3 METHOD AND APPARATUS FOR DIRECT TORQUE CONTROL OF A THREE-PHASE MACHINE

摘要

The method and apparatus for direct torque control is applied to a three-phase machine fed through a harmonic filter, which method can be managed without major modification of the already known DTC methods and DTC apparatus. In addition, the vibration generated by the filter is effectively attenuated. This is accomplished by measuring the current flowing through the filter and / or the filter output voltage, and the reference flux value and the reference torque value are corrected based on the measured voltage and / or the measured current. The correction includes transforming the filter output voltage into a first component perpendicular to the stator magnetic flux and a second component parallel to the stator magnetic flux and reducing the reference torque and magnetic flux value in proportion to the oscillation portion of the filter output voltage.