Effect of Unequal Tooth Widths on the Performance of an E-core Stator Machine

An electrical machine having both equal and unequal stator tooth widths is developed and compared in this study. The following performance criteria are investigated: torque, flux, electromotive force (EMF), magnetic force, torque ripple, total harmonic distortion (THD) and inductance. Finite element analysis (FEA) technique is implemented using MAXWELL-ANSYS software. It is revealed that the machine model that is equipped with unequal stator tooth width has more competitive performances such as reduced: cogging torque and total loss values; enhanced: torque, magnetic flux, EMF and efficiency values. Nevertheless, with high amount of magnetic force and voltage THD which are unattractive features in ideal electric machine operation. More so, the equal toothed-width model has longer speed range, regardless of its lower torque profile. Over 52% cogging torque and about 40% torque ripple reductions are recorded in favour of the machine type that has unequal stator tooth widths, at rated simulation settings. The developed machine is a good candidate for high torque low speed direct drive applications.