A Detailed Study for the Determination of Phase Inductances of a Shaded-Pole Induction Motor with Variable Air Gap

Abstract

Shaded-pole induction motors (SPIMs) are extensively used in industrial applications, home appliances and ventilation systems due to their simple structure, low cost and low maintenance requirement. Formation of elliptic rotating field in SPIM makes its analysis rather complex. As the result of this complexity, there are relatively limited publications on the theory, design and analysis for this kind of motor. In many cases, its design is based on trial and error method. As it is appreciated, the accuracy of predicted performance of electric machines is closely related to the accuracy of the winding inductances used in calculations. For this reason, in this study, stator and shading-rings end-winding leakage inductance, stator winding self-inductance, total leakage inductance of the stator winding and the mutual inductance between stator and rotor winding of a 4-pole SPIM are obtained by means of the derived analytical equations and real-time experiments. Also, the effect of magnetic saturation on the stator self and leakage inductances, and the variation of stator-rotor mutual inductance with respect to the rotor position have been investigated. At the end of the study, the accuracy of computed stator winding self-inductance is validated by an experimental exercise.

Keywords

• Shaded-Pole Induction Motor
• Phase Inductances Magnetic Saturation Mutual Inductances
• Phase Inductances
• Magnetic Saturation
• Mutual Inductances