Energy-saving in constant speed running motors by means of adaptive sinusoidal voltage

A transformer-based, purely sinusoidal, energy-saving controller for induction motors is presented. The controller applies a three-phase transformer in a reconfigurable scheme to create three different voltages. A simple control scheme is then applied to set the `right voltage´ to supply the motor. Significant reductions in the real and reactive power consumption were noticed, especially in motors operated under low load.