Smart DTC algorithm with automatic torque adjustment

Marko Rosić – Branko Koprivica – Miroslav Bjekić

   The paper presents a direct torque control method with possibilities of automatic algorithm modification in terms of torque ripple reduction. The algorithm is based on the conventional switching table with an arbitrary number of discretized voltage levels allowing higher space-voltage resolution and consequently lower torque ripple. The number of available voltage levels can be easily changed and subsequently torque ripple reduced without the need to modify the conventional switching table. Appropriate algorithm modifications leading to torque ripple reduction are automatized, making this kind of control method simple, effective, and suitable for upcoming smart drives in the rapidly growing industry 4.0. Selective back electromotive force compensation can also be part of automatization with the aim to improve the drive dynamics. Experimental validation presented in the paper confirms improvements in torque ripple reduction retaining the simple and time-effective control structure of the induction machine DTC drive.

Keywords: variable speed drives, direct torque control, AC machines, switching table, automatic algorithm modification, torque ripple reduction, self-tuning

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