Distributed Subsea Transformers for Liftable High-Power Collection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing subsea power collection systems face challenges in upscaling beyond a power rating of 200 MVA, due to weight and size limitations, as well as the need for specialized cooling arrangements and increased costs associated with larger physical volumes.
Innovation Solution
The proposed solution involves a subsea power collection system with a distributed transformer arrangement, utilizing three one-phase subsea transformers in separate housings, each designed to be liftable and with a power rating that does not require specialized cooling, allowing for a higher output power rating of up to 900 MVA.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single three-phase subsea transformer is used to achieve high power rating, then the power output increases, but the weight and size exceed liftable limits and require specialized cooling
Solution Approach 1:
The patent divides a single three-phase transformer into three separate one-phase transformers, each housed individually on the seabed. This segmentation reduces the weight and size of each individual unit to within liftable limits (approximately 300 t per unit) while maintaining the combined power rating capability of up to 900 MVA for the entire power collection system.
2Power
If a single three-phase subsea transformer is used to achieve high power rating, then the power output increases, but specialized cooling arrangements are required
Solution Approach 1:
By segmenting the transformer into three smaller one-phase units, each unit has a reduced power rating that does not require specialized cooling arrangements. The smaller surface-volume ratio of each individual transformer enables efficient natural cooling, eliminating the need for complex forced cooling systems while maintaining the overall high power capability of the distributed arrangement.
3Power
If the physical volume of subsea units is increased to accommodate higher power ratings, then the power output increases, but the cost increases significantly
Solution Approach 1:
The patent employs three separate one-phase transformers instead of a single large three-phase transformer, thereby avoiding the exponential cost increase associated with building a monolithic high-power unit. Each smaller transformer can be manufactured using conventional subsea technology and standard procedures, significantly reducing the capital expenditure while achieving the same combined power rating of up to 900 MVA.
4Power
If a single large subsea transformer is used, then the power rating increases, but maintenance and repairs become more difficult
Solution Approach 1:
By dividing the transformer system into three independent one-phase units, the patent enables individual maintenance and repair of each housing without requiring intervention on the entire system. Each housing can be independently lifted to the surface for topside works, significantly improving maintenance accessibility and reducing system downtime compared to a single large transformer where any repair would require complete system shutdown and complex subsea operations.
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 approach enables the subsea power collection system to achieve higher power ratings while maintaining a simpler constitution and lower lifecycle costs, with all units remaining liftable for maintenance and repairs, thus overcoming the limitations of existing systems.
Implementation Method 1
the power substation comprises three one-phase transformers, wherein each phase of the power output point is connected to a primary side of a corresponding one of the one-phase transformers
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A power collection system (100) for collecting power from a plurality of offshore power generation units comprises a three-phase subgrid (120) and a subsea power substation (130). The subgrid has a plurality of power input points (121) towards the power generation units and a shared three-phase power output point (122). The power substation (130) is connected to the power output point, and its secondary side (132) is arranged to be connected to a power consumer (170). The power substation shall comprise three one-phase transformers (140), which are contained in respective housings (143), wherein each housing is arranged to rest on the seabed and to be liftable to the sea surface separately from the other housings. Each phase of the power output point is connected to a primary side (141) of a corresponding one of the one-phase transformers.