LOW-VOLTAGE WINDING FOR AIR-COOLED RESIN-INSULATED DISTRIBUTION TRANSFORMERS

摘要

Such windings are normally wound spirally from sheet-metal strip (15) of the same width as the axial winding length and with intermediate layers of plastic film or resin-soaked fabric (16) projecting on all sides, and are cast with a resin ring (17) on each of the end faces, terminal leads welded onto the sheet-metal strip and consisting of conductor rails (18) with a rectangular cross-section being bonded by means of their broad side to the coil over the full width of the sheet-metal strip (15). According to the invention, at least the terminal lead located inside the winding tube (5) engages at least on its end guided out of the coil into the adjacent resin ring (17), via the armature (19), the resin ring (17) being reinforced (20) at least in the region of each armature (19). This design of low- voltage windings (5) provides a design of resin-insulated distribution transformers which is particularly more resistant to short-circuits and extends their possible applications to even greater rated powers than in the past.