| 摘要 |
A self-controlled polyphase bridge type inverter utilizes controllable valves of the semi-conductor type such as thyristors in the branches of the bridge, the bridge being fed from the output of a rectifier by way of an intermediate d.c. voltage link circuit that includes at least one smoothing condenser and at least one smoothing inductance. In the event of a through-going ignition i.e. a mal-function in the inverter all controllable valves of the inverter including load valves and/or any auxiliary valves are activated simultaneously by an ignition pulse so that the smoothing condenser together with such inductances as are included in the inverter form an oscillating circuit while the valves are simultaneously ignited. In order to protect the inverter structure under such a condition, a diode in series with a resistor is connected electrically in parallel with the smoothing condenser, the diode being wired in the blocking direction relative to the normal polarity of the d.c. voltage link circuit and providing an electrically conductive connection between the poles of the smoothing condenser after the change in polarity of the condenser caused by the oscillation process beginning with the second half-cycle of the voltage.
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