GB742554A - Improvements relating to high-voltage instrument transformers - Google Patents

Abstract

742,554. Transformers. REYROLLE & CO., Ltd., A., and MOSER-GLASER & CO., AKT.-GES. July 9, 1953 [July 15, 1952], No. 19125/53. Class 38 (2). A high voltage transformer has current transformer windings at least partly embedded in a closed end of a hollow synthetic resin insulating member of tubular shape, the insulating member having potential gradient control means at least partly embedded in the walls of the' insulating member. A synthetic resin insulating body 1 has the core 5 and the primary and secondary windings 3, 6 of a current transformer embedded in the closed end of the insulating member. The potential gradient control means is formed by the secondary winding 8 of a potential transformer, the core 10 of which is housed in the bore of the insulating member, the primary winding 11 of the potential transformer being wound around the core 10, the core being flanged at the bottom end to reduce the length of the air part of the magnetic circuit. The insulating member is provided with electrically conducting coatings 12, 13 the the outer 12 of which is connected to the end of the secondary winding 8 of the potential transformer. Weathersheds 9 are provided which may be integral with the insulating member 1. The potential gradient control means may alternatively comprise overlapping eylindrical condenser plates embedded in the walls of the member 1 or a series of high ohmic resistor so embedded may be used. Various embodiments of the current transformer assembly are described having either or both of the primary and secondary windings embedded, the core' projecting into a transverse hole in the closed end of the insulating member, or the primary winding may be of a straight through bar-type. The insulating member is preferably manufactured by a centrifugal casting process forming the subject of Specification 742,413.