GB1277952A - Gas insulated transmission line - Google Patents

Abstract

1277952 Electric couplings HIGH VOLTAGE POWER CORP 31 July 1969 [31 July 1968] 38521/69 Headings H2C and H2E [Also in Division H1] In a gas-insulated transmission line comprising inner and outer conductors, the inner conductor is insulatingly supported by means which permit longitudinal expansion of the inner conductor and maintain the conductor axes parallel. Expansion supports (E), movable supports (D) and fixed supports (F) are, used in each section of line, sections being joined in manufacture or on site. Several forms of expansion supports are described. In one, Fig. 2, adjacent ends of inner conductors IC 2 are located in recesses 47 of insulators I 2 which have metal-lined stress-relief recesses 42a, 44a. Electrical, connection between the conductors IC 2 is by flexible bands 48a and solid members. 50a, the bands bending into the recesses 44a upon expansion of the conductors. The outer conductors OC 2 are joined and sealed by sleeves C 2 , which may be split longitudinally (Fig. 4, not shown). The expansion joint may occur away from a joint in the outer conductors and the insulator (I 5 ) may be keyed thereto (70, 72), (Fig. 5, not shown). In another arrangement, Fig. 8, the ends of the inner conductors L, R are partially cut away and overlapped, being joined electrically by bowed resilient webs 96, which may be tangential to the conductor faces, or normal thereto (Fig. 10, not shown). The fixed supports may comprise annular insulators keyed to the conductors (Fig. 11, not shown) or part insulators bolted to the conductors, the inner conductor being flattened on one side and slotted on the other so as to receive electrostatically-deposited dust, (Fig. 12, not shown). The movable support may be bolted to the outer conductor and connected to the inner conductor by flexible members (Fig. 13, not shown), may comprise part insulators bolted to the inner conductor and having rolling engagement with the outer conductor, (Fig. 14, not shown), or may comprise annular insulators keyed to the inner conductor and having spring- pressed rollers engaging the outer conductor (Fig. 15, not shown). The insulators may be of glass, ceramic or epoxy, and the inner conductor may have a layer of such material. The outer conductors may be cross-connected and connected to earth to avoid stray currents.