DEVICE TO CONTROL ARMATURE AND FIELD CURRENTS OF TRACTION MOTOR Russian patent published in 1997 - IPC

FIELD: electric transport; electric rolling stocks with automatically controlled separate excitation of DC traction motors. SUBSTANCE: increased reliability, accuracy and quality of control are provided owing to introduction of lag filter, comparator unit and asymmetrical matching amplifier into proposed device and change of place of connection of scaling amplifier. Negative equivalent feedback is used in device although field current feedback is positive. Thanks to it required relationship between armature and field currents is maintained by regulating difference in currents and not only armature current as a function field current or field current as a function of armature current, as in known design versions. EFFECT: improved reliability and accuracy. 1 dwg