| 摘要 |
<p>PURPOSE:To prevent dielectric breakdown failure and improve reliability even if grounded end of a high voltage winding is opened by mistake when high voltage is applied to the high voltage end of the high voltage winding by providing and electrically connecting a capacitor element having a capacitance larger than one on the side of the high voltage end of the high voltage winding with respect to the ground between the grounded end of the high voltage winding and the ground. CONSTITUTION:A high voltage winding 27 is wound coaxially with a low voltage winding 22 around the outer periphery of a capacitor element 26 and electrically connected at its grounded end 27b to the outer foil 25b of the capacitor element 26. Herein, capacitance C2 of the capacitor element 26 is adjusted in the areas of the outer foils 25a, 25b and the thickness of an insulating material 24 such that said capacitance C2 is sufficiently greater than capacitance C1 existent between the high voltage end 27a of the high voltage winding 27 and the outer foil 25b. Hereby, even when the grounded end of the high voltage winding 27 is opened by mistake under a situation where high voltage is applied to the high voltage winding 27, voltage produced on the grounded end 27b of the high voltage winding 27 can be satisfactorily reduced, so that a ground type instrument transformer can be protected against dielectric breakdown.</p> |
