The influence of atmospheric pressure on the space charge of multilayered epoxy: a study using the thermal step method and the thermally stimulated discharge currents technique

In this paper, the authors study the part played by the atmospheric pressure upon the space charge of a multilayered epoxy used in power electronics. The samples were then subjected to high electric fields (7.3 kV/mm) at -30°C, 25°C and 125°C with 27 mbar, 400 mbar, 1 bar atmospheric pressure. Periodically, space charge measurements were made using the thermal step method. The measurements were correlated with thermally stimulated discharge currents experiments, which give the energy levels and the density of the traps. The results prove that the atmospheric pressure acts on the space charge amplitude (whatever the temperature may be -30°C, 25°C or 125°C)