| 摘要 |
<p>PURPOSE:To improve the riding feeling of a vehicle when the voltage of a trolley wire abruptly varies and to protect the armature from burning out by connecting means for detcting reverse current flowed through the armature and means for opening an armature circuit when the detected current value becomes the set value or higher in series with the armature circuit. CONSTITUTION:A current which flows through an armature 4 and a shunt field 7 is controlled by an armature chopper 5 and a field chopper 8 which respectively have conductivity in positive and negative directions. Then, a DC current transformer 28 for detecting the reverse current flowed through the armature 4 and a breaker 29 for opening the armature circuit when the detected current value exceeds the set value are connected in series with the armature 4. In this manner, the riding feeling of a vehicle when the voltage of a trolley wire abruptly varies is improved, and the affecting phenomenon when a motor becomes defective can be prevented.</p> |
