GB173759A - Improvements in and relating to earthing choking coils or voltage transformers for high voltages - Google Patents

Abstract

173,759. Pfiffner, E. Jan. 5, 1921, [Convention date]. Transformers, - In an earthing-coil or voltage transformer for high-voltage lines, the high-voltage winding is distributed over a number of separate iron cores, which are insulated from earth and connected to different points of the winding. In the arrangement shown in Fig. 1, the high-voltage conductor a is earthed through the windings w' - - w<4> mounted on the cores j1, - - j4, each of which is connected to the corresponding windings through high-ohmic resistances r, - - r4. The connections between the cores and windings may be made through condensers, which may be constituted by the windings and the surfaces of the cores. Conducting-screens c1 - - c3, connected to the windings through high-ohmic resistances or condensers, may be placed between the windings and the casing b in order to graduate the fall of potential in the insulating-material filling the casing. A secondary winding s connected to a measuring-instrument, leakage indicator, or the like may be mounted on the core j<4>, as shown, or all the cores may be provided with secondary windings connected in series. Each core and winding may be mounted in a separate casing and a number of such casings b1 - - b4 may be placed one on the other to form a chain insulator, as shown in Fig. 2. In this arrangement each casing is closed by insulating-covers e1 - - e4, and the ends of the windings are connected to conducting- mounts f. The casings may be provided with rain covers d1 - - d4 of conducting or insulating- material.