| 摘要 |
PURPOSE:To conduct switching operation or switching and switchback operation without interruption by connecting a variable cross-current suppression impedance in parallel with a loop-point switch and detecting a current flowing through this cross-current suppression impedance and the both side voltage of the loop- point switch and by controlling the magnitude of the cross-current suppression impedance on the basis of the detected values. CONSTITUTION:The both side voltage V of the normally open loop-point switch SS20 of a loop-switching arrangement 20 is stored in a control circuit 20-10. Further, a cross current Ic1 at the time of inserting the suitable value Zc1 of a cross current suppression impedance Zc is also stored in the control circuit 20-10. After the optimum value Zc0 is obtained by the use of these values, the cross-current suppression impedance Zc is set to Zc0. Then, after a switch 20-7 and the loop-point switch SS20 are closed, section switches SS12, SS11, are opened. In this manner, it is possible to cut off the power supply to the second section S12 and to supply electricity to a third section S13 without interruption. |
