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Power factor and efficiency characteristics of an induction motor with free rotating magnets
Author(s) -
Shibata Yoshiyuki,
Tsuchida Nuio,
Imai Koji
Publication year - 1999
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/(sici)1520-6416(19981130)125:3<59::aid-eej7>3.0.co;2-y
Subject(s) - power factor , induction motor , voltage , power (physics) , rotor (electric) , wound rotor motor , universal motor , electrical engineering , voltage drop , torque , engineering , control theory (sociology) , automotive engineering , physics , computer science , control (management) , quantum mechanics , artificial intelligence , thermodynamics
We have developed a unique induction motor that has free rotating magnets inside its rotor. In experimental results for a prototype motor, we have obtained superior performance over existing motors in terms of the power factor, efficiency, and output torque. The experimental details are as follows. The power factor of the test motor is significantly improved in comparison with that of a conventional induction motor. The power factor can be held to be unity, leading or lagging by changing the line frequency and/or source voltage. This is a quite unique feature, because the power factor of the usual induction motors always lags. The improvement of the power factor is effective not only in decreasing current loss, but also in decreasing voltage drop in the line and increasing installation capacity. The efficiency of the motor is remarkably higher than that of similar‐sized conventional induction motors over a wide output power range. Actually, in ordinary induction motors, the efficiency is reduced as the power and/or the source voltage are decreased. However, the proposed motor is driven at high efficiency by lower source voltages in lower power ranges. The efficiency is improved by reducing the secondary current and the magnetizing current. © 1998 Scripta Technica, Electr Eng Jpn, 125(3): 59–66, 1998