Tetsuo Fujigaki

Starting torque analysis of cage induction motor using permeance model considering magnetic saturation by leakage flux

This paper describes a method to analyze harmonic components of the air-gap flux density distribution and the torque of 3-phase cage induction motors, considering the influence of circumferential slot arrangement, stator winding pattern, and distribution of air-gap permeance due to leakage flux. The proposed method is based on an analytical model of the permeance and magnetomotive force distributions. The proposed method considers magnetic saturation caused by the main and leakage magnetic flux. As a result, the harmonic components of the torque in the starting condition can be determined quantitatively. From the comparison between the calculated and experimental results, the proposed method is shown to be appropriate and useful for quantitatively estimating harmonic torque for cage induction motors.

Magnetic flux density analysis of wound rotor induction motor by permeance model

A fast calculation method for parametric survey is needed when designing motors. We propose a new method for analyzing the harmonic components of air-gap flux density distribution in three-phase wound rotor induction motors. The proposed method is based on analytical equations for permeance and magnetomotive force distribution, considering the influence of the circumference slot arrangement and winding pattern of the motor. Thus, the harmonic components of the air-gap flux density distribution can be analyzed in a short time. The analysis results of the proposed method are in agreement with those of finite element magnetic analysis in on-load condition. Consequently, this method is shown to be suitable for quantitatively estimating the flux density of wound rotor induction motors and useful for parametric survey when designing wound rotor induction motors.