| 摘要 |
A standard, unmodified AC induction motor has its stator winding energized from a sine wave source through a signal-responsive wave modifier operative to control the portion of each cycle of the sine wave which is coupled from said source to the stator winding. A motor current demodulator, responsive to efficiency-related parameters of the inrush current to the stator winding each time the current in the stator winding increases from zero, produces a control signal for the wave modifier, which signal varies with a decrease in motor operating efficiency below the maximum inherent efficiency of the motor to increase the field density of the stator winding in response to increases in motor load and to decrease said stator field density in response to decreases in said load and/or to maintain the most energy-efficient stator field density at rated motor loads when the voltage magnitude of the sine wave source increases or decreases from its nominally rated magnitude. |
