| 摘要 |
PURPOSE:To enable the operation to be stable even when the distortion is caused in the voltage of an AC system by taking out only the vibrating voltage component of the AC system voltage, smoothingk said voltage, and enlarging the control lead angle of the power inverter. CONSTITUTION:In the case the power inverter C is controlled in DC power transmission, the voltage of the AC system is taken out from transformers PT1-PT3, applied to a rectifying bridge comprising diodes D1-D12 through filters F1-F3, and smoothed. Then, its output is added to the output of an excess angle control circuit AD in an adder including an operation amplifier A1, thereby each thyristor in the power inverter C is controlled via a pulse phase shifter AP. Therefore, only the vibrating voltage component of the system voltage is taken out and smoothed, the control lead angle can be enlarged corresponding to the said voltage even when the distortion is caused in the waveform of the AC system by the opening and closing of a stable capacitor SC and the like, and the excess angle as in the normal operation can be secured, thereby the stable operation can be performed. |
