Analysis of a Deep Bar Induction Motor and Compressor Load During Start-Up

An expanded rotor equivalent circuit model of a deep bar induction motor has been implemented using a steepest descent algorithm. Further accurate fitting of test data is achieved by incorporating saturation of the rotor teeth. The model is used to study electro-mechanical interactions that cause shaft torque amplification during starting of the induction motor. Results of the time domain simulation are compared to a frequency domain (eigenvalue) analysis and simplified mathematical models are derived to describe the mechanism of instability.