Measuring transformer for a fully insulated, metal-clad high-voltage installation

A measuring transformer for a fully-insulated, metal-clad, high-voltage installation equipped with a metal outer tube containing a high-voltage conductor comprising:

• a tube member arranged within and spaced from the metal outer tube of the high-voltage installation and in surrounding relation to the high-voltage conductor, said tube member constituting a surface-type electrode and, said tube member and the high-voltage conductor conjointly defining a high-voltage capacitor;
• a low-voltage capacitor connected to said high-voltage capacitor so as to conjointly define therewith a capacitive voltage divider;
• a transformer core unit including an iron core, and a secondary winding system mounted on said iron core, said transformer core unit being arranged on the outer surface of said tube member whereby said tube member carries said transformer core unit inside the metal outer tube of the high-voltage installation;
• first mounting means at one end of said tube member for attaching the same to the metal outer tube so as to be insulated therefrom;
• and second mounting means at the other end of said tube member for supporting said tube member with respect to the metal outer tube so as to be insulated therefrom, said first mounting means comprising a fastening shoulder at said one end thereof, a fastening projection extending from the inner wall of the metal outer tube, a connecting member made of insulating material for connecting said fastening shoulder to said fastening projection, and first and second screw means for connecting said connecting member to said fastening shoulder and to said fastening projection respectively;
• and said second mounting means comprising a fastening shoulder extending from said tube member at said other end thereof, a supporting element for supporting said tube member with respect to the metal outer tube;
• and screw means for connecting said supporting element to said last-mentioned fastening shoulder.

A measuring transformer for a fully-insulated, metal-clad, high-voltage installation equipped with a metal outer tube containing a high-voltage conductor comprising:

• a tube member arranged within and spaced from the metal outer tube of the high-voltage installation and in surrounding relation to the high-voltage conductor, said tube member constituting a surface-type electrode and, said tube member and the high-voltage conductor conjointly defining a high-voltage capacitor;
• a low-voltage capacitor connected to said high-voltage capacitor so as to conjointly define therewith a capacitive voltage divider;
• a transformer core unit including an iron core, and a secondary winding system mounted on said iron core, said transformer core unit being arranged on the outer surface of said tube member whereby said tube member carries said transformer core unit inside the metal outer tube of the high-voltage installation;
• first mounting means at one end of said tube member for attaching the same to the metal outer tube so as to be insulated therefrom;
• second mounting means at the other end of said tube member for supporting said tube member with respect to the metal outer tube so as to be insulated therefrom, two protective ring electrodes, each of said ring electrodes being configured as a tubular part, said tubular parts being mounted at respective longitudinal ends of said tube member so as to be electrically insulated therefrom, one of said tubular parts being mounted on said tube member at one end thereof, and the other one of said tubular parts being mounted on said tube member at the other end thereof;
• said first mounting means comprising a fastening shoulder extending from said tube member on said one end thereof, a fastening tab extending from said one tubular part, and a fastening projection extending from the inner wall of the metal outer tube, a connecting member made of insulating material for connecting said fastening shoulder to said fastening projection, and insulating clamping means for clamping said fastening tab to said fastening shoulder and to said connecting member so as to insulate said shoulder from said tab, and means for connecting said connecting member to said fastening projection;
• and said second mounting means comprising a fastening shoulder extending from said tube member at said other end thereof, a fastening tab extending from said other one of said tubular parts, a supporting element for supporting said tube member with respect to the metal outer tube, and insulating clamping means for clamping said last-mentioned fastening tab to said last-mentioned fastening shoulder and to said supporting element so as to insulate said last-mentioned shoulder from said last-mentioned tab.