Kramer system utilizing a commutatorless motor
AssigneeHitachi, Ltd.
InventorsMitsuyuki Honbu, Sanshiro Obara, Takamasa Hori
Life of this patent
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Abstract
A speed control system for an induction motor controlled by a converting arrangement coupled with a commutatorless motor which operates without commutation failure notwithstanding wide variations in the speed of the commutatorless motor. The speed control system includes an arrangement for maintaining the value of a direct current signal of the converting arrangement less than the maximum current value for ensuring proper operation of the converting arrangement.
Claims9
A speed control system for an induction motor, comprising an induction motor having a winding providing an output, a load driven by the induction motor, a synchronous motor mechanically connected to the induction motor, converting means responsive to the output of the winding of the induction motor for providing a direct current signal and therefrom an alternating current signal for application to the synchronous motor, the converting means including thyristor means, a current signal generating means supplying a current signal to the gates of the thyristor means of the converting means in accordance with a desired speed value and the actual speed value of the synchronous motor, and function generator means for varying the current signal generated by the current signal generating means to maintain the value of the direct current signal of the converting means less than a maximum commutation current value and greater than a minimum load current value in accordance with the actual speed value of the synchronous motor.
Dependencies are inferred from the claim text.