OPPC is a new type of special power cable after ADSS and OPGW. OPPC integrates optical cable and power transmission functions into one, which can realize optical fiber communication while meeting the normal power transmission function. Because OPPC optical cable and common power special optical cable has many advantages, at present in the power system has been increasingly concerned and gradually began to use. Expert analysis points out that OPPC is to use the corridor resources and tower resources of a transmission line to build fiber optic cables along the power line. Compared with conventional wires and common fiber optic cables, the material cost can be saved by 10-20% and the construction cost can be saved once. Accordingly, have comparative technology economy advantage.

        OPPC fiber composite phase line is a new type of power special optical cable, is the fiber optic unit composite in the phase line optical cable, has the dual function of phase line and communication, mainly used for the voltage level below 110kV, suburban distribution network, rural power network. Some lines are difficult to choose other power special optical cable, and the reliability and safety of ordinary optical cable, carrier communication is difficult to ensure that OPPC optical cable can be used to solve the problem of line communication safely and reliably: 10kV, 35kV and some 66kV and other low-voltage transmission lines themselves without ground wire; Insufficient safety distance to the ground, inability to solve crossing and crossing, insufficient tower and pole strength, frequent lane change, etc.; The use of ordinary optical cable has been stolen and maintenance problems; Carrier communication is limited by climate and topography; Some transmission lines without means of communication should be utilized. In the middle and low voltage power network, especially the distribution lines below 35 kV, some of them may not be grounded, so it is impossible to install OPGW. In all power grids, only phase lines are essential. In order to meet the requirements of power monitoring or fiber optic networking, OPPC and OPGW technologies are relatively close to each other. In the traditional phase line structure, fiber optic units are added in an appropriate way to become fiber composite phase lines.

        In the tower set up between the optical cable, as well as optical cable and guide optical cable between the need for joint box connection. The connection of OPPC is the most important part of the whole project, compared with other power cables such as ADSS, OPGW connection has many different places, including the connector box installation method, connection method, etc., are much higher than other power cables requirements, at the same time, some new requirements for the connection personnel. Usually cable is not charged, so the design of the connector box does not need to consider this problem, but in the OPPC with current and communication signal is in a piece of cable transmission, so the required communication signals in the connector box connected to the level of zero potential, to high isolation voltage and signal, safely and reliably to ensure safe operation of the line.

        OPPC connection needs to separate the optical fiber unit in the running phase line, which involves the optical fiber connection and photoelectric separation technology, and has strict requirements on the connection technology and high voltage insulation. OPPC connector box, according to the use of different ways, can be divided into intermediate type and terminal type. Generally, the intermediate connector box USES "conductive non-insulating fiber box", and the terminal connector box USES "high voltage insulated fiber box". OPPC intermediate connector box and terminal connector box have special requirements, in addition to the general connector box must have the necessary characteristics, such as waterproof and moisture-proof, reasonable fixed optical cable mode, suitable fiber structure, but also must meet the power transmission wire does not have an impact, to ensure the transmission performance of optical fiber. In OPPC, since the transmitted current and optical signal transmitted by optical fiber are transmitted in the same cable, the optical signal needs to be connected to the zero potential level, so as to isolate the voltage safely and reliably and ensure the safe operation of the line. OPPC connector box adopts "high voltage isolation insulation" technology to ensure the insulation of OPPC line operation is safe, reliable and effective. Usually, the terminal connector box adopts upper and lower fusion connection to realize the safe transmission of communication signals. The middle joint box is fused to the upper joint box once. The intermediate joint box can be divided into two kinds of "support type" and "suspension type" according to the form in which it is placed on the tower.

        OPPC fiber optic cable application technology

        First, the OPPC needs to conduct a permanent current in the three-phase system, with a constant temperature. Secondly, in order to keep consistent with the sag tension characteristics of adjacent wires, the diameter, weight, section and mechanical characteristics of OPPC should be consistent with the parameters of adjacent wires as far as possible. At the same time, the dc resistance of OPPC should be similar to that of adjacent wires to avoid voltage changes at the far end and maintain a three-phase balance.

        Special insulation fittings and special joint boxes are required for erection. In the newly built low-voltage circuit, the circuit electrical specialty first determines the wire type according to the system requirements. In order to keep the mechanical and electrical properties of the two phase wires similar to that of OPPC, the same pre-twisted power hardware is required for the two-phase wires. OPPC structure selection is in accordance with the structure of the wire, with the same size of stainless steel tube optical fiber unit to replace one of the 2.5mm2 aluminum coated steel wire. Such OPPC structure selection may be very close to the electromechanical characteristics of the other two wires.

        The fiber in the fiber unit should have a certain residual length to ensure that the fiber will not be stretched in use. For OPPC, due to the structural elongation caused by lay-off, over-pulley and tight line, the expansion elongation caused by temperature rise in the operation process and creep elongation caused by plastic deformation, it is very strict with the requirements of fiber residual length. The optical fiber unit should have good mechanical protection to ensure that the optical fiber is not squeezed. In order to prevent moisture intrusion and affect the service life of optical fiber, optical fiber should be placed in a closed pipe, or take other effective moisture-proof measures. Fiber optic cable parameters to be close to the wire, optical fiber chromatography to be configured according to the standard.

        Different from OPGW, OPPC is directly installed in the high voltage system. The fittings and accessories installed by OPPC (such as tension resistance wire clip, suspension wire clip and terminal joint box) shall be insulated. The wire clip can be used for corresponding insulation tension resistance string or insulation suspension string.

        Special connector box: jumper connector box installed between two tension insulator strings is all-metal, and its effective metal conductive cross-sectional area should be greater than the cross-sectional area of the phase line. At the same time, the length of jumper is strictly controlled, and the distance between the connector box and the ground (tower material) must be controlled. Photoelectric separation is required at the line terminal, usually the terminal connector box is installed on the insulation bracket. In addition, the insulation index of the connection box and metal fittings and the corresponding tower must meet the insulation test requirements of the corresponding line voltage level.

        OPPC mounting hardware

        OPPC has a unique structure of fiber beam tube installed in its conductor, so it must be installed with pre-twisted wire fittings to protect the fiber. The use of pre-twisted wire gold has the following advantages: 1. (2). The pre-twisted wire is a good conductor, good conductivity, and the surface is flat, the end of the special treatment, improve the corona discharge voltage, energy saving effect is significant; (3) pre-twisted wire fittings installed in the line and wire contact surface increase, increase the length, uniform force, reduce the fatigue of the wire, prolong the life of the wire, improve the anti-vibration ability.

        As the structure performance of OPPC is similar to that of OPGW, double-layer pre-stranded metal fittings can be selected. The local pressure of this kind of metal fittings on cables is small, and the tension in the direction of cables can be dispersed to a longer area. Uniform stress distribution, no stress concentration point, can be a good protection of optical cable, but also has a greater grip and dynamic bearing capacity. This kind of pre-twisted metal tool has been used in a large number of ADSS, OPGW and high-voltage overhead transmission and substation lines all over the world, and the operation practice has proved that it has good safety, high reliability, convenient construction, fast and has the characteristics of corona filial piety light weight, magnetic loss filial piety maintenance-free, obvious energy-saving effect and so on.

        OPPC fiber optic cable application advantage analysis

        The adoption of OPPC new technology has solved the current power ADSS and OPGW optical cable electric corrosion, can not meet the requirements of crossing distance, lightning strike, theft, line loss and many other disadvantages, but more important is to the future construction of distribution network automation to provide the line optical cable channel. OPPC fiber optic cable can meet all kinds of requirements well by using transmission line path resources of power system. OPPC can also be used for wire melting ice.

        After serious reicing of transmission lines, it may cause accidents of inverted tower and broken line. In the face of snow and ice disaster, timely and effectively melting ice on the ice-covered line becomes the key to maintain the safe and stable operation of the power grid and ensure the normal power supply. 220 kv, 110 kv, 35 kv and below the line is widely adopted by thermodynamic method, melting ice, it melts the ice is will need to melt line with the same voltage grade line stringing up and in need of melting ice, three-phase short answer the end of the line and then in the 10 kv voltage applied on the road, a string of wiring used in short circuit current heat melting ice, therefore, use of OPPC cable thermal method is used to melt the ice, power transmission, communication scheduling can be better guaranteed.

        OPPC can overcome all the shortcomings of OPGW and ADSS and has a broad application prospect. Its advantages are as follows: OPPC technology is adopted to optimize the transmission line design and achieve significant energy saving effect. In recent years, our province also has OPGW lightning failure phenomenon or report. OPPC because the fiber composite in the phase line, there is no ground lightning caused by OPGW broken, broken fiber serious accident. In the renovation of the 110 kV and 220 kV old lines, due to the electrical corrosion of ADSS, fiber breakage and cable breakage, as well as the influence of the ground height of the old lines, crossing roads, railways, rivers and other natural environments, tower height and field intensity distribution should be designed.

        Compared with ADSS, OPPC does not cause the optical cable to suffer from electric corrosion or cable destruction or fiber breakage due to the effect of field strength. ADSS cable installation to the original line increased the weight, tension, additional additional line load, to the line has brought potential hidden trouble. Compared with ADSS, OPPC has no hidden trouble to add additional line load to the original line. Because OPPC and connector box have high voltage, has an absolute anti-theft advantage.