Extended Space Vector Method for Calculation of Induction Motor Parameters

In this article, a novel method for the determination of spatial vectors of multi-phase windings is proposed. The proposed method is applied to squirrel-cage induction motors and it allows for the calculation of the rotor currents space vectors with any slot number (even and odd), that cannot be determined by classical expressions. On the basis of current space vectors and current flux linkages, the proposed method determines the flux linkage phasors. The current and flux linkage phasors of the stator and rotor make it possible to determine the leakage and magnetizing inductances of the rotor and stator for any operating point on the basis of finite-element analysis of the motor model without any further calculations. The new method, besides the motor parameters, allows determination of the motor torque components developed by higher harmonic components of current, which significantly affects the resultant motor torque. The validity of the proposed method is verified by comparison of motor parameters determined from finite-element analysis with the parameters determined by running no-load and locked rotor tests on an actual motor.