Analysis of the rotor bar geometry´s effect on the induction motor performance with finite element method

In this work, the effect of using different rotor bar geometries on the motor performance is analyzed for an industrial three phase squirrel cage induction motor which has 4 kW, 4 poles, 36 stator bars, 28 rotor bars. Motor geometries are created by using Finite element method (Flux2D^©). Both frequency domain and transient magnetic analyses were performed to obtain the performance curves. Numerical performance analysis results are also compared to the experimental data. In order to improve the induction motor performance, deep rotor bars and double cage rotor bars were designed by using the finite element program. Although deep rotor bar design shows that the starting torque of the motor is lower than expected at the frequency domain analysis, the time domain analysis results for the same deep rotor bar design results three times higher starting torque value compared to that of initial motor design at first cycle. Double squirrel cage bar design among the all designs shows the highest starting torque as expected.