Determine the compatibility between electrical insulation fluids and solid materials using a micro-calorimeter

Compatibility between solid and liquid electrical insulation materials has been studied using an isothermal microcalorimeter. This work compares the micro-calorimeter measurements with a simple volume and mass increase for the solid material also capable of indicating incompatibility and compatibility in some cases. The measurements reported here on a known incompatible system (XLPE and mineral oil) and a compatible system (XLPE and silicone oil) illustrate how such measurements could be performed. For these materials we conclude that a micro-calorimeter can be used to characterise compatible/incompatible phenomena for electrical material combinations. It proves to be a fast and alternative method potentially capable of screening compatibility between many different material combinations giving an indication/warning of undesirable reactions. Such a methodology must in general be supported by results from other kind of analytical measurements in addition. It could however be used as a first screening method targeting potential promising new material combinations for electrical apparatuses. The most promising material combinations found from such measurements then could later be investigated further with other methods.