Measurement of equivalent circuit parameters of inverter fed induction motors

For an accurate prediction of the steady state performance of inverter fed induction motors it is required to determine the parameters of the fundamental and time harmonic equivalent circuits of the motors. A new method to measure these parameters using digital techniques is presented. This method is applied to an experimental induction motor, and its parameters are measured. From this, some characteristics of the parameters, such as voltage characteristics of the exciting inductance and iron loss resistance and frequency characteristics of the secondary resistance and leakage inductance, are clarified. Finally the fundamental and harmonic currents of the experimental induction motor fed by a voltage source inverter are predicted using the equivalent circuit parameters obtained, and they are compared with the measured results.