High speed sensorless control for induction machines in vacuum pump application

A sensorless rotor field oriented control of an induction motor drive for high speed vacuum pumps is presented in this paper. Motion sensorless control is mandatory for this application, due to space constraints, hostile environment, cost reasons and reliability. The adoption of field oriented control instead of the conventional V/Hz control is justified by the application peculiarities. The complete system is described including the motor, the converter and the control features. Experimental results are provided for a drive in production.