Modeling and analysis of a shaded-pole and C-core induction motor

Shaded-pole induction motors belong to the group of most used small electric motors in low-power applications ranging from a fraction of a watt up to few 100 W. They are most often found in fan drivers, small pumps, beverage dispensers, washing machines and many household appliances. They are frequently used due to their advanced manufacturing technology, cost effectiveness, robustness, reliability and low noise and vibration levels, despite their poor efficiency, which is usually below 40%. The shaded-pole motors are often designed as two -pole machines. Depending on the construction of the stator package of the two-pole version, they can be divided into symmetrically and asymmetrically designed motors. The objective of the paper is to build a 2D finite-element-based numerical model of a C-shape shaded-pole induction machine (i.e., asymmetrical type) using the transient magnetic analysis. The impact of the number of the auxiliary winding turns and the rotor skewing angle on the resulting torque-speed curve and the torque pulsations is investigated. Finally, the possibility is considered to reduce the amount of the used material to simplify the manufacturing, which may be important for the recycling and/or reuse process.