THYRISTOR-CONTROLLED DC TRACTION ELECTRIC DRIVE Russian patent published in 2003 - IPC

FIELD: transport engineering. SUBSTANCE: proposed traction electric drive contains supply source, switch, two dc traction motors with armature windings and field windings, field current and armature current sensors and field current breaker. The latter contains main thyristor, blanking thyristor, switching capacitor, field weakening contactor and resistors. Two matching units, scaling amplifier, comparator, control unit, antiskid and antislip unit and shunting contactor with corresponding couplings are introduced additionally into drive. Proposed drive features higher reliability in operation, particularly, when operating under transient conditions owing to the fact that value of voltage across switching capacitor at any transient duties is sufficient for disabling main thyristor. As compared with known devices, proposed electric drive is of smaller dimensions as it uses switching capacitor of lower rating. EFFECT: improved reliability, reduced overall dimensions. 1 dwg