Quench Detection System Research Articles

Conceptual Design of Quench Detection System for the CS HTS Magnets

Conceptual Design of Quench Detection System for the CS HTS Magnets

A High Voltage Signal Conditioner for the Quench Detection System of the ITER Superconducting Magnet

A High Voltage Signal Conditioner for the Quench Detection System of the ITER Superconducting Magnet

Quench Detection System Consolidation for the HL-LHC Era

Quench Detection System Consolidation for the HL-LHC Era

Design of a Radiation Tolerant Power Supply for the Upgrade of LHC Quench Detection System

Design of a Radiation Tolerant Power Supply for the Upgrade of LHC Quench Detection System

Multi-Sensor Quench Detection System for an HTS Slotted Superconducting Cable

Multi-Sensor Quench Detection System for an HTS Slotted Superconducting Cable

Design of Quench Detection System for Background DC Magnet in the Conductor Performance Research Platform of CRAFT

Design of Quench Detection System for Background DC Magnet in the Conductor Performance Research Platform of CRAFT

Quench detection electronics for FAIR

The SIS100 synchrotron and the Super-FRS fragment separator are the core machines of the Facility for Antiproton and Ion Research (FAIR), currently under construction in Darmstadt, Germany. A uniform quench detection system will ensure monitoring of superconducting magnets of both SIS100 and Super-FRS. Further, Plasma Physics and Applications (APPA) experiments will also make use of it.The distributed quench detection system of FAIR is based on hundreds of quench detection units. Their design, testing experience and first operational results are presented in this work.

Mutual Induction Caused by IVCC Currents on Quench Detection Circuits of the KSTAR TF Coils

The Quench Detection System (QDS) for the Toroidal Field (TF) coils and the Poloidal Field (PF) coils made of Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn or NbTi cable-in-conduit conductors is using Wheatstone bridges to compensate induced voltages, which are generated by electrical currents of the superconducting coils and a plasma, on the quench detection circuits of the Korea Superconducting Tokamak Advanced Research (KSTAR) device. On the other hand, the KSTAR device is equipped with In-Vessel Control Coils (IVCCs), which consist of 16 segmented windings made of normal conductors, for fast plasma position control, field error correction, and resistive wall mode stabilization. Electrical currents of the middle Field Error correction Coil (FEC) in a part of the IVCCs have strong mutual induction on the quench detection circuits of the TF coils due to the paths of the FEC's conductors, and the middle FEC currents, which had unusually long and very steep ramps, raised an emergency protection sequence of the TF coils in a KSTAR plasma experiment. Quench detection circuits only using traditional Wheatstone bridges are insufficient to cancel out such a mutual induction; whereas, the mutual induction can be numerically compensated in a theoretically straightforward calculation.

Anomaly detection at the European X-ray Free Electron Laser using a parity-space-based method

A novel approach to detect anomalies in superconducting radio-frequency (rf) cavities is presented, based on the parity space method with the goal to detect quenches and distinguish them from other anomalies. The model-based parity space method relies on analytical redundancy and generates a residual signal computed from measurable rf waveforms. The residual is a sensitive indicator of deviation from the model and provides different signatures for different types of anomalies. This new method not only helps with detecting faults but also provides a catalog of unique signatures, based on the detected fault. The method was experimentally verified at the European X-ray Free Electron Laser (EuXFEL). Various types of anomalies incorrectly detected as quenches by the current quench detection system are analyzed using this new approach.9 MoreReceived 28 February 2022Accepted 5 December 2022DOI:https://doi.org/10.1103/PhysRevAccelBeams.26.012801Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasMethods in electromagnetismRadio frequency calculationsAccelerators & Beams

Time–Frequency-Based Quench Detection for HTS VIPER Cable Using Torsional Acoustic Wave

A new quench detection and diagnostic system is required for the reliable operation of high-field superconducting magnets for fusion which is fabricated with high-temperature superconductor (HTS) cables. The conventional voltage-based diagnostic methods have a limitation in detecting local temperature changes in large-scale HTS magnets. To address the limitation, an acoustic-based diagnostic method using torsional waves applied by piezoelectric transducers is proposed. In addition, from the sensor data collected by the piezoelectric transducers, a new monitoring index that can measure the temperature change is extracted via chirplet transform (CT), which is one of the time–frequency analyses. The proposed quench detection method using torsional wave guiding is implemented in a vacuum pressure-impregnated, insulated, partial dislocation, extruded, and roll-formed (VIPER) cable, and the performance of the new index, time–frequency-based phase delay, is validated. This work proves that the propagation characteristics of torsional acoustic waves depend on the strength and location of the heat and that the change can be monitored via the proposed time–frequency-based phase delay. The preliminary development and results of a new quench detection method are discussed to validate future use in complex environments such as fusion power plants.

A Quench Detection and Monitoring System for Superconducting Magnets at Fermilab

A quench detection system was developed for protecting and monitoring the superconducting (SC) solenoids for the Muon-to-Electron Conversion Experiment (Mu2e) at Fermilab. The quench system was designed for a high level of dependability and long-term continuous operation. It is based on three tiers: Tier-1, FPGA-based Digital Quench Detection (DQD); Tier-2, Analog Quench Detection (AQD); and Tier-3, the quench controls and data management system. The Tier-1 and Tier-2 systems are completely independent and fully redundant. The Tier-3 system is based on National Instruments (NI) cRIO and provides the user interface for quench controls and data management. It is independent from Tiers 1 & 2. The DQD provides both quench detection and quench characterization (monitoring) capability. Both DQD and AQD have built-in high voltage isolation and user programmable gains and attenuations. The DQD and AQD also includes user configured current dependent thresholding and validation times. A 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> article of the three-tier system was fully implemented on the new Fermilab magnet test stand for the HL-LHC Accelerator Upgrade Project (AUP). It successfully provided quench protection and monitoring (QPM) for a cold superconducting bus test in November 2020. The Mu2e quench detection design has since been implemented for production testing of the AUP magnets. A detailed description of the system along with results from the AUP superconducting bus test will be presented.

Application of the Universal Quench Detection System to the Protection of the High-Luminosity LHC Magnets at CERN

The Universal Quench Detection System (UQDS) has been primarily developed to detect quenches in various superconducting magnets of LHC’s High Luminosity upgrade (HL-LHC). The functionality of the system, which comprises insulated high-resolution digitizing front-end channels and a central processing element, is mainly defined by the configuration of the central FPGA (Field Programmable Gate Array). Additional elements such as redundant power supplies, configurable interlocking capabilities and a communications controller are completing the functionality of the system. The system’s architecture is designed to be flexible enough to detect quenches in all superconducting elements of HL-LHC. The application-specific digital signal processing and quench detection algorithms are implemented in the firmware of the FPGA and thus can be changed according to the required specifications. To facilitate this process, the firmware has been structured accordingly and automated code generation techniques are used. The strategy of testing prototypes of the quench detection system with prototypes of the magnets allows an early evaluation of the system, minimizing operational issues in the final installation. This strategy has been already applied at CERN to the 11 T dipole magnets in previous years and extended as well to other magnet families of the HL-LHC Project. We give a system description and focus on the specific configurations for three different magnet families. Prototypes of these magnets have been recently tested at CERN. For each of these, specific features and detection methods have been developed, implemented and evaluated during the magnet tests.

Primary Quench Detection Analysis for DTT Central Solenoid and Poloidal Field Coils

The Central Solenoid (CS) and the Poloidal Field (PF) coils of the DTT tokamak (Divertor Tokamak Test facility, currently being built in the site of ENEA C.R. Frascati &#x2013; Italy) are operated in dynamic mode and, even in normal operation, the self and mutual voltages induced across each coil are of the order of magnitude of &approx;100 V. In DTT, these coils will be realized with superconducting materials and, as a consequence, a reliable and fast quench detection system is required in order to protect the magnets. Being the quench signals 4 orders of magnitude smaller than the operating voltages, the cowound (CW) technology must be adopted for the quench sensors, the only degree of freedom being among a wiring configuration merely aligned with the coil winding (CWA) or aligned and twisted to the coil winding (CWA&amp;TW). In this study, a model of the DTT poloidal magnetic system has been developed up to the details of the single windings (layer or pancake) of the various coils. CWA sensors have also been implemented in the model. Signals coming from the magnetic system and the CWA sensors during the Single Null plasma event have been simulated and compared. The analysis has been carried out up to the level of the elementary winding of each coil, using a lumped parameters circuital model. Finally, a simple theory has been developed aimed at the estimations of the improvements coming from the CWA&amp;TW architecture.

Numerical Model Development for CFETR CSMC Quench Detection System

The Center Solenoid Model Coil (CSMC) is a pre-research project of CFETR, and its task is to design and manufacture the CS superconducting model coil to gain wider experience in solving the related technical problems existing in design and construction of CFETR CS coils. The expected achievement is to charge the CSMC up to the operation current of 47.65 kA and the maximum magnetic field to 12 T with a swift rump rate of 1.5 T/s without quench. Quench detection by voltage measurements is likely to be the fastest available technical solution to avoid coil's damage caused by quench, but the voltage detection is a real challenge due to large noise induced by the power supply in alternating current operation. The pick-up sensors, comprising the co-wound wire (CWW) and the co-wound tape (CWT), are used in the CSMC quench detection system for noise compensation and suppression. To accurately compensate all related induced voltage in the multi-pulse coil system, the foremost task is to estimate the static inductance matrix between the CSMC and its pick-up sensors. In this paper, a numerical model is developed for inductance calculation and analysis. Moreover, several numerical simulations with this design model to evaluate the maximum inductive noises and quench detection signals by CWW and CWT have been conducted for the case of the worst test scenarios.

Formation of Hot Spots in Coated Conductors During Static and Dynamic DC Loading

High voltage DC transport at long distances represents an opportunity for wider use of superconductors. In particular, the second generation of high temperature superconductor tapes produced in form of coated conductors (CC) offers a unique solution for protecting a high-capacity connection against fault currents. In the resistive superconducting fault current limiter (R-SFCL), the CC tape would emerge as a substantial resistance in case of overcoming its critical current, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_c</i> . Non-uniformity of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_c</i> along the CC length is a common issue requiring attention. Because of highly nonlinear current/voltage dependence, the spot with critical current <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_cmin</i> < <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_c</i> could transform into the hot spot with rapid rise of local temperature. Due to its small dimension, it would not create an observable voltage at the device terminals, thus may escape attention of a quench detection system. We have investigated the mechanism of hot spot creation at the DC currents between <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_cmin</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_c</i> , and the analytical formulas have been derived predicting the limits of stable operation. Now we extend the analysis to the case of the limitation event, when for a fraction of second the current exceeds also the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I_c</i> . It is desirable that the temperature rise happens along all the conductor length, leading to a quick reduction of transported DC. Numerical modelling has been utilized to analyze such an event, and a simplified analytical model has been developed to predict the range of currents causing the formation of hot spots.

Processing of the Quench Detection Signals for CS Model Coil of CFETR

The Center Solenoid Model Coil (CSMC) is a pre-research project of CFETR, and its task is to design and manufacture the CS superconducting model coil to gain wider experience in solving the related technical problems existing in design and construction of CFETR CS coils. The expected achievement is to charge the CSMC up to the operation current of 47.65 kA and the maximum magnetic field to 12 T with a swift rump rate of 1.5 T&#x002F;s without quench. Although adequate operational margins have been taken into in the design to avoid the quenches, such events cannot be completely excluded in the life of the CSMC. In order to prevent quench from damaging the CSMC, the quench detection by voltage measurements plays an important role in the protection of the CSMC during commissioning and operation scenarios. To improve the accuracy and reliability of CSMC quench detection, an all-digital quench detection system based on FPGA has been designed for the processing of quench detection signals. This paper describes the design of the quench detection signal processing system, including the composition of quench detection units, the auxiliary compensation for further denoising, the discriminant of quench, and the safety interlock system.

Development of a Quench Detection System for the FAIR Superconducting Devices

Development of a Quench Detection System for the FAIR Superconducting Devices

Quench detection method for superconducting magnets with a phase difference measurement system based on multiple-correlation

Quench detection for superconducting magnets is an ongoing and key issue in magnet design. Quench detection systems must be able to detect quenching rapidly in any area of a certain magnet so that the stored energy of the magnet can be safely discharged. Resistance voltage detection signals are easily submerged in high induced voltages. This paper presents a quench detection method for superconducting magnets with a phase difference measurement system based on multiple correlations to monitor impedance changes from the superconducting state to the normal state during the quench propagation process. The principle behind the proposed method is analysed and a quench detection scheme for superconducting testing coil is designed on the basis of this principle. The multiple-correlation method can suppress all types of coupled voltages to improve the sensitivity and interference resistance of the quench detection system. Experimental results indicate that the proposed method is capable of identifying any type of quenching in a timely and accurate manner. Thus, this method can be used as a backup scheme for quench detection in the Experimental Advanced Superconducting Tokamak.

The Quench Detection System Based on Programmable FPGA and Its Application at IMP

The High Intensity heavy ion Accelerator Facility (HIAF) and Low Energy heavy ion Accelerator Facility (LEAF) of IMP are under construction. They will comprise many superconducting devices and components, such as magnets and current leads, with the superconducting materials covering NbTi, Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn and HTS. On the other hand, most of the superconducting devices have a high energy density and complex structure, requiring a targeted and active protection. In previous quench protection systems implemented at IMP, the quench detection was implemented in software or as microcontroller-based equipment, where power supplies in superconducting circuit provided quench detection functionality as well. These systems have some disadvantages, such as limited functionalities, poor reliability and high susceptibility to interference. Therefore, a new type of quench detection system (QDS) based on programmable FPGA and Isolated analogue input front-ends was developed to overcome these challenges. It is important to note that in the test facilities, there is no ionizing radiation, the QDS does not require radiation tolerance, thus a commercial programmable FPGA product was chosen as the development platform. The QDS is currently being put into operation, and some good results have been obtained in the cold tests of MCBRDP2 (belongs to HL-LHC, NbTi magnet) and FECR (belongs to LEAF, Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn magnet). Based on these successful applications, the new QDS has proven its functionality. The recorded data and practical experience also provided relevant information for the detection algorithms and functional upgrades.

Preliminary studies for the conceptual design of the quench detection system for the DTT TF superconducting magnets

Abstract The superconducting DTT magnetic system needs a quench detection systems (QDSs) fast enough to trigger the dumping of the magnetic energy in case of quench and avoid irreversible damage of the cable systems. With this aim, a primary system based on the detection of the resistive voltage associated with the quench offers the best quench detection guarantees. The tokamak environment is affected by several electromagnetic noises during plasma scenarios so that the resistive voltage detection, during normal operation, can be compromised by the presence of large voltages induced by self and mutual magnetic coupling among coils and with plasma or passive elements: the resulting inductive voltages across a TF coil, or part thereof, could be much higher than the quench voltage thresholds. Voltage compensations techniques, therefore, have necessarily to be foreseen in the QDSs conceptual design, to discriminate the resistive component associated with the quench. We present a reconnaissance of all known electromagnetic noises that could affect a TF coils QDS in DTT: this analysis is conducted by means of analytical calculations, made up with the aim to evaluate and have a prevision of the maximum extent of the voltages induced across TF coils and Double Pancakes (DPs) during, in particular, the Single Null (SN) scenario.