Influence of OPGW Optical Cable Short Circuit Current on Optical Cable
The instantaneous high temperature does not pose a serious threat to the buffered and protected optical fiber, but the tensile strength of aluminum and aluminum-magnesium alloys begins to decrease after exceeding 140 °C, and irreversible plastic deformation will occur under tension after exceeding 200 °C. If the plastic deformation is irreversible, the OPGW optical cable will be damaged, and the sag of the OPGW will increase on the line, which will affect the safe distance from the wire, which will affect its service life.
Secondly, if the anti-corrosion ointment used in the outer layer of the OPGW burns locally, it is difficult to be sure that the anti-corrosion of the metal itself can meet the long-term safe operation for decades because the OPGW is erected in the field all the year round and is subjected to various environmental influences. , and coating anti-corrosion ointment on the metal surface is a method commonly used by OPGW.
If the flash point of the ointment is lower than the instantaneous high temperature caused by the short-circuit current, the OPGW will not be able to obtain the anti-corrosion protection of the ointment after the short-circuit current passes, which will directly affect the service life, so the flash point and overvoltage temperature of the anti-corrosion ointment must be certain to match.
The premise of safe and reliable operation of OPGW is that its structure and technical characteristics must meet the conditions of use of power ground wires in power lines. Since OPGW uses optical fiber units, the structure of ground wires has been changed, and the design structure of OPGW must not only meet the requirements of communication It can also meet the needs of the system to withstand the current required by the line design for a certain period of time when the system is short-circuited (generally take a single-to-ground short-circuit). The short-circuit current test is to obtain key indicators that reflect this requirement.
