Innovative insulation materials for high thermal and electrical stress

ThermaVolt AR electrical insulating paper ThermaVolt AR (TVAR) electrical insulating paper from 3MTM combines the best of inorganic and aramid technologies. Inorganic insulation provides excellent...

byDr. Mueller


ThermaVolt AR electrical insulating paper

ThermaVolt AR (TVAR) electrical insulating paper from 3MTM combines the best of inorganic and aramid technologies. Inorganic insulation provides excellent thermal conductivity and voltage endurance, while aramid insulation features strong mechanical and thermal properties. With good mechanical strength, particularly the tensile and tear strength, TVAR paper maintains its integrity while remaining conformable.

Made with inorganic material, TVAR insulating paper has higher thermal conductivity than meta-aramid-based insulation, which can enable the improvement of coil performance. As an example, an existing coil design may have a lower temperature rise at the same power level, or the coil load may be increased while the temperature rise is held constant. If the coil design is optimized for higher thermal conductivity, this may result in smaller conductor size and lower overall material cost; and potentially higher efficiency, depending upon the coil design.

TVAR paper can meet some of the most demanding applications with minimal environmental and human impact. It is RoHS & REACH compliant, and it has also earned the HL3 rating, the most stringent in EN 45545-2, which is the standard for fire safety requirements for electrical equipment on railway vehicles.

Applications

TVAR can be used in open-ventilated dry-type transformers rated through class 220 °C (R) as: major and minor ground insulation, core wrap, high-low barrier, inter-winding and turn insulation, and phase insulation.

Thermal conductivity

Enhanced cooling of conductors is required in today’s high-efficiency transformers. TVAR paper has excellent thermal conductivity performance, Table 2, which enables a transformer that has been designed with calendered meta-aramid to run cooler, or if the transformer is redesigned, to potentially reduce size, utilizing less conductor, resulting in lower total transformer cost.

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