A synchronised multi-motor control system using sensorless induction motor drives

This paper outlines a high-performance induction motor sensorless control strategy engineered for high speed holding accuracy. The strategy utilises a model-based method, tuned by a speed estimate derived from rotor slot harmonic effects seen in stator quantities. Two 4 kW machines, both running the developed scheme, are speed synchronised using a bi-axial cross-coupled control method. Results are shown to be comparable to those obtained from the same synchronisation scheme, and on the same rig, using encoded indirect rotor flux oriented (IRFO) control.