| 摘要 |
<p>PURPOSE:To enable to control stable suppression of the speed of an electric railcar by connecting a generating resistor in parallel with a main motor when a regenerative load is less, separating the main circuit from a trolley wire, and controlling the conduction rate of a field chopper to the value corresponding to a speed suppressing notch. CONSTITUTION:When a regenerative load is less or is interrupted at the suppressing speed brake controlling time, a thyristor 10 is fired to connect an overvoltage suppressing resistor 9 in parallel with a main motor as a generating brake resistor. Then, a switch 3 is turned OFF to separate the entire main circuit from a trolley wire wheel 1. At this time, the conduction rate of a field chopper 8 is fixed to the value corresponding to the speed suppressing notch. In this manner, stable speed suppressing control can be performed, and even when the power of the trolley wire is interrupted, the speed suppressing control can be performed.</p> |
