HTS Magnet Coil Quench Protection Using Frequency Loss Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing quench protection systems for high temperature superconducting (HTS) magnets are inadequate in rapidly distributing thermal energy and effectively managing quench conditions, particularly in Rare Earth Barium Copper Oxide (REBCO) superconductors.
Innovation Solution
A Frequency Loss Induced Quench (FLIQ) protection system that uses a current imbalance source to induce a high frequency change in the magnetic field of HTS magnet coils, resulting in inductive heating and effective quench control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If embedded heaters are used to warm the superconductor, then thermal energy is distributed throughout the magnet, but the heating speed and energy distribution efficiency are insufficient for HTS magnets
Solution Approach 1:
The patent replaces the mechanical/thermal system of embedded heaters with an electromagnetic system. AC current is applied to the HTS coil to generate alternating magnetic fields that induce eddy currents within the coil windings, converting electromagnetic energy directly into thermal energy throughout the coil volume, achieving rapid and uniform heating without physical heater elements.
Solution Approach 2:
The patent employs periodic AC current application at specific frequencies to the HTS coil. The alternating current creates time-varying magnetic fields that continuously induce eddy currents, providing sustained periodic heating action that rapidly distributes thermal energy throughout the coil during quench conditions.
2Temperature
If CLIQ method is used to distribute magnetic energy, then current imbalance is created between sections, but the method is not effective in rapidly distributing large amounts of thermal energy in HTS magnets
Solution Approach 1:
The patent replaces the current-based CLIQ method with a direct electromagnetic heating approach. Instead of relying on current imbalance between sections, AC current is applied to generate alternating magnetic fields that directly induce eddy currents and thermal energy throughout the entire coil volume, achieving much faster energy distribution suitable for HTS time constants.
Solution Approach 2:
The patent changes the fundamental parameter from DC current imbalance (CLIQ) to AC magnetic field frequency. By operating at specific AC frequencies, the system optimizes eddy current induction and thermal energy distribution rate, matching the faster thermal response requirements of HTS materials compared to LTS.
3Use of energy by moving object
If capacitance is increased to increase available energy in CLIQ system, then energy availability increases, but the frequency slows down
Solution Approach 1:
The patent replaces the capacitor-based energy storage system with direct AC power application. Energy is supplied continuously through the AC power source rather than being stored in capacitors, eliminating the inverse relationship between energy availability and frequency that constrains CLIQ systems.
Solution Approach 2:
The patent uses periodic AC power application where the frequency and duration can be independently optimized. The AC system provides continuous energy supply at controlled frequencies without requiring large capacitance values, allowing high frequency operation while maintaining sufficient energy delivery for effective quench protection.
4Use of energy by moving object
If voltage is increased to increase available energy in CLIQ system, then energy availability increases, but safety concerns arise
Solution Approach 1:
The patent replaces the high-voltage capacitor discharge mechanism with a controlled AC power system. Energy is delivered through current-controlled AC cycles rather than voltage spikes, reducing insulation stress and safety hazards while providing sufficient energy for quench protection through sustained electromagnetic induction.
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 FLIQ system quickly and uniformly distributes heat energy throughout the HTS magnet coils, effectively minimizing peak hot-spot temperatures and preventing damage during quench conditions.
Implementation Method 1
A Frequency Loss Induced Quench (FLIQ) protection system that uses a current imbalance source to induce a high frequency change in the magnetic field of HTS magnet coils, resulting in inductive heating
Implementation Method 2
induce a high frequency change in the magnetic field of HTS magnet coils, resulting in inductive heating and effective quench control
Implementation Method 3
by driving an imbalance in the transport current between two or more sections of the magnet... the resulting resistance may be distributed throughout the superconducting device
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A protection system capable of safely quenching a high temperature superconductor (HTS) magnet coil. The protection circuit provides for a frequency loss induced quench design that advances the protection technology for HTS magnet coils and provides a protection system that is capable of quickly distributing the heat energy uniformly in all the coil sections when a localized hot-spot is created.