Anisotropic Thermal Conductivity of Lamination Stacks of Non-oriented Electrical Steel

Abstract

Heat transfer properties of lamination stacks of the non-oriented electrical steels which important for heat management of high-performance motor core, were investigated. The thermal conductivity of in-plane direction of lamination stack almost coincided with the value which was estimated from the electrical resistance of the steel. The thermal conductivity of through-stack direction was depend on fixing methods of lamination stack and decreased with increase of the inter-lamellar air gap. Removal of the inter-lamellar air gap using glue is effective to improve heat transfer of the high performance motor core which adopted electrical steels with higher alloy and/or thinner gauge.