Analysis of non-uniform magnetic flux distribution in conical rotor double-speed induction motors

The variable geometric dimensions of the magnetic circuit in the conical rotor induction motors in axial direction makes the magnetic flux non-uniform distribution in the length of the magnetic core. An analytical multisectional method for electromagnetic calculation has been developed accounting the special features of the motor design. It allows obtaining correct values of the magnetic flux density distribution and preventing oversaturation in some parts of the motor core. Numerical results for the non-uniform distribution of the magnetic flux density in the air-gap, teeth zone and yokes in longitudinal direction have been presented for two analyzed motors.