| 摘要 |
<p>PURPOSE:To protect a GTO chopper by controlling the armature coil current and field coil current of a shunt motor by the chopper using a GTO, and suitably controlling the chopper when the voltage of a filter capacitor of input side becomes the prescribed value or higher. CONSTITUTION:A trip coil 19 of a high speed breaker 26 is provided between an anode reactor 28 and a high speed breaker 14. Signals are respectively outputted from ON pulse gate circuits 43, 44 to field choppers 29, 32. When the fact that the voltage of a filter capacitor 15 is the prescribed value or higher by a comparator 38 by a signal from a detector 22, a GTO24 for an armature chopper is turned OFF, GTOs 29, 32 for field chopper are not turned OFF but remain in conducted state.</p> |
