| 摘要 |
In order to enable a DC machine to be switched from traction operation to braking operation as well as from forward running to reverse running, the inverter includes a chopper, comprising a main thyristor (H) provided with its switch-off circuit and a smoothing inductor (L), five routing thyristors (T1 to T5) and a braking diode (DF). The first and second thyristors (T1 and T2) have their anodes together connected to the smoothing inductor (L) and their cathodes connected to the terminals of the armature (I) of the machine whilst the third and fourth thyristors (T3 and T4) have their anodes connected to the terminals of the said armature and their cathodes together connected to the field winding (J) of the machine. The anode of the fifth thyristor (T5) is connected to the said field winding (J), whilst its cathode is intended to be joined to the negative terminal of the DC source and whilst the cathode of the braking diode (DF) is intended to be joined to the positive terminal of the said current source. This arrangement allows inversion, on command (E), of the current in the armature of the machine. The inverter can be used in railway power units. <IMAGE>
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