A multi induction-motor drive strategy operating in the sensorless mode

This paper describes the development of a sensorless induction motor drive scheme that can be used for high-performance process control applications where multi-motor speed synchronisation is required. The scheme employs a model reference adaptive system (MRAS) to provide a direct field orientated drive with speed estimation. Tuning of the MRAS is achieved using a measurement of speed derived from the rotor slot harmonic content of the stator current. The performance of the system matches that achieved using an encoder and excellent speed synchronisation of two drives is demonstrated experimentally.