Design Process of Working Bar of Double-Cage Induction Motor

Double-cage rotors are used to produce induction motors with high efficiency and high starting torque. Most often, experience constants are used in the design of the working bars of double-cage rotors. However, an error occurs, resulting in lower efficiency than actual in the characteristic analysis results. In this study, a new working bar design process is proposed using correct factor and regression, instead of using the existing experience constant when designing the working bar of the double-cage rotor. The performance of a 15-kW-class construction motor model using the existing experience constant was compared with that of the proposed design process through magnetic equivalent circuit (MEC). Finally, the finite-element method (FEM) and start-up performance tests proved the validity of the process.