Superconducting Current Limiter Vacuum-Integrated Switch
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Solution Overview
Problem
Existing superconducting fault current limiters face performance compromises due to external control systems and ambient environment limitations, which affect switching speed and thermal integrity, leading to inefficiencies in current limiting and network protection.
Innovation Solution
A current limiter design featuring a superconductor element within a cooling chamber, integrated with a switching arrangement including an actuator, sensor, and controller housed in a vacuum chamber, allowing for rapid and controlled switching based on current density thresholds, enhancing switching speed and thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the switch is designed for ambient environments with external control systems, then the control system can be simplified and placed outside the vacuum chamber, but the switching speed is reduced and thermal integrity is compromised
Solution Approach 1:
The patent merges the switch, actuator, sensor, and controller into a single integrated switching arrangement housed within the vacuum chamber. This consolidation eliminates the need for external control systems and ambient environment switches, thereby achieving rapid switching speeds while maintaining thermal integrity through unified environmental control.
Solution Approach 2:
The patent places the switching arrangement within a vacuum chamber, creating an inert environment that protects the switch and actuator from ambient conditions. This inert atmosphere enables faster switching operations and maintains thermal integrity by isolating the components from external thermal influences.
2Reliability
If the switch operates as fast as possible to limit superconducting heating effects, then fault current limiting is improved, but the switch performance and network protection benefits are compromised
Solution Approach 1:
The patent incorporates a sensor within the switching arrangement that monitors current density in the superconductor element and provides feedback to the controller. This feedback mechanism enables the controller to activate the actuator at precisely the right moment when current density reaches critical levels, achieving rapid fault current limiting while maintaining optimal network protection capabilities through controlled switching timing.
Solution Approach 2:
The patent positions the switch in a pre-charged state within the vacuum chamber, ready for immediate activation. The controller monitors conditions and triggers the actuator to open the switch at the optimal moment before excessive heating occurs, enabling both rapid fault current limiting and sustained network protection benefits.
3Loss of time
If the superconductor element is exposed to prolonged fault current, then fault diagnosis time is extended, but the superconductor element is heated excessively
Solution Approach 1:
The patent implements a dynamic switching arrangement where the switch can be rapidly activated to divert fault current. The controller dynamically monitors current density and triggers the actuator to open the switch at the precise moment when thermal limits are approached, enabling extended fault diagnosis time while preventing excessive superconductor heating through timely current diversion.
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 design improves switching speed, reduces operational delays, and enhances thermal integrity, enabling efficient and self-contained fault current limiting with reduced cooling burdens and improved installation and maintenance, while allowing for various operating regimes and fault discrimination.
Implementation Method 1
The superconductor element has a critical temperature below which the superconductor element is superconducting. Above the critical temperature, the superconductor element becomes a semiconductor. In addition to the critical temperature, the superconductor element has a critical current density. The critical current density is the density of current within the superconductor above which the superconductor element will no longer be superconducting.
Implementation Method 2
the superconductor element is cooled below a temperature at which it becomes superconducting for the rated current of the circuit
Implementation Method 3
the cooling chamber and the switching arrangement are disposed within a vacuum chamber
Data Source
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Figure 2
AI summary
This invention relates to a current limiter comprising a first circuit portion arranged in parallel with a second circuit portion, the first circuit portion comprising a superconductor element arranged in series with a switching arrangement, the second circuit portion comprising a load element, the superconductor element being disposed within a cooling chamber, and the cooling chamber and the switch being disposed within a vacuum chamber, wherein the switching arrangement comprises: a mechanical actuator which is operable between a closed condition in which current is conducted through the first circuit portion and an open condition in which current is diverted from the first circuit portion through the second circuit portion and a controller for monitoring and operating the switch.