DIRECT TORQUE CONTROLLER AND CONTROL METHOD FOR THREE-PHASE MACHINE

摘要

PROBLEM TO BE SOLVED: To brake vibration caused by a filter effectively, without modifying the conventional method and apparatus significantly by correcting the values of reference flux and reference torque, based on the current flowing through a filter and/or the output voltage thereof. SOLUTION: Output voltage of a filter is measured for each phase and variables, corresponding to the stator flux, are determined by means of a multiplier 5 and a subtractor 7. The voltage is divided into a parallel component and a right-angle component, and then the voltage is multiplied by the stator flux by means of a vector product forming-element 9 and a scalar product- forming element 10. Each component passes through a multiplier 5 and a limiter 6, before being subtracted from a reference flux value. Consequently, conventional DTC method and the essential part of a corresponding apparatus can be used, without requiring significant changes, and vibration caused by the filter can be braked effectively.