Sensorless Control of IM in Mining Applications

A power inverter applying a speed sensorless induction motor control is presented in the paper. It was designed with the goal to be used in applications positioned in the Ex-environment of the underground mines. Direct field oriented control, using rotor flux and speed observer is used. The speed sensorless observer scheme is based on the back-emf observer. Applied hardware and software are presented. Operation is described with the use of experimental results, which were obtained from the actual application operating in the coal mine. The project is a good example of cooperation between the academia and industry.