| 摘要 |
<p>A variable-speed multi-phase squirrel-cage induction motor which is driven by a variable-frequency power source of the pulse-width modulation type, which exhibits constant torque characteristics when it runs at speeds lower than a predetermined rated speed, and which exhibits constant output characteristics when it runs at speeds higher than the predetermined rated speed. The number of series conductors has been selected on the stator side of the motor, so that the motor runs at speeds faster than said predetermined rated speed when the frequency of said variable-frequency power source is increased to be higher than a commercial frequency. Therefore, the output can be increased without changing the external size of the motor.</p> |
