Input power minimization of an induction motor operating from an electronic drive under ripple correlation control

This paper elaborates on the application of ripple correlation control (RCC) to induction motor input power minimization. Simulations, hardware experiments, and frequency analyses verify that the direct component of the rotor flux in the synchronous frame (lambda
^e

_dr
) can be adjusted to minimize the input power to the motor while maintaining the required output power. Motor characteristics are shown to give a convex input power function with respect to lambda
^e

_dr
which could be feasible for optimization using RCC. Sensitivity analyses based on RCC of a boost converter and for an induction motor are presented. A Simulinkreg simulation shows the convergence of the ripple correlation controller to the optimum operating point that was determined by hardware experiments. Other results include the use of flux estimators from stator-side voltage and current measurements. Efficiency improvement has been verified across the load torque range, including light load conditions.