Containment can losses in permanent-magnet pump drives

The integrated “pump-motor-containment” concept is a development in the chemical process industry. Both the stator and rotor members are isolated using stainless-steel containment cans. During normal operation, however, losses are generated in the stator can due to the stator excitation and the permanent magnets mounted on the rotor. A layer model has been developed to analyze the pseudothree-dimensional current flow in the stator can and hence predict the can losses. This represents an application of this particular analytical approach. The layer model is validated using a 10 kW experimental pump motor and a subsequent design study has demonstrated that the stator can losses are a significant factor in ensuring the integrity of the containment system. It has also been shown that the thickness and overhang length of the stator containment should be minimized to reduce the losses subject to mechanical constraints.