| 摘要 |
PURPOSE:To stably execute switching between converters by selecting the AC voltage in the converter which is controlled continuously by phase at higher voltage than that in the converter which is controlled by ON-OFF. CONSTITUTION:The number of turns on the secondary winding NS1 in a transformer Tr is composed of more turns than NS2 (about 1 to 0.8) and first of all, the firing control angle alpha1, of a rectifier Pf1 is continuously controlled in the zero degree direction from pi at point A and when the firing control angle reaches the minimum firing control angle alphaM at point B, the firing control angle alpha2 of a rectifier Rf2 is rapidly changed to zero degree from pi and the firing control angle alpha1 of the rectifier Rf1 is simultaneously and rapidly changed up to pi from the minimum firing control angle alphaM in the reverse direction. Therefore, developed voltages at the secondary windings Ns1, Ns2 of the transformer are low in Ns2 by C-B. So, sudden changes in load current and voltage will not exist even if such a change in firing control angle is experienced at the point B and the switching between converters will stably be executed. |
