Comparison of steady-state induction motor-drive efficiency control schemes

Steady-state motor efficiency control has been shown to provide significant motor loss savings and efficiency improvement. Including adjustable speed drive inverter losses into the steady-state motor control optimization is also of interest. What is shown here is the effect that these two efficiency improvement schemes have on the distribution of losses between the motor and the inverter when an efficiency control scheme is applied to the motor-drive system. It will be shown in this paper that the choice of motor loss optimization versus system loss optimization should not only be determined by the loss improvement for the motor, but also by careful consideration of the re-distribution of losses caused by loss optimization control.