Comparison of the performance of bridge and bridgeless shaded pole induction motors using FEM

Two 15W shaded pole motors with bridged and without bridge type stators were modeled using 2D and 3D analysis were performed using finite element analyzes. The magnetic behavior of the motor was determined by obtaining the magnetic flux density over the cross section of the motor and the air gap flux waveforms. Recently, a new modified structure of these motors has started to be seen in the literature, and this structure is called the bridged structure. The flux value transferred to the rotor in bridgeless motors is greater than with the bridged stator type. The harmonic components were obtained by making the Finite Fourier analyses of the waveforms of flux densities. It was determined that the bridged structure had the disadvantage of having stronger harmonics than the bridgeless structure. The magnetic performances of 4 different rotor structures were examined in the rotor part of the bridgeless-type motor. The number of rotor slots were modified between 16 and 32 by selecting Type 1 on these different rotors. The optimum number of rotor slots was determined to be 26. It was stated that determining the optimum number of slots in the design of these motors would provide significant improvement in the performance.