issued from conductivity measurements. Most notably, the interface charge building up between the two dielectrics changes sign, depending on field and temperature. However, in the high field range (order of 20 kV/mm), charge build-up in the bulk of dielectric materials introduces further distortion to field distribution.

Mots clés: HVDC cable materials; field estimation; interfacial charge

Domaines: Sciences de l'ingénieur [physics]; Matériaux

T.T.N. Vu, G. Teyssedre, Bertrand Vissouvanadin, Séverine Le Roy, Christian Laurent. Correlating conductivity and space charge measurements in multi-dielectrics under various electrical and thermal stresses. IEEE Transactions on Dielectrics and Electrical Insulation, 2015, 22 (1), pp.117-127. ⟨10.1109/TDEI.2014.004507⟩. ⟨hal-03169878⟩