| 摘要 |
PURPOSE:To accurately control the firing phase by approximating the movement of a control angle command value to a rectilinear line when digitally controlling a firing. CONSTITUTION:A control angle command value, control pulse ON/OFF command and a control signal of a switching command of a thyristor bridge are received through a system input circuit 54 from a DDC (Direct Digital Control) unit, not shown. A synchronizing signal to be fed to a processor 5 and an actual control angle value from a reference point of each thyristor are applied by a synchronizing signal transformer 6 and a quantizing circuit connected with an AC power source 1. The processor 5 varies the movement of the control angle command value from the approximate due to the stepwise variation as conventional one to the approximate to a rectilinear line, thereby accurately controlling the firing phase even in a power converter which always varies the control angle as a cycloconverter. |
