Influence of Tooth-tips on Dual 3-phase Modular Permanent Magnet Machines with Redundant Teeth

Three kinds of tooth-tips are analyzed to show their influence on the electromagnetic performances of dual 3-phase modular permanent magnet machines with redundant teeth. For symmetrical tooth-tips, each tooth is symmetrical to its own center line. However, the tooth-tips can also be accommodated in either the left or right side of each tooth. Since both the open-circuit and armature field distributions are affected due to the existence of these tooth-tips, the corresponding machines will show different performances, such as back-EMF, cogging torque, on-load torque, etc. It can be found that each kind of tooth-tip has its own advantage. Therefore, the adoption of tooth-tips needs to be determined according to the specific requirement.