The performance of polyurethane foam at different humidity and temperature conditions for high voltage insulation

The active parts of many hollow insulation systems are placed in SF6 or N-2 filled insulating structures. The challenge with using these insulating gases initiated the replacement of them with polyurethane foam, which is frequently used in lowvoltage switchgears. Rigid pour polyurethane foam is presented to serve as a high voltage insulation material. The electrical properties are studied under power frequency and lightning impulse voltage. The performance of the proposed foam is determined at different humidity and temperature conditions.