Skin Effect Factor Along the Rotor Bar Extension of Squirrel Cage Induction Motors

摘要

An accurate estimate of the skin effect factor (SEF) in the rotor bars of squirrel cage induction machines (SCIM) is crucial for the calculation of staring torque since the developed torque is directly proportional to the bar resistance with the currents induced in the rotor at line frequency. The rotor bar extension beyond the core of certain large SCIM can represent a significant portion of the whole length of the bar. Inaccuracies in starting torque calculations may be significant depending on this length of bar extension.