| 摘要 |
DC traction drives. SUBSTANCE: electric drive has two current collectors, output-filter reactor and capacitor, smoothing reactor, electric motor with armature and field windings, converter, starting, braking, and auxiliary contactors, starting, braking, auxiliary, and additional diodes, braking, limiting, shunting, additional, and ballast resistors, current and voltage sensors, control unit, operating-voltage setting device, and switch. Converter may have main and auxiliary pulse choppers and back diode. Control unit may incorporate RS flip-flop, reference-voltage source, NAND gate, and comparator. Electric drive incorporates provision for its short-circuit and overload protection under braking conditions ands for limiting surge voltages across motor armature winding terminals. EFFECT: enhanced braking efficiency. 4 cl, 2 dwg |
