Adaptive speed identification for vector control of induction motors without rotational transducers

A model-reference adaptive system (MRAS) for the estimation of induction motor speed from measured terminal voltages and currents is described. The estimated speed is used as feedback in a vector control system, thus achieving moderate bandwidth speed control without the use of shaft-mounted transducers. This technique is less complex and more stable than previous MRAS tacholess drives. It has been implemented on a 30 hp laboratory drive, where its effectiveness has been verified.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>