Effects of adaptive PI controller gains on speed estimation convergence and noises at sensorless induction motor drives

This paper presents the effects of adaptive controller gains of a model reference adaptive system based sensorless induction motor drive. In this scheme, an adaptive pseudoreduced-order flux observer is used instead of the adaptive full-order flux observer. The simulation and experimental results show that with the large PI gains for the adaptive scheme, the convergence for the speed estimation is fast, however, higher order harmonics, noises, and overshoots are included in the estimated speed. Usually A/D converters and hysteresis current controller cause noises. The desired gains are a trade-off between a high speed of response, and high robustness to noise.