RU95167U1 - POWER CABLE (OPTIONS) - Google Patents

Abstract

The utility model is aimed at increasing reliability and increasing the service life of power cables with PVC sheath. The specified technical result is achieved due to the fact that the power cable contains n insulated conductive cores with belt insulation of polyvinyl chloride plastic compound with armor and a sheath of polyvinyl chloride plastic compound. The armor is made in the form of a symmetrical braid of fibers from ultra-high molecular weight polyethylene. According to the second variant, the indicated technical result is achieved due to the fact that the power cable contains n insulated conductive cores with belt insulation made of PVC compound with armor and a sheath made of PVC compound. The armor is made in the form of a winding of fibers of ultra-high molecular weight polyethylene, superimposed in two layers in opposite directions. 2 n.p.f., 3 ill.

Description

The utility model relates to cable technology and can be used for transmission and distribution of electricity in stationary installations.

The closest adopted for the prototype is a power cable containing n insulated conductive cores with belt insulation made of PVC compound with armor from two steel galvanized tapes with a sheath of PVC compound (GOST 16442-80).

The disadvantage of this object is the accelerated thermal aging of the polyvinyl chloride plastic compound of the cable sheath as a result of the formation of condensate on the surface of the armor tapes, the main components of which are water and plasticizer. The formation of condensate accelerates the deterioration of the mechanical properties of the polyvinyl chloride shell.

The objective of the utility model is to increase reliability and increase the service life of power cables.

The problem is solved due to the fact that the power cable, as in the prototype, contains n insulated conductive cores with belt insulation of PVC compound with armor and with a sheath of PVC compound.

According to a utility model, the armor is made in the form of a symmetrical braid of fibers of ultra-high molecular weight polyethylene. The surface density of the braid is 75-90%. Braid angle from 40 ° to 50 °, winding angle from 26 ° to 30 °.

According to the second option, the task is solved due to the fact that the power cable, as in the prototype, contains n insulated conductive cores with belt insulation of PVC compound with armor and with a sheath of PVC compound.

Unlike the prototype, the armor is made in the form of a winding of fibers of ultra-high molecular weight polyethylene, superimposed in two layers in opposite directions.

Ultra-high molecular weight polyethylene, due to the high degree of polymerization, has high mechanical strength, resistance to shock and cracking. A valuable feature of ultra-high molecular weight polyethylene is the ability to maintain high strength characteristics in a wide temperature range. Therefore, this material can perform the functions of mechanical protection of the cable.

Due to the fact that the armor is made in the form of a symmetrical braid or winding, diffusion of plasticizer vapor is ensured, which prevents the formation of condensate.

Thus, the proposed power cable ensures its reliable operation with increased service life compared to the prototype. In addition, the weight of the power cable is reduced.

To explain the described object, figure 1 shows the cross section of the power cable. Figure 2 shows the surface of the armor made by the method of symmetrical braiding. Figure 3 shows the surface of the armor made by the winding method.

The power cable (Fig. 1) consists of n aluminum or copper conductive conductors 1, on which insulation is applied 2. On top of twisted insulated conductors 1, belt insulation 3 of PVC compound is applied. Fibers of ultra-high molecular weight polyethylene 4 are superimposed on the waist insulation 3. A sheath 5 of polyvinyl chloride plasticate is applied on top of the fibers.

In the first embodiment, fibers of ultra-high molecular weight polyethylene are applied by the method of symmetrical braiding (Fig.6). The surface density of this braid is 75-90%.

In the second embodiment, the fibers of ultra-high molecular weight polyethylene are superimposed by the winding method (Fig. 7) superimposed fibers of ultra-high molecular weight polyethylene in two layers in opposite directions.

For example, the braid (figure 2) with a fiber diameter of ultra-high molecular weight polyethylene 0.20 mm, a braid angle of 45 ° and a surface density of 85%.

For example, a two-layer winding (Fig. 3) with ultra-high molecular weight polyethylene fibers with a diameter of 0.20 mm with the opposite direction of the layers with a winding angle of 28 °.

The diameter of the fibers, the angle and surface density of the braid is determined by the type and brand of power cable.

When the power cable is operating (Fig. 1), the ohmic heating of the conductive core 1 occurs, which leads to diffusion and evaporation of the plasticizer from the PVC compound. The braid 6 or winding 7 allows the plasticizer to diffuse from the inner layers of the cable to the sheath 5, followed by evaporation into the environment. Thus, the braid 6 or winding 7 is not an obstacle to the diffusion process of the plasticizer and condensation does not form on it. As a result, the aging process of the polyvinyl chloride sheath 5 is slower and the service life of the power cable is increased. During overloads, short-term temperature increases of the conductive core 1 are possible, which significantly accelerate the aging process. The presence of a braid 6 or a winding 7 of fibers of ultra-high molecular weight polyethylene, which does not impede the diffusion of the plasticizer, smoothes out the effect of overloads on the aging process of the sheath 5 and, therefore, increases the reliability of the power cable.

Claims (2)

1. A power cable containing n insulated conductive cores with a belt insulation of polyvinyl chloride plastic compound with armor and a sheath of polyvinyl chloride plastic compound, characterized in that the armor is made in the form of a symmetrical braid of fibers of ultra-high molecular weight polyethylene, and the surface density of the braid is from 75 to 90 %, and the braid angle is from 40 to 50 °. 2. A power cable containing n insulated conductive conductors with a belt insulation of polyvinyl chloride plastic compound with armor and a sheath of polyvinyl chloride plastic compound, characterized in that the armor is made in the form of a winding of fibers of ultra-high molecular weight polyethylene, laid in two layers in opposite directions, while the angle of the winding is from 26 to 30 °.