An automated secondary resistance identification scheme in vector controlled induction motor drives

The authors describe an induction motor secondary resistance identification method in a voltage source pulse-width modulation (PWM) inverter. In order to estimate the resistance under any conditions, a test signal is superimposed on a voltage reference of the inverter. Electromagnetic energy, which is not related to primary resistance, is derived, so the method is independent of variation in the primary resistance. The identification method is tested with a 2.2 kW induction motor, and the experimental results confirm the method´s usefulness.<>