| 摘要 |
PURPOSE:To permit a sudden change of a phase angle by deciding an element to be turned on and OFF for obtaining a difference in size between a waveform synchronized with an AC system voltage waveform and a signal indicating an operating phase of a power converter. CONSTITUTION:A self-arc-extinguishing-type power converter 2 consists of GTO elements Gu-Gz to carry out power conversion between an AC system 1 and a load 3. this power converter 2 is provided with a control device 4, a phase control circuit 5 and a gate circuit 6 so as to be phase-controlled according to a phase instruction manipulated variable c. Also, the phase control circuit 5 is composed of a detection circuit 7 sensing a line voltage of the AC system 1, a serration wave-forming circuit 8 forming a serrate wave W simultaneously with this AC signal F, an adder circuit 9, a control decision circuit 10 and a gate signal-forming circuit 11. In this way, a signal difference from a phase control signal given on the basis of the AC system 1 is obtained simultaneously with said system 1 and a gate signal corresponding to this signal difference is given to each of GTO elements Qu-Qz and controlled within the range of 0 deg.-360 deg. phase angle.
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