Power Cable Intermediate Connection Structure with Variable Thickness Sleeve
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Solution Overview
Problem
The existing intermediate connection structures for power cables suffer from heating issues due to a small current supply path area between conductors connected through a joint box, leading to increased thickness of the conductor sleeve, which in turn increases the size of the joint box and complicates submarine cable installation.
Innovation Solution
An intermediate connection structure with a conductor sleeve having multiple steps on its inner surface, matching the step-wise diameter reduction of the conductors, and a partition wall at the center, which minimizes the diameter of the conductor connection part and reduces heating by optimizing the current supply path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the thickness of the conductor sleeve is increased to prevent heating, then the heating problem is solved, but the thickness of the reinforcing insulating layer must be increased and thus the whole size of the joint box or intermediate connection structure increases
Solution Approach 1:
The conductor sleeve is designed with variable thickness where the central portion has a greater thickness than the end portions. This local quality variation concentrates the current supply path area increase at the heating-prone central region without proportionally increasing the overall sleeve dimensions, thereby preventing heating while minimizing the increase in joint box size.
Solution Approach 2:
Instead of uniformly increasing the sleeve thickness in all regions, the invention varies the thickness in the radial dimension at different axial positions. This dimensional approach allows the current supply path area to be increased where needed (central region) while keeping the end regions compact, thus resolving the contradiction between preventing heating and minimizing overall size.
2Reliability
If the thickness of the conductor sleeve is increased to secure the current supply path, then the current supply is improved, but the outer diameter of the flexible joint increases
Solution Approach 1:
The conductor sleeve features localized thickness variation with the central portion being thicker than the ends. This ensures adequate current supply path area at the critical central region where heating occurs, while maintaining a compact outer diameter at the end portions, thus preserving flexibility and minimizing joint diameter without compromising current supply reliability.
Solution Approach 2:
The conductor sleeve is effectively segmented into different thickness zones along its length - a thicker central zone for current supply and thinner end zones for flexibility. This segmentation allows the current supply path to be secured in the critical region without proportionally increasing the overall outer diameter of the flexible joint.
3Reliability
If a general joint box is used for connecting submarine power cables, then the connection is secure, but the joint box is large in volume and is not flexible, requiring intermediate connection in units of unit lengths which significantly increases time and costs
Solution Approach 1:
The invention employs a flexible intermediate connection structure with a conductor sleeve that has a compact design. The variable thickness configuration (thicker center, thinner ends) provides structural integrity for secure connection while enabling flexibility for continuous winding around ship turntables, eliminating the need for unit-length intermediate connections and reducing installation time and costs.
4Area of stationary object
If the thickness of the conductor sleeve is increased uniformly, then the current supply path area is increased, but the diameter of the conductor connection part increases
Solution Approach 1:
The conductor sleeve is designed with non-uniform thickness where the central portion has greater thickness than the end portions. This local quality variation increases the current supply path area specifically at the central region where current flow is most intensive, without proportionally increasing the overall diameter of the conductor connection part, thus maintaining compact dimensions while ensuring adequate current supply.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces heating at the interface between conductors, enhances connection reliability, and minimizes the thickness of the reinforcing insulating layer, allowing for a flexible joint with an outer diameter similar to the power cables, facilitating continuous winding and reducing installation costs.
Implementation Method 1
conductors of a pair of power cables may be connected by inserting the conductors into both ends of the conductor sleeve and compressing an outer circumferential surface of the conductor sleeve
Implementation Method 2
The conductor sleeve 212 and the conductors 11a and 11b may be compressed to cause outer circumferential surfaces of the conductors 11a and 11b and an inner circumferential surface of the conductor sleeve 212 to be in surface contact with one another
Implementation Method 3
an area of the current supply path P may be determined by a thickness of the conductor sleeve 212 in a region A, which is a boundary area between the conductors 11a and 11b, in the current supply path P of FIG. 22. However, as shown in FIG. 22, the area of the current supply path P determined by a cross-sectional area or thickness of the conductor sleeve 212 in a region A, which is boundary area between the conductors 11a and 11b, is small compared to the areas of the conductors 11a and 11b, and thus a heating problem may occur
Data Source
AI summary
The present disclosure relates to an intermediate connection structure of a power cable, which is capable of reducing heating of a connecting part of conductors of a pair of power cables connected through a joint box, enhancing a connected state of the conductors, and minimizing a diameter of the conductor connection part.