| 摘要 |
PURPOSE:To eliminate neutral grounding resistor thus to reduce the size and cost of neutral grounding device by employing winding composed of high resistivity conductor as reactor winding for neutral grounding reactor. CONSTITUTION:Neutral grounded machinery is comprised of single structure neutral grounding reactor 1' and particularly reactor winding 6' is constituted by winding iron which has higher resistivity than copper. Iron has resistivity approx. six times that of copper while inductance of reactor winding 6' is substantially proportional with the square of number of turn of the winding. Since inner resistance of reactor winding 6' becomes approx. six times that of conventional one, it can be set as inner resistance having substantially requied resistance. Consequently neutral impednace required for power system can be obtained with only neutral grounded reactor 1', thereby conventional neutral grounding resistor is eliminated resulting in reduction of size of neutral grounding device. |
