| 摘要 |
<p>PURPOSE:To certainly protect a device, by detecting an abnormal state immediately with a cast contactor at the time of the short circuit trouble of the arm of an inverter bridge, and by interrupting DC power-supply input. CONSTITUTION:On the input side of an inverter unit, is concerned, to a series circuit of a current collector 1, a fuse 2, a line breaker 3, and a DC reactor 4. The DC reactor 4 is connected to a shunt circuit 8 and to a charging resistor 5 for a filter capacitor 7. The GTO thyristor 6 of a charging switch is set in parallel with the resistor 5. A three-phase bridge circuit 12 and a DC transformer 17 are arranged in parallel with the filter capacitor 7. To a controlling power source 22, the photo-coupler 26 of an arm short-circuit detecting circuit 24 is connected via the auxiliary contact 21 of the line breaker 3, and the input of the output of the DC transformer 7 to said detecting circuit 24 is also provided. As a result, so far as the detecting circuit 24 is concerned, by a line breaker releasing sequence circuit 29, the line breaker 3 is driven, and by a GTO thyristor gate logical-circuit 30, the thyristor 6 is driven, respectively.</p> |
