Power cables for aerostats

Abstract

The present invention proposes a power cable for aerostats with good mechanical performance and long service life. The structure of the cable consists of a cable core, a non-metal reinforcement, a middle sheath, a lightning discharge layer and an outer sheath from the inside to the outside; The cable core is composed of three aviation power conductors twisted together and an insulating inner sheath, which is used to protect the power conductors; the non-metallic reinforcement is stranded by insulating materials, and its twisting pitch is larger than that of the power conductors The self-stranded pitch; the middle sheath is a cylinder made of insulating material, the lightning discharge layer is a good conductor with a grid structure, the outer sheath is a semiconductor, and the outer sheath is made of the same base material as the middle sheath. The meshes of the mine layer are tightly bonded together, so that the whole cable becomes a firm whole. The power cable for aerostats of the present invention can be applied to supply power to aerostats such as tethered balloons and airships, and can also be applied to other occasions such as ship towing systems.

Description

technical field [0001] The invention belongs to the technical field of power transmission equipment, and in particular relates to a power cable for an aerostat. technical background [0002] The mooring cable of the aerostat requires high tensile strength (required working tension 100kN, breaking tension 250kN), strong pressure resistance (side pressure resistance 24kN / 100mm), and can provide a grounding path for a lightning current less than or equal to 200kA. The weight is also required to be as small as possible. The power cable used for the aerostat is one of the mooring cables for the aerostat. Firstly, it is required that the tensile force reach the established index, and it can be retracted and retracted repeatedly, and the overall consistency is good; secondly, it is required to protect the power wire, which is to ensure the aerostat The smoothness of the power transmission system of the aerostat is a prerequisite for the smooth completion of the task of the aerosta...

AI Technical Summary

Problems solved by technology

With such a design of the outer structure of the cable core, first of all, there is a polyester tape between the outer sheath and the lightning discharge layer, and the integrity of the product is damaged. When the outer sheath is subjected to a huge working pressure or tension, because it cannot get The support of other parts of the cable, so it is easy to break; secondly, the lightning discharge wire is unidirectionally twisted outside the non-metallic external reinforcement, and its tensile strength is not strong, and it is easy to break when it is subjected to a strong external force

According to experimental observations, after about 100 times of retracting and unwinding, the outer diameter of this type of power cable shrinks, and problems such as breakage of the lightning discharge wire and tearing of the outer sheath occur.

In addition to the above-mentioned problems of low mechanical strength, this type of power cable has no effective barrier between the lightning discharge wire and the non-metallic external reinforcing material, so when it is struck by a strong lightning, the strong current passing through the lightning discharge wire may also be damaged. Non-metallic external reinforcement materials, which affect the safety of the cable core

[0004] like figure 1 It can be seen that the power conductors in the core of this type of power cable are manufactured in the form of multiple small cross-sectional single power conductors co-twisted. The purpose of this design is to reduce the total calorific value by sharing the current equally among the conductors. However, due to the large resistance of a single power conductor with a small cross-sectional area, and because it is difficult to achieve a uniform distribution of current among the conductors, this type of product often has a high actual heat generation.

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