Analysis of voltage measurement techniques for direct torque control of induction motors

The knowledge of the real stator voltages is basic for a correct estimation of stator flux and torque in direct torque controlled induction motors. In this paper, two different low-cost and effective techniques are presented for stator voltage acquisition: one based on an electronic circuit and the other based on software programming. Both of them have been developed and applied to a direct torque control (DTC) scheme. Experimental tests demonstrate their suitability when controlling an induction motor. A comparative of the two mentioned techniques is presented.