A FEM-Based Comparative Study of the Effect of Rotor Bar Designs on the Performance of Squirrel Cage Induction Motors

Abstract

Induction motors (IM) are the most frequently used type of motor in the industry. The number of rotor slots, bar geometry, and conductivity of bar material have a strong impact on the torque profile and efficiency characteristics of induction motors. This study focused on investigating the effect of different rotor bar designs on motor performance by the finite element method (FEM). The IMs have been designed using the same stator core, winding, and core lengths. The total rotor bar cross-section areas are also fixed throughout all designs. In addition to the change in the number of rotor bars and geometry, the effect of copper and aluminum bar materials on motor performance was also investigated, both for single and double-layered squirrel-cage structures. The results of the study indicate that the starting torque of the motor in a 36/30-slot aluminum single-cage structure was obtained as 96.26 Nm, while the starting torque of a 36/46-slot aluminum double-cage structure was found to be 115.34 Nm. It is also found that the starting torque of the initial design can be increased by up to 19.82% by changing only the rotor bar numbers and material with the same stator and rotor size. The efficiency of the motors was determined as 86.6% for both designs. In addition to efficiency, the output torque ripple has been decreased to 2.63, which equals a 67.32% decrease in the ripple of the initial design. The improved design has an approximately 8 °C lower T2 due to better cooling performance as a result of a higher number of rotor slots.

Feasibility of Six Metaheuristic Solutions for Estimating Induction Motor Reactance

“…A novel approach to determining the double-cage method parameters of squirrel-cage induction motors was presented in a study. The machine impedance was measured at several places to approximate the motor characteristics [9]. Through the use of machine labels and manufacturer catalog information, a new, simple, and non-repetitive methodology for deriving equivalent circuit characteristics of an asynchronous machine was described in another study.…”

Enhancing efficiency of magnetic energy by implementing square-shaped materials adjacent to induction machine windings

“…Addressing these issues necessitates adjustments in torque and power factor. A holistic approach to improve magnetic energy involves core material selection, winding design, insulation, and advanced control techniques, significantly enhancing effectiveness and performance in various industrial applications [15][16][17] [18]. Despite limitations in starting torque for induction machines remain popular due to their reliability, simplicity, and affordability.…”