Multi-node Power Feed Branching Units for Subsea Optical Networks

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Solution Overview

Problem

Subsea optical communication systems face limitations in power delivery due to voltage and current constraints, which restrict the transmission capacity and require excessive power for increasing bandwidth, leading to high costs and complex re-architecting of existing systems.

Innovation Solution

A multi-node network with power feed branching units (PFBUs) that form a DC grid, enabling bi-directional power distribution and a shared power scheme, allowing the trunk path to span longer distances while maintaining nominal power and reducing system costs through redundancy and efficient power regulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If power delivery voltage and current are increased to expand optical bandwidth and transmission capacity, then transmission capacity is improved, but system cost and complexity increase significantly

Engineering Contradiction:
Improvetransmission capacityVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system segments the single-point power delivery architecture into a distributed mesh network of power feed branching units (PFBUs) interconnected through optical fiber. Each PFBU independently manages power for local components, eliminating the need for high voltage/current over long distances while maintaining expanded transmission capacity through the distributed architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Optical fiber serves as an intermediary medium to carry power signals between PFBUs and subsea components. This allows power delivery without requiring high electrical voltage and current through the traditional cable infrastructure, thereby expanding capacity without proportionally increasing system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Area of stationary object

If power delivery distance is extended to span larger bodies of water, then coverage area is improved, but power delivery capability deteriorates due to voltage and current constraints

Engineering Contradiction:
Improvecoverage areaVSAvoidpower delivery capability
Core Design Contradiction:
Area of stationary objectVSPower

Solution Approach 1:

The long-distance power delivery path is segmented into multiple shorter segments, each managed by individual PFBUs. These units are distributed along the cable route and interconnected via optical fiber, allowing each segment to operate within practical voltage and current limits while collectively spanning large bodies of water.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from one-dimensional linear power delivery through the cable to a two-dimensional mesh network topology. PFBUs are positioned at multiple points along the cable and interconnected via optical fiber, creating redundant power paths that enable extended coverage without compromising power delivery capability at any single location.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Power

If existing systems are re-architected to increase power delivery capability, then power delivery capability is improved, but implementation difficulty and cost increase

Engineering Contradiction:
Improvepower delivery capabilityVSAvoidimplementation ease
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

PFBUs are designed as universal, multi-functional units that can be deployed at various locations along the cable route. Each unit performs multiple functions: local power distribution, optical signal processing, and mesh network communication. This modularity simplifies deployment and reduces implementation difficulty compared to customizing entire system architectures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses identical replicated PBU units throughout the network rather than custom-designed components. Each PFBU is a copy of the standardized design, simplifying manufacturing, deployment, and maintenance. This replication strategy increases power delivery capability through数量 rather than through complex individual component design.

Inventive Principle:
Principle #26Copying

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

The solution enables longer subsea optical communication system spans without increasing system voltage and current, reducing costs and complexity, and allows for higher available power for optical amplification while maintaining redundancy and fault tolerance.

Implementation Method 1

a multi-node network with power feed branching units (PFBUs) that form a DC grid, enabling bi-directional power distribution and a shared power scheme

Methodology Applied
Scientific EffectElectrical energy transformation:

Data Source

PatentEP3596834B1Techniques for providing adaptive power distribution using a multi-node network of power feed branching units (PFBUS) and an undersea optical communication system using same
Publication Date: 2022.04.27 SUBCOM LLC
  • EP3596834B1 patent drawingFigure 1
  • EP3596834B1 patent drawingFigure 2
  • EP3596834B1 patent drawingFigure 3

AI summary

In general, a branching configuration used in a wavelength division multiplexed (WDM) optical communication system, consistent with the present disclosure, includes a power feed branching unit (PFBU) (118-3) having a multi-port DC/DC converter (DDCM) arrangement (501/518) capable of a plurality of operating modes to distribute power in a bi- directional manner. The DDCM arrangement (501/518) may include a plurality of ports (626- 1, 626-2, 626-3) for electrically coupling to one or more trunk path cable segments (114-3, 114-4) and for electrically coupling to a branch cable segment (113). A plurality of PFBUs (118-3, 118-4, 118-5, 118-6) may be disposed along a trunk path (112), with each PFBU powering an associated branch path, without each branch path necessarily having local power feed equipment (PFE). In instances where a branch path includes a local PFE (190), an associated PFBU may draw power from the branch path in order to make power available to the trunk path as needed.