A calculated determination and experimental refinement of the optimal value of the single-phase induction motor transformation ratio

Keywords: Induction motor, windings, phase-shifting capacitor, efficiency, positive and reverse sequence currents Induction motors consume almost 70% of the world’s electricity as they are the driving force behind the vast majority of rotary mechanisms [1]. For industrial and domestic purposes alone, about a million new electric motors are commissioned annually. Single-phase induction motors (SPIMs) are superior to all other types of electrical machines that operate on a single-phase AC voltage network because of their simple and robust design and low cost. Therefore, a small improvement in the SPIM energy performance can have a strong impact on energy consumption worldwide and ultimately reduce emissions of harmful substances into environment. This article presents a technique for optimizing SPIM windings in order to maximize efficiency with a given and fixed phase-shifting capacitor. The positive effect of the application of the proposed method is confirmed by the results of SPIM industrial tests with various powers and rotor speeds.