Anhydride-free epoxy material for HV insulation


This work proposes a new formulation of anhydride free epoxy composite, for HV AC/DC application. Physico-chemical characterizations were carried out on thermal, dielectric, and tensile properties. The main results are: (i) the anhydride-free formulation EpIL shows an increased glass transition temperature (ΔTg ≈ 25-30 °C at 3 °C.min 1), (ii) an improved thermal conductivity λ = 0,99 W.m 1.K-1, and (iii) an equivalent maximum stress at break (σmax = 45 MPa) in comparison to the reference material. Moreover, at 50 Hz and room temperature, the permittivity and the dielectric losses of the new formulation are alike the reference. Furthermore, from an industrial point of view, the new formulation is suitable for casting, which enables testing on full size samples. Indeed, the pressure resistance tests are still to be performed to confirm mechanical properties as observed during tensile test. An additional feature that may be interesting for this formulation is the increase in the DC conduction at low frequency that may be an asset for DC applications [9;10]. Therefore, the HV electrical properties such as dielectric breakdown, ageing and DC conductivity are under investigation.

Sophie Iglesias, Servane Haller, Antoine Perez, Frank Jacquier, Than Vu-Cong, Alain Girodet, Martin Henriksen

Presented at Insucon 2023