| 摘要 |
<p>A method of forming a joint in an optical line that extends along a phase conductor (1) of a high voltage overhead power transmission system, comprises: (i) forming a length of optical cable (10) which comprises a plurality of optical fibres; (ii) encapsulating the optical fibres; (iii) providing an intermediate region of the length of optical cable with an outer, non-tracking jacket (12) so that a part of the length of optical cable extends from each end of the outer, non-tracking jacket; (iv) installing the jacket so that it extends between phase potential and any other potential to which the cable will be subjected; and (v) connecting one end of the optical fibres of the optical cable to fibres in the optical line of the phase conductor (1), and connecting the other end of the optical fibres of the optical cable to another optical line. The parts of the length of the optical cable that extend from each end of the outer, non-tracking jacket (12) have a sufficient length that connections can be formed between the optical fibres and the optical lines at points remote from regions in which the cable extends along high electrical field gradients. This has the advantage that the optical fibres of the assembly which, in use, will extend between the potential of the phase conductor and earth can be encapsulated in the factory under controlled conditions, and conventional means may be employed to connect the cable.</p> |
