| 摘要 |
<p>PURPOSE:To reduce the cost by utilizing the charge of a filter capacitor to rise a generating brake current, thereby simplifying the circuit. CONSTITUTION:Brake circuit contactors 14-16 and a shortcircuiting contactor 17 are opened at power drive operating time, a breaker 2, an input contactor 4 and a power drive contactor 13 are closed, and a DC power supplied from a trolley wire to DC motor group is controlled by a chopper formed of a filter capacitor 6, a freewheel diode 8, and a chopper 7. The breaker 2 and the contactor 4 are opened at generating brake operation time, and the contactor 13 is opened. Then, when the contactor 14 is closed, charge stored in the capacitor 6 is discharged through a field winding 11F, and the generating brake current rises. Thereafter, the conduction rate of the chopper 7 is controlled to control the brake force.</p> |
