| 摘要 |
PURPOSE:To enhance safety remarkably by providing a current transformer with two sets of primary windings connected so that current flows differentially through each element group thereby preventing short circuit of capacitor which may cause explosion or eruption of oil. CONSTITUTION:Element groups 1, 2 in a capacitor comprises a plurality of elements connected in series and when a part of elements is damaged and short- circuited, the capacitance varies to cause variation of ripple current or pulse current produced through charge/discharge of the capacitor. Since currents of the element groups 1, 2 flow differentially through two sets of primary windings of an incorporated current transformer 3, current of the element group 1 exceeds the current of the element group 2 upon breakdown and short circuit of a part of elements in the element group 1 and they are not canceled each other in the current transformer 3 and thereby a current and a voltage are induced in the secondary winding. Thus induced current and voltage are detected by a relay 11 which then produces a contact signal for opening a power supply. |
