Experimental Study of Oil Cooled Induction Motor for Hybrid and Electric Vehicles

In this paper, we present an experimental study of a new design of the traditional Totally Enclosed Fan-Cooled (TEFC) induction motor. This design proposes to remove the turbine fitted on the external part of the shaft and add a hollow shaft with holes on its surface. These holes allow the oil coolant to be projected inside the motor on the stator end-windings and rotor end-rings and thus, cooling these parts. The major idea is to present a proof of concept about the effectiveness of oil cooling applied on electric motors by testing the cooling performance with oil versus the traditional cooling and study the gain in continuous power between these two designs. To achieve this, we present the experimental apparatus for the oil-cooled induction motor and we perform different tests. We finally show results on continuous power with different oil flowrates and for two types of oil, as well as friction losses due to oil injection.