On-line parameter measurement of induction machines

The problem of degradation in performance of an induction machine controller resulting from parameter variation is tackled using an on-line measurement technique which may be used as an alternative or supplement to parameter adaption. Experimental data shows that a test similar to the locked-rotor test may be successfully performed by injecting a low magnitude, high frequency voltage set into the motor supply. Experimental results show consistent measures of induction machine stator and rotor resistance parameters are obtained. Guidelines for maintaining accuracy under various operating conditions are discussed. A custom PWM generator is developed which improves the experimental process and a detection system using a microprocessor is proposed.