Comparison of Rectangular and Trapezoidal Slot Structure Switched-Flux Permanent Magnet Machine utilizing Analytical Technique

Armature Coil Slot Structure (ACSS), Slot Opening Width (SOW) and Stator Tooth Width (STW) can affect flux linkage, cogging torque, Back Electromotive Force (B-EMF), and electromagnetic torque of Switched-Flux Permanent Magnet Machine (SFPMM). SFPMM can be designed having rectangular or trapezoidal ACSS. Limitations of SFPMM such as complex stator structure, complex flux density distribution, and magnetic saturation caused by passive rotor demands to be analyzed by time consuming and computationally complex numerical modelling techniques i.e. Finite Element (FE) method, requiring expensive hardware/software. An analytical method known as Magnetic Equivalent Circuit (MEC). In this paper, two twelve-stator-slot and ten-rotor-tooth (12/10) are designed and analyzed having rectangular and trapezoidal ACSS. Analytical method comprising of MEC with GRN methodology is developed for analysis and verified utilizing globally accepted FE Analysis. Results of FEA and analytical methodology revealed that peak-to-peak open circuit flux linkage for Trapezoidal ACSS (TACSS) is 219.29 milli-Webber and 210 milli-Webber respectively, representing maximum peak error of 1.48%. While, FEA and analytical approach results for Rectangular ACSS (RACSS) is 175.59 milli-Webber and 195.4 milli-Webber respectively, representing maximum peak error of 0.99%.