Simple dynamic loss-minimizing flux level control of field-orientation induction motor drives

Abstract

The current paper discusses the adaptive choice of a filter time constant for filtering the steady-state flux reference in the energyefficient control problem of field-orientation induction machines in transient behavior when load and speed conditions are changing taking into account the effect of the main induction saturation. It is shown that by appropriately managing the flux linkage rate of change the energy losses per full operation cycle under torque changes can be significantly reduced compared to the conventional cases. The analysis for the appropriate choice of the filter time constant as a fraction of the rotor time constant is based on a numerical study and simulation results for three different induction machines with different rated powers.