Study of Surface Resistivity of an Epoxy/Gas Interface versus Electric Field and Relative Humidity

Rachelle. Hanna (1) , Olivier Lesaint (1) , Olivier Gallot-Lavallée (1) , Laetitia Zavattoni (2, 1)

1 G2ELab - Laboratoire de Génie Electrique de Grenoble
2 Siemens

Surface resistivity of solid insulators is usually determined by measuring the current induced when an electric field tangential to the surface is applied. This classical method can become questionable when the electric field is raised. In fact, a current may also flow above the interface through the humid gas, in addition to currents flowing at the interface and below the interface within the solid bulk. This paper presents an experimental study of the variation of the surface resistivity versus electric field and relative humidity RH of the surrounding gas. The results show that in dry gas (RH < 1%) and for an electric field up 8 kV/mm, the surface gets no specific properties compared to the volume. However, in humid gas (1% < RH < 10%), a decrease of the net surface resistivity (by subtracting the current above and below the interface) is detected.

Domaines: Energie électrique

Rachelle. Hanna, Olivier Lesaint, Olivier Gallot-Lavallée, Laetitia Zavattoni. Study of Surface Resistivity of an Epoxy/Gas Interface versus Electric Field and Relative Humidity. ICD 2016, Jul 2016, Montpellier, France. ⟨hal-01343453⟩