Finite-Element Evaluation and Eddy-Current Loss Decrease in Stator End Metallic Parts of a Large Double-Canned Induction Motor

Large double-canned induction motor has high power density and usually works in a closed environment. Compared with a common induction motor, there are many contacted metallic parts in the stator end region of a large double-canned induction motor, in which eddy current will exist not only in end metallic parts themselves but also between contacted metallic parts. Evaluation of eddy-current losses in stator end metallic parts and reasonable end structure design is the premise of ensuring the safe and stable operation of a large double-canned induction motor. A 5-MW-scale double-canned induction motor is taken as an example in this paper, and the 3-D eddy-current field finite-element calculation model of its stator end is established and solved. Then, the eddy current in stator end metallic parts and between different contacted stator end metallic parts is analyzed in detail. On this basis, the eddy-current losses´ decrease method through cutting off the eddy-current path between contacted stator end metallic parts is proposed and validated by experimental results of temperature.