| 摘要 |
PURPOSE:To simplify a control circuit, in a tap changer which adjusts voltage through V-connection of transformer and tap change in two phases with phase control, by changing capacity of current limiting element of each phase and equalizing influence on changing element by a bridging current. CONSTITUTION:A control angle of thyristor is detected by a control angle detection circuit 84 and the timing of tap change signal is obtained by a tap changing circuit 85. Next, a signal is given to a pulse transformer 87 through pulse-up 86 and an ignition signal is applied simultaneously to the thyristors 88 and 89 of phases U and W of changed tap. Thereby only one control circuit 53 is used, in place of the independent control of each phase and a number of pulse transformers are also reduced to a half, pulse transformers 41-45. Where capacity of current limiting elements 71 and 72 is changed so that influence of bridging current on the elements is equalized for each phase, simultaneous control of phase U and W can be realized. Therefore, when information of the one phase is detected, tap change can be realized by a half number of control circuits and pulse transformers. 81 is PT, 82 is rectifing circuit, 83 is tap determination circuit. |
