| 摘要 |
<p>PURPOSE:To reduce split secondary winding numbers, by combining a transformer having a plurality of secondary windings and a semiconductor converter, and by changing voltage of windings connected to unit converters which is phase controlled at high and low regions of converter output voltage. CONSTITUTION:An AC power source 1 is connected to a primary winding of a transformer 3 via a reactor 2. A secondary winding of the transformer 3 is divided in five. Each of windings 31, 32, 33, 34, 37 is connected to each of unit converters 41, 42, 43, 44, 47 constituting a thyristor converter 4. The converters 41, 42, 43, 44, 47 are connected in series. A load 6 is connected to them via a smoothing reactor 5 at a DC output. The secondary winding ratio of transformer 3 is set lower for the windings 31, 32 in voltage ratio and higher for the winding 37. The converters 41, 42, 43, 44, 47 are controlled sequently in phase in correspondence with composite output voltage of the converter 4. The converters 41, 42, 43, 44, 47 are controlled to constant margine angle at regenerative operation for inverse conversion. This reduces the split secondary winding numbers of transformer 3 and realizes more stable regenerative operation without increasing the maximum high-frequency current at the power supply.</p> |
