Active Power Determination via Switching Frequency for Quench Detection
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Solution Overview
Problem
Existing methods for detecting quench events in superconducting electrical devices are slow and require additional sensors, making it difficult to rapidly determine efficiency and prevent damage from abrupt transitions to the normal conducting state.
Innovation Solution
A method that determines active power based on the switching frequency of a power converter, allowing for quick quench detection and dynamic efficiency assessment without additional sensors, by measuring voltages and currents, calculating instantaneous powers, and determining the mean active power within a switching period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors (voltmeters, Hall sensors) are used to detect quench events, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The power converter's existing voltage and current measurements are used for multiple purposes: both for controlling the electrical device and for detecting quench events. This eliminates the need for additional dedicated sensors while maintaining accurate quench detection capability.
Solution Approach 2:
The system uses its own operational parameters (voltage and current measurements already taken for control purposes) to detect quench events, rather than requiring separate measurement systems. The electrical device essentially monitors itself through its control system.
2Measurement precision
If conventional active power determination based on fundamental period is used, then measurement precision is improved, but speed of detection deteriorates
Solution Approach 1:
The active power calculation is segmented into smaller time intervals based on the switching period of the power converter rather than using the full fundamental period. This allows multiple power assessments within one fundamental period, significantly improving detection speed while maintaining accuracy through proper averaging.
Solution Approach 2:
Active power is determined periodically at each switching cycle of the power converter, allowing continuous monitoring and rapid detection of quench events. The periodic switching nature of the converter provides natural sampling points for power calculation.
3Device complexity
If quench detection is delayed, then device complexity is reduced, but loss of time increases
Solution Approach 1:
The system continuously calculates instantaneous active power at each switching cycle in advance, so that when a quench occurs, the detection is already immediate. The preliminary continuous monitoring eliminates detection delay while using only the existing control system infrastructure.
Data Source
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AI summary
The present invention relates to a method for determining the active power of an electrical device (3), in particular a superconductive electrical device, on the basis of the switching frequency, and to an apparatus (4) for carrying out the method. The electrical device (3) is a multiphase electrical device and is supplied with a voltage, having a fundamental that has a variable frequency and amplitude and has a fundamental period T, via a power converter (2) connected to an energy source or sink (1) or supplies such a voltage to the power converter (2). The determination of active power on the basis of the switching frequency makes it possible to quickly detect quenching without the use of additional sensors and also makes it possible to dynamically and accurately determine the efficiency of the electrical device (3).