| 摘要 |
<p>PURPOSE:To secure the normal commutation margin angel even when the control is switched for a vernier control winding, by setting the minimum ignition advance angle of a vernier control thyristor converter lager by a fixed degree than the same minimum igintion advance angle which actuates other thyristor converter. CONSTITUTION:The control circuit 12 delivers the prescribed control signal by supplying the minimum commutation margin angle signal detected by the detecting circuit 10. Then the control circuit 16 is connected between the circuit 12 and the phase control circuit 14 of the rectifiers Rec1-Rec4 to give a control to the phase control angle of the vernier control rectifier so that it becomes larger than the minimum ignition advance angle betamin by the commutation overlap angle Ualpha during a certain time in the period during which a control switching is given to the vernier control rectifier. As a result, the normal commutation margin angle can be secured even when a control switching is given to the vernier control winding.</p> |
