Improvements in and relating to earthing choking coils or voltage transformers for high voltages

摘要

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' - - w4 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 j4, 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.