Characteristics of high-speed constant-voltage operation of squirrel-cage induction motors -the influence of gap length in 4- and 8-pole induction-

Recently, three-phase squirrel-cage induction motor (IM) has been frequently used as variable-speed motor driven by an inverter system. Generally, its losses increase and efficiency decrease when it is operated at high speed. Therefore, in this paper, we discuss the characteristics of eight motors with different gap lengths in relation to the experimental results.