Chapter 6

Direct Control of a Permanent Magnet Synchronous Machine 1

6.1. Introduction

Direct torque control (DTC) consists of a direct control approach, point of view in order to directly determine the converter optimal commutations from a control objective.

DTC appeared in the 1980s [TAK 85, TAK 87]. Since then, a large variety of algorithms have been proposed, relying on the heuristic refinements of the commutation choice [CAN 00], [HAS 99].

Direct control differs from conventional control and helps to obtain much faster response times. Indeed, within a scalar or vector control, the system to be controlled is defined by a continuous or discrete model; the converter being considered as a simple gain. The control algorithm then determines, at each calculation step, the voltages to be applied to the motor, which, via a PWM technique, dictates the choice of the converter commutations.

Here the focus is on direct control of permanent magnet synchronous machines (PMSM) by different approaches. After a historical review of the DTCs, some improvements to its performance time are detailed through calculation of the inverter configurations on a constant calculation horizon.

Currently, the direct predictive approaches considering the controlled process as a dynamic hybrid system (DHS), are rich in potential in power electronics applications and give promising results [MOR 08] [LIN 07].

This approach is illustrated for the PMSM.

6.2. Model of the permanent magnet synchronous machine in ...

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