CFD and LPTN Hybrid Technique to Determine Convection Coefficient in End-winding of TEFC Induction Motor with Copper Rotor

Convection coefficient in the end-winding is a critical thermal parameter in Lumped Parameter Thermal Network (LPTN) model solution for an accurate motor winding temperature prediction. However, it is a challenging task to determine this convection coefficient due to complex heat and air circulation characteristics in the end-winding region. Until now, all researches focus on Totally Enclosed Fan-cooled (TEFC) Aluminum Rotor Induction Motor (ARIM) with a rotor having fins on its end-rings. But Copper Rotor Induction Motor (CRIM) has a rotor that does not have any fins on its end-rings. Hence, this research will determine convection coefficient in the end-region of Copper Rotor Induction Motor (CRIM) that has smooth rotor end. A Computational Fluid Dynamic (CFD) technique along-with a Lumped Parameter Thermal Network (LPTN) model is proposed to determine this convection coefficient. Thermal experiments on a 20-hp Copper Rotor Induction Motor (CRIM) are conducted to validate this proposed approach.