Modular Power Converter Branch Units for Subsea Maintenance

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Solution Overview

Problem

High voltage power converters, especially those for offshore applications, are heavy and difficult to transport and maintain, leading to increased costs and downtime due to their large size and complex installation requirements.

Innovation Solution

A modular power converter design where each phase-leg is housed in a separate, sealed enclosure, allowing for individual removal and replacement of branch units, including a redundant unit for backup, facilitating maintenance and reducing downtime through remote control and wet-mateable connectors for subsea operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a power converter is designed as a single integrated unit, then it provides complete power conversion functionality, but it becomes heavy and difficult to transport and maintain

Engineering Contradiction:
Improvepower conversion functionalityVSAvoidtransport and maintenance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The power converter is divided into multiple independent branch units, each capable of functioning separately. Each branch unit is housed in its own sealed enclosure, allowing individual removal and replacement without affecting other branches. This segmentation enables easier transport and maintenance while maintaining complete power conversion functionality through the collective operation of all branches.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If a power converter is designed as a single integrated unit, then it ensures system integrity, but maintenance and repair require complete system shutdown and lengthy transport operations

Engineering Contradiction:
Improvesystem integrityVSAvoiddowntime during maintenance
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

By segmenting the power converter into independent branch units with separate sealed enclosures, the system maintains integrity through standardized connection interfaces while enabling individual branch maintenance. This allows other branches to continue operating during maintenance of a single branch, significantly reducing downtime.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A redundant branch unit is provided in standby configuration, already prepared and tested before failure occurs. When a branch fails, the redundant unit can be quickly connected to replace the failed branch without requiring complex diagnostics or preparation, minimizing downtime.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a power converter is designed as a single integrated unit, then it provides redundant capacity, but the weight and handling difficulty increase significantly

Engineering Contradiction:
Improveredundant capacityVSAvoidhandling weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The redundant branch unit is segmented as a separate, standalone module rather than being integrated into the main converter body. This allows the redundancy to be provided without increasing the weight of individual handling units, as each branch including the redundant one can be handled independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The redundant branch unit is extracted as a separate module that can be stored independently and only installed when needed. This provides the reliability benefit of redundancy without permanently increasing the weight and handling complexity of the operational converter assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of repair

If branch units are housed in separate sealed enclosures, then individual module replacement is enabled, but the overall device complexity increases

Engineering Contradiction:
Improveindividual module replacementVSAvoidenclosure configuration
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

While segmentation into separate enclosures does increase structural complexity, it dramatically simplifies repair operations by enabling individual module replacement. The standardized enclosure design with uniform connection interfaces ensures that the complexity increase is manageable and offset by the significant ease of repair gained.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3238333B1Modular power converter
Publication Date: 2019.05.29 ABB (SCHWEIZ) AG
  • EP3238333B1 patent drawingFigure 1
  • EP3238333B1 patent drawingFigure 2~3
  • EP3238333B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to a power converter (200) comprising a first node (210) adapted to receive a direct current power, a second node (220) adapted to output a three-phase alternating current power, and at least three branch units (230). A branch unit is electrically connectable to the first node and the second node and adapted to convert the received DC into a respective phase of the output three-phase AC. Further, the branch unit is arranged in a sealed enclosure (435) which is separately arranged from sealed enclosures of the other branch units, thereby forming separate branch unit modules (430). The separate branch unit modules may facilitate maintenance and transport of the power converter.