ES144357U - A device for the control of electric motors. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

A device for controlling electric motors, comprising drive motor means; first, second and third controlled rectifying means for coupling electrical power from a first, a second and a third line, respectively, of a three-phase alternating current source to said motor; regulator means responsive to reference signals from a control source and feedback signals from a feedback circuit, to provide drive signals that control the firing phase angles of said controlled rectifier means; pulse generating means for providing a separate train of firing pulses, having a frequency substantially higher than the frequency of said source, to each of said controlled rectifying means, each of the pulse trains starting at the phase angle of day of each of said controlled rectifying means and ending at the end of a driving period of each of said controlled rectifying means, said pulse generating means comprising a first pulse generator responsive to said regulating means and the voltage applied to said first controlled rectifying means for applying a pulse train to said first controlled rectifying means at the tripping phase angle of the voltage directly biasing said first controlled rectifying means; a second pulse generator responsive to said regulating means and to the voltage applied to said second controlled rectifying means for applying a pulse train to said second controlled rectifying means at the trigger phase angle of the voltage directly biasing said second controlled rectifier means; a third pulse generator responsive to said regulating means and to the voltage applied to said third controlled rectifying means for applying a pulse train to said third controlled rectifier means at the voltage trigger phase angle which directly biases said third controlled rectifier means; means responsive to the initial application of firing pulses to said second controlled rectifying means for driving said first pulse generator out of conduction; means responsive to the initial application of firing pulses to said third controlled rectifying means for driving said third pulse generator out of conduction. (Machine-translation by Google Translate, not legally binding)