FEM analysis of concentrated coils nonuniform slot (6+6/8) IPMSM fed with trapezoidal current

This paper investigates an interior permanent magnet synchronous motor with 8 rotor poles and nonuniform (6+6) stator slots and concentrated windings fed with trapezoidal currents, in order to maximize the pole flux, while keeping a minimal level of cogging torque simultaneously. Dimensioning procedure of the proposed solution was done based on experience and it was validated using Finite Element Method (FEM). FEM-analysis of the case study design solution offers direct results for: field distribution at no-load and at load, back-EMF at no-load, cogging torque (zero current), load torque pulsations, reluctance torque pulsations, torque-rotor angular position characteristics for different trapezoidal-current shapes, torque-rotor angular position characteristics for different current amplitudes, and saturated synchronous inductances. With the prototype already in place experimental work is due soon.