Slot Numbering and Distributed Winding Effects Analysis on the Torque/Current Spectrum of Three-phase Wound-rotor Induction Machine Using Discrete Modeling Method

Abstract

Smooth torque production by induction machines is an improbable phenomena that is taken into account only in classic and ideal studying methods. In this research, slot numbering and also non-sinusoidal winding function effects are studied for a three-phase wound-rotor induction machine, which is addressed for the first time, and a new formula is introduced for calculating the spectral components of machine torque and current. To reach this aim, mathematical modeling of the air-gap function is proposed, and a discrete time modeling of the machine is introduced to study the effects of space harmonics on the torque/current spectral. To study the mentioned phenomena, in the first part, the winding functions are considered as ideally sinusoidal and the behavior of simulated machines is investigated based on the winding function approach and numerical method analysis. Two certain formulas are introduced for the spectral components of torque ripple and stator currents according to the slot numbers, rotor speed, and number of machine poles. In the second part, slot opening effects are neglected and non-sinusoidal windings are considered for obtaining the same results. Finally, considering both effects, model validation is confirmed by a finite-element-based method, and the introduced method is proven.

Keywords:

• air-gap function
• distributed winding
• slot opening
• sinusoidal winding function

Additional information

Notes on contributors

Peyman Naderi

Peyman Naderi was born in Ahvaz, Iran, in 1975. He received his B.S. in electronic engineering in 1998 and his M.S. in power engineering from Chamran University, Iran, in 2001. He has a Ph.D. in power engineering science from K.N. Toosi University, Tehran, Iran. He is currently an assistant professor in Shahid Rajaee Teacher Training University of Tehran, Iran. His interests are hybrid and electric vehicles, vehicles dynamic, power system transients, and power system dynamics.

Ali Taheri

Ali Taheri was born in Shiraz, Iran, in 1984. He received his B.S. in 2006 from Shiraz University, Shiraz, Iran, and his M.S. in 2014 from Shahid Rajaee Teacher Training University, Tehran, Iran, both in power engineering. He is currently a teacher in electrical science schools. His interests are electrical machines and dynamical system modeling.