Performance Evaluation of a Combined Star-Pentagon Connected Five-Phase Induction Machine with a Stator Coil Fault

This paper evaluates the performance of a five-phase induction machine (FPIM) with a combined star-pentagon stator winding, operating with coil faults. The NEMA frame of a conventional three-phase, four-pole, 5.5 kW, 50-Hz, 4-pole, 36-stator slots induction motor (IM) is employed to achieve the desired five-phase combined star-pentagon winding configuration. The FPIM was modeled utilizing a two-dimensional (2D) Finite Element Method (FEM). The ac magnetic transient and magnetostatic solvers of the FEM were used to evaluate some of the negative outcomes of a coil fault on crucial electromagnetic parameters of the FPIM. A 36-stator slot five-FPIM prototype with a combined star-pentagon stator winding arrangement was tested to that effect. The FEA results evidenced that the line current of the affected phase and torque ripples of the 36-stator slot of the FPIM with combined star/pentagon winding increased by 1.88% and 105.7%, respectively, when operating with a coil fault. On the other hand, the line current of the affected phase and torque ripple increased by 22.35% and 544.87%, respectively, in FPIMs with conventional 40 stator slots. The measured results obtained from the laboratory proved that the line currents of the affected phase increased by almost 17% when operating with a coil fault.