Experimental Investigation of Contact Resistance for Water Cooled Jacket for Electric Motors and Generators

The key to the successful implementation of water jacket frame cooling in high-power electric machines, such as permanent magnet, doubly fed induction, and synchronous generators, is the contact between the laminated stator core and the frame. For improved thermal design, it is important to quantify the contact thermal resistance between lamination and frame. This paper quantitatively presents the values of conventional stator lamination and frame interface resistance through experimental results. So far, no experimental investigation has been carried out to determine this resistance. The effects of several parameters, such as surface finish, shrink fit pressures, use of thermal grease, and phase change thermal interface material on thermal contact resistance, have been experimentally investigated. The obtained values of thermal contact resistance between laminations and frame can be applied for future thermal designs of electric machines to predict accurate thermal performance.