| 摘要 |
<p>The trackside control includes a trackside d.c. power supply applied initially at low voltage (of selectable polarity, to determine the direction of motion of the locomotive along the track) and then increased (preferably with constant voltage-increase rate) to maximum supply voltage, and a trackside electrical braking load (preferably capable of forcing down at constant rate the voltage applied to it from the vehicle motor). The motor has series and (separately excited) shunt field windings (Se, Sh) and on-board sensing and switching circuitry (D1, D2, PC1, PC2, SFC1, D3. BCR, SFC2) which: (a) in motoring, either forward or reverse, sets full series field in flux addition to limited shunt field; (b) in coasting, maintains field winding switch settings; and (c) in electrical braking, sets full shunt field and reduces the now decompounding series field.</p> |
