Abstract: A circuit arrangement for large power transformers with a low-voltage winding, a main high-voltage winding and a step winding as well as a step switching device at a Y-point side thereof, includes, at a location between a point connecting the step winding to the high-voltage main winding and the Y-point of the transformer, a capacitor in series with a resistor is connected electrically parallel to respectively current-carrying steps of the step winding, the capacitor and the resistor being of such dimensions as to decrease resonance amplitudes of the connecting point to ground, the capacitor being constructed of spirally wound strip lines formed of a resistance alloy, the strip lines being also of such dimensions as to reduce resonance amplitudes of the connecting points.

Abstract: Method of manufacturing a transformer winding embedded in casting resin by winding coils respectively by themselves and independently of one another for disposition thereof in tandem in axial direction of the winding includes placing the wound coils in a substantially annular casting mold having an inner and an outer jacket, with respective impregnated corrugated mats of insulating material as spacers disposed between the inner jacket and the coils as well as between the coils and the outer jacket, the inner and the outer jackets being fixed between mold end walls at respective ends of the casting mold; and disposing the casting mold containing the wound coils in an evacuated chamber and pouring casting resin into the casting mold through an axially parallel slot formed in the outer jacket thereof.

Abstract: Disk coil winding formed of interwound single or double coils wherein insulation of outer turns opposite inner and outer generated surfaces, respectively, of the winding is reinforced in comparison with normal insulation of conductors of the winding including auxiliary insulations angularly surrounding at least one edge of at least two turns, respectively, in at least the coils disposed at an input of the winding, starting from the inner and the outer generated surface, turn capacitance between turns free of auxiliary insulation being increased with respect to turn capacitance at turns provided with the auxiliary insulations.

Abstract: Transformer having an active part thereof disposed in an oil-filled, smooth-walled tank having side walls braced by ribs secured by welding and subdivided into wall-high panels, the panels, respectively, including a sheetmetal wall having a resonance frequency f.sub.o smaller according to the function f.sub.o =(S.multidot.k.sub.f)/B.sup.2 then twice line frequency, wherein S is the thickness of the sheetmetal in cm, B the net panel width in cm, and k.sub.f a constant having an absolute magnitude which depends upon the length-to-width ratio of the panel, upon the modulus of elasticity, upon the transverse contraction and upon the specific gravity of the material used therefor.

Abstract: Transformer, including an iron core, high voltage and low voltage windings, at least one cast resin body completely embedding, holding and insulating the windings, the cast resin body having cooling channels formed therein and having additional channels formed therein being separated from the cooling channels, and insulating gas filling the additional channels.

Abstract: A disc coil winding of interwound coils is formed of winding conductors covered with normal insulation, the winding having a radially inner and a radially outer surface. A plurality of the coils are disposed at an input to the winding, and have respective turns thereof located at the inner and the outer surface of the winding as well as respective turns thereof located radially adjacent thereto. Supplemental insulations are provided for reinforcing the normal insulation, the supplemental insulations extending from respective starting locations both between the turn located at the inner surface and the turn adjacent thereto as well as between the turn located at the outer surface and the turn adjacent thereto for protecting at least one edge of the respective turns. The coils have a turn capacitance between respective turns thereof free of the supplemental insulations which is greater than the turn capacitance between the respective turns thereof provided with the supplemental insulations.

Abstract: Liquid-cooled transformer for large power ratings, including a tank having a bottom with cutouts formed therein, large-area base plates resting on the bottom of the tank, an active part having ends and a pressure device being fastened to the base plates, at least one of the base plates being disposed under one of the ends of the active part, the at least one base plate having outside corners being disposed above the cutouts formed in the tank bottom, stopping blocks positively locking the outside corners in position without play, and inserts supporting the stopping blocks and oil tightly closing off the cutouts.

Abstract: Liquid-cooled transformer for large power ratings, including a tank having a bottom, large-area base plates resting on the tank bottom, an active part and a pressure device fastened to the base plates, a plurality of synthetic resin-filled cups disposed in the tank bottom, a post supported by and projecting downward from the base plates being immersed in each of the cups for horizontally locking the base plates relative to the tank bottom.