Impact Analysis of Number of Broken Rotor Bars and Rotor Bar Shape Types through Illation Method for Asynchronous Motors

A method that analyses the impact that entails the specific interaction between the number of rotor broken bars and different rotor bar shapes of a three-phase squirrel cage asynchronous motor (SCASynM) is presented in this paper. The method utilizes the single-and multi-factor experimental design, combined with analysis of variance (ANOVA) and Finite Element Analysis (FEA) to quantitatively and qualitatively determine the significance of number of broken rotor bars and different types of rotor bar shape on the response variables, which are the average torque, torque ripple, efficiency and power factor. Although the ANOVA results of the single-factor experimental design showed that the effects of number of broken rotor bars on efficiency response are insignificant, but the same results evidenced that both the average torque, torque ripple and power factor as response variables are affected by the number of broken rotor bars. On other hand, the ANOVA results of the multifactor experimental design proved that increasing the number of broken rotor bars for different rotor bar shapes has a statistically significant impact on the average torque and the torque ripple. As far as the efficiency and power factor are concerned, the rotor bar shape affects both response variables, while increasing the number of broken rotor bars from zero to three does not show any significant impact on these response variables.