Superconducting Closed Circuit Charging Without Cryogenic Switch Heating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for charging superconducting circuits face inefficiencies and heat transfer issues in cryogenic environments, particularly with the use of superconducting switches that heat localized areas, affecting nearby superconducting elements and requiring significant power, and inductive charging methods that are technically complex and inefficient.

Innovation Solution

A method involving superconducting circuits with branches of different inductances, where the supply current is primarily fed to the branch with lower inductance until its critical current is reached, allowing asymmetric charging without superconducting switches, using direct current feeding and adjusting inductance through geometry and interaction with other elements to achieve efficient charging and discharging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a superconducting switch is used to charge a superconducting circuit, then the circuit can be charged by redirecting current, but significant power is required to heat the switch and the thermal status of the entire cryogenic environment is affected

Engineering Contradiction:
Improvecharging efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent removes the superconducting switch component entirely from the system. Instead of using a switch to redirect current, the invention employs a passive resistive element that naturally directs current flow based on resistance differences, eliminating the need for active heating and switching operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the active thermal control mechanism (heating the superconducting switch) with a passive electrical resistance-based current division mechanism. The resistive element creates an asymmetric current path that automatically directs charging current without requiring thermal intervention.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If a superconducting switch is used to charge a superconducting circuit, then the circuit can be charged, but it is difficult to localize the heating only in a portion of the circuit without changing the thermal status of the entire cryogenic environment

Engineering Contradiction:
Improvelocalization of heatingVSAvoidthermal control complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent removes the superconducting switch component entirely from the system. Instead of using a switch to redirect current, the invention employs a passive resistive element that naturally directs current flow based on resistance differences, eliminating the need for active heating and switching operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a resistive element as an intermediary component between the power supply and the superconducting circuit. This resistive element serves as a mediator that controls current distribution through its resistance properties, replacing the need for complex thermal control of superconducting switches.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If inductive charging is used to avoid heat transfer into the cryogenic system, then heat transfer is avoided, but high technical effort and special non-standard tools are required

Engineering Contradiction:
Improveheat transferVSAvoidtechnical effort
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent replaces the complex inductive charging system with a simple direct current feeding approach. Instead of using external magnets and inductive coupling, the invention uses direct electrical connection through current leads with a resistive element to control current flow, eliminating the need for specialized inductive charging equipment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the approach from indirect inductive energy transfer to direct electrical current feeding. By altering the charging mechanism from electromagnetic induction to direct conduction with resistive control, the system achieves simplicity while maintaining the benefit of avoiding heat transfer into the cryogenic environment.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If the first branch has lower inductance than the second branch, then asymmetric charging is achieved with the supply current primarily feeding the first branch, but the circuit requires asymmetric geometry and inductance adjustment

Engineering Contradiction:
Improvecharging efficiencyVSAvoidinductance matching
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent intentionally introduces asymmetry into the circuit by placing a resistive element in one branch, creating different resistance values between branches. This asymmetric design is deliberate and functional, enabling the resistive element to control current distribution asymmetrically during charging, with the supply current primarily flowing through the branch with lower resistance.

Inventive Principle:
Principle #4Asymmetry

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 low technical effort, high-efficiency charging and discharging of superconducting circuits without heat transfer into cryogenic systems, allowing for compact and powerful magnet designs with reduced critical currents, enhancing magnetic field generation while minimizing thermal impact.

Implementation Method 1

a superconducting sub-circuit with a close superconducting path

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Implementation Method 2

the first inductance L1 of the first branch is lower than the second inductance L2 of the second branch

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4068311B1Method for charging and/or discharging and/or reversing the charge of a superconducting-switch-free superconductively closed circuit via direct current feeding, superconducting-switch-free superconductively closed circuit for use with said method, superconducting magnet and method for producing said superconducting circuit
Publication Date: 2024.02.28 BRUKER SWITZERLAND AG
  • EP4068311B1 patent drawingFigure 1
  • EP4068311B1 patent drawingFigure 2
  • EP4068311B1 patent drawingFigure 3

AI summary

A method for charging a superconducting-switch-free superconductively closed circuit with a sub-circuit comprising an entry connection area (6a) and an exit connection area (6b) dividing the sub-circuit into a first branch (1) with a first inductance L1 and a second branch (2) with a second inductance L2, and currents leads (3), comprising: Choosing the positions of the connection areas (6a, 6b) and/or the geometry of the branches (1, 2) and/or the cross sections of the branches (1, 2) such that the first inductance L1 is lower than the second inductance L2; modifying an initial current 10 (I0≥0) by feeding a supply current Iin into the circuit comprising: (a) Increasing the supply current until a first partial current in one branch reaches the critical current, (b) Further increasing the supply current to Δa resulting in a second partial current in the other branch, (c) Reducing the supply current Iin to 0A, resulting in a remanent circuit current within the circuit.