Subsea Cable Connection Layout for Shorter Floating Wind Risers

Solution Overview

Problem

Existing offshore wind farms with floating turbines face challenges in minimizing the length and cost of dynamic cables due to their exposure to dynamic stresses, which are more expensive and require larger cross-sections than static cables, leading to increased weight and installation complexity.

Innovation Solution

A subsea inter-array cable layout with discrete static cable sections and connection devices allows for dry connections above water, reducing the need for lengthy dynamic cables by using static cables that extend beyond the water depth and connecting to floating units via a single connection device, minimizing the length and cost of dynamic cables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dynamic cables are used to connect floating wind turbines to the seabed, then the cables can withstand dynamic stresses from water motion, but the cables become much more expensive and require larger cross-sections

Engineering Contradiction:

Improvecable reliabilityVSAvoidcable material quantity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The cable system is divided into two distinct segments: dynamic cables connecting floating turbines to intermediate connection devices, and static cables connecting the intermediate devices to the seabed. This segmentation allows each cable type to be optimized for its specific function, reducing overall material requirements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Intermediate connection devices are introduced as mediators between the floating wind turbines and the seabed. These devices act as transition points where dynamic cables connect to static cables, allowing the system to benefit from both cable types without requiring full-length dynamic cables

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If the cross-section of dynamic cables is increased to handle the same electrical power as static cables, then power transmission capability is maintained, but the weight and bulk of the cables increase substantially

Engineering Contradiction:

Improveelectrical power transmissionVSAvoidcable weight

Core Design Contradiction:

PowerVSWeight of moving object

Solution Approach 1:

The cable system is divided into two distinct segments: dynamic cables connecting floating turbines to intermediate connection devices, and static cables connecting the intermediate devices to the seabed. This segmentation allows each cable type to be optimized for its specific function, reducing overall material requirements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different cable specifications are used in different locations within the system. Dynamic cables with appropriate cross-sections are used only where needed to connect floating turbines to intermediate devices, while static cables with larger cross-sections are used for the seabed connections where they don't need to withstand dynamic motion

Inventive Principle:

Principle #3Local quality

3Length of moving object

If dynamic cables are made longer to accommodate deeper water and greater turbine spacing, then the cables can reach all turbines, but the cost and installation complexity increase

Engineering Contradiction:

Improvecable lengthVSAvoidinstallation complexity

Core Design Contradiction:

Length of moving objectVSDevice complexity

Solution Approach 1:

The cable system is divided into two distinct segments: dynamic cables connecting floating turbines to intermediate connection devices, and static cables connecting the intermediate devices to the seabed. This segmentation allows each cable type to be optimized for its specific function, reducing overall material requirements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The intermediate connection devices and static cables are installed on the seabed first, establishing a stable foundation before the floating turbines and dynamic cables are deployed. This preliminary action simplifies the overall installation process

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP4548438B1Connection arrangements for marine energy installations

Publication Date: 2026.03.25 ACERGY FRANCE

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AI summary

In a subsea inter-array cable layout for marine power generation installations, a series of two or more discrete sections of static cable extend in longitudinal succession along a common path. Each cable section comprises a longitudinal portion and at least one lateral portion. The longitudinal portions of the series extend along the path and lateral portions of adjacent cable sections extend laterally outwardly to the same side of the path, as a pair. Connection devices connect to each pair of lateral portions to interconnect the cable sections. The connection devices are spaced from the longitudinal portions by a distance greater than the local water depth so that outboard ends of the lateral portions can be lifted to the surface to effect dry connections without disturbing the longitudinal portions. Additionally, at least one dynamic cable extends from each connection device for connection to a floating unit such as a wind turbine.