摘要 |
<p>This invention relates to a control system for an induction motor which has power factor control means for altering the power factor of the input current of a converter composed of self-arc extinguishing elements, such as transistors, to vary the d.c. output voltage of the converter to perform a pulse-amplitude modulation control in a variable voltage, variable frequency controller for controlling the rotating speed of the induction motor by the converter of a sinusoidal wave input to reduce noise generated by the operation of the motor.</p> |