A circuit approach to finite element analysis of a double squirrel cage induction motor

A method for analyzing the losses and the torque of an induction motor with a double cage rotor is presented. The tentative values for the currents for the analysis are found using an analytical procedure. The parameters of an equivalent circuit are then calculated by means of a finite-element method. The actual current distribution in the rotor bars, including the eddy current distribution, results from the finite-element solution. New current estimates are found from the obtained circuit and are used to establish a corrected field distribution. Using the losses due to eddy currents, the equivalent resistance of the rotor may be calculated, and using the rotor losses, the torques are calculated. Assuming linearity, the complex power yields the inductances. The resulting equivalent circuit can then yield a better estimate for the current. This constitutes an iterative procedure which can be continued to any desired convergence accuracy for the currents