Abstract
In the induction motor drive using sensorless control or vector control, the control calculation is performed based on motor constants. Motor constants are obtained by no load test and lock test. However no load test and lock test are inapplicable to the induction motors joined to machines.
This paper suggests the novel method of motor constants measurement without rotating for induction motors. The feature of this novel method is measuring only imaginary part of equivalent impedance of T type equivalent circuit of the induction motor on stop state by supplying the low frequency alternating voltage when measuring mutual inductance and rotor resistance. The reason is because the measured value of the real part of equivalent impedance is not exact because of the error of stator resistance and the voltage error which the dead time causes.
It was confirmed by the experiment that this novel method enables to set control parameters correctly and to drive stably induction motors joined to machines with speed sensorless vector control.
