Partitioned Magnetic Shield for Superconducting Generator
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Solution Overview
Problem
Conventional magnetic shields in superconducting generators are heavy due to ferromagnetic materials, which increases the weight and cost of wind turbines, and traditional designs struggle to minimize eddy current losses while maintaining magnetic field coupling efficiency.
Innovation Solution
A partitioned magnetic shield design comprising a first and second magnetic shield ring with an air gap and a magnetic shield bridge link, which controls the magnetic field and reduces eddy current losses by keeping residual flux within the shield, thereby minimizing weight and electromagnetic losses in the armature support structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional magnetic shield made of ferromagnetic material is used, then magnetic field coupling efficiency is improved, but weight increases significantly
Solution Approach 1:
The magnetic shield is divided into two separate rings (first magnetic shield ring and second magnetic shield ring) with an air gap between them, connected by a magnetic shield bridge link. This segmentation allows the shield to maintain magnetic coupling efficiency while reducing the radial thickness and overall weight of the ferromagnetic material required.
Solution Approach 2:
The patent introduces an air gap dimension between the two magnetic shield rings, creating a three-dimensional structure that controls magnetic flux distribution. This dimensional change allows the magnetic field to be guided more efficiently through the shield structure, maintaining coupling efficiency with reduced material thickness.
2Weight of moving object
If the radial thickness of the magnetic shield is reduced to minimize weight, then weight decreases, but eddy current losses increase
Solution Approach 1:
By segmenting the magnetic shield into two rings with an air gap, the patent creates a structure that limits the path length for eddy currents. The air gap acts as a barrier that interrupts large-scale eddy current loops, reducing energy losses even with reduced radial thickness.
Solution Approach 2:
The air gap serves as an intermediary element between the two magnetic shield rings. It mediates the magnetic flux distribution in a way that maintains shielding effectiveness while the magnetic shield bridge link provides a controlled path for magnetic coupling, indirectly managing eddy current paths.
3Loss of energy
If a laminated structure is used for the magnetic shield to reduce eddy current losses, then eddy current losses decrease, but manufacturing complexity increases
Solution Approach 1:
The magnetic shield is segmented into two rings connected by a bridge link, which can be manufactured as separate components and assembled. This segmentation allows each part to be optimized and manufactured independently, potentially using laminated structures where needed, while simplifying the overall manufacturing process through modular assembly.
Solution Approach 2:
The magnetic shield design allows for flexibility in manufacturing approaches. The two rings and bridge link can be manufactured using different techniques (laminated, solid, or hybrid) depending on specific requirements, allowing optimization of eddy current losses without committing to a single complex manufacturing process for the entire shield.
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 design achieves reduced eddy current losses and lower weight penalties, enhancing the efficiency and power density of superconducting generators while maintaining torque density and magnetic field coupling, leading to lighter and more cost-effective wind turbines.
Implementation Method 1
The superconducting wires generate very high magnetic field, for example, on the order of 7 Tesla or larger due to the high current densities in the field winding
Implementation Method 2
Virtually all of the benefit from the magnetic shield is achieved by allowing the magnetic shield to be heavily saturated
Implementation Method 3
the magnetic shield reduces eddy current losses by keeping residual flux within the shield
Data Source
AI summary
An annular rotating armature is presented. The annular rotating armature includes an armature winding having a plurality of coils, an armature support structure and a magnetic shield disposed between the armature winding and the armature support structure. The magnetic shield having a first magnetic shield ring, a second magnetic shield ring disposed concentric to the first magnetic shield ring and coupled to the first magnetic shield ring via a magnetic shield bridge link. An air gap is formed between the first magnetic shield ring and the second magnetic shield ring. The magnetic shield bridge link is disposed within the air gap. A superconducting generator including the annular rotating armature and a wind turbine having such superconducting generator are also presented.