Developing melt-textured YBCO

Habisreuther, T.; Zeisberger, Matthias; Litzkendorf, D.; Surzhenko, O.; Gawalek, W.

doi:10.1007/s11837-000-0143-8

Cited by 4 publications

(2 citation statements)

References 10 publications

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“…In our case a transformer type FCL built up of YBCO rings [2] using a magnetic core with an adjustable air gap is being investigated. The basic design is one with a closed magnetic core.…”

Section: Increasing Power Rating and Reliability Of Thementioning

confidence: 99%

Improvement of Functionality and Reliability by Inductive HTS Fault Current Limiter Units

Györe

Semperger

Farkas

et al. 2005

IEEE Trans. Appl. Supercond.

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The inductive type high temperature superconducting fault current limiter (HTS FCL) is one of the prospective and developing applications of HTS materials. A transformer type FCL build up of YBCO rings using a magnetic core with an adjustable air gap has been built and studied. For the practical applications of HTS FCLs in industrial environments we have investigated various connections of individual FCL units, viz. series, parallel and matrix (combination of series and parallel) arrangements of FCL groups to increase the fault power capacity as well as the reliability of HTS FCLs. A modeling method and a respective simulation have been developed, which include the hysteresis and heating of the HTS and the nonlinear characteristics of the magnetic core. Simulation results were verified by tests. We propose an important application viz. a self-limiting transformer using HTS YBCO rings, which is a combination of a transformer and a fault current limiter in one unit. The theory and the build-up of such a transformer is described, test results with respect to the operation of the self-limiting transformer are presented.Index Terms-Fault current limiter, high-temperature superconductors, inductive-type, superconducting devices. I. INCREASING POWER RATING AND RELIABILITY OF THE FAULT CURRENT LIMITERT HE inductive type high-temperature superconducting (HTS) fault current limiter (FCL) is one of the prospective and developing applications of HTS, which can make electric power networks more reliable [1]. In our case a transformer type FCL built up of YBCO rings [2] using a magnetic core with an adjustable air gap is being investigated. The basic design is one with a closed magnetic core. This design allows fast activation and recovery processes both within 5 ms. We developed and applied a special design to significantly reduce the impedance in normal operation mode, and to properly adjust the impedance in limitation mode. The FCL can be designed with predictable parameters, and can withstand thousands of activation and recovery cycles [3], [4].For practical applications of HTS FCLs in industrial environments we investigated the possibilities to increase power rating and reliability. For the mentioned purposes we investigated various FCL topologies. In our terms topology means the type of connections of individual units. Units can be arranged in series, parallel and combined (matrix) connections. Tests were performed for series and parallel connections of FCLs to investigate the fault processes in the individual units and the resultant effects of the whole FCL group [5]. Fig. 1 shows the interrelations of the two parallel connected FCLs. Increasing the current, it achieves the activation value of FCL#1, its main field impedance appears and it limits the current of its own branch. The current decreases along this branch and, at the same moment, the current of FCL#2 increases. When the current exceeds the activation value of FCL#2, it is also activated. In this state the whole FCL group is in the limitation mode.When decreas...

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“…In our case a transformer type FCL built up of YBCO rings [2] using a magnetic core with an adjustable air gap is being investigated. The basic design is one with a closed magnetic core.…”

Section: Increasing Power Rating and Reliability Of Thementioning

confidence: 99%

Improvement of Functionality and Reliability by Inductive HTS Fault Current Limiter Units

Györe

Semperger

Farkas

et al. 2005

IEEE Trans. Appl. Supercond.

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show abstract

“…At higher currents the HTS goes into the normal state, the FCL is activated and it limits the current. When using YBCO rings, the transition from the superconducting to the normal state is very sharp [4]. At lower currents (below 1 A) the HTS returns into the superconducting state.…”

mentioning

confidence: 99%

Series and parallel connections of inductive high-temperature superconducting fault current limiters

Györe¹,

Farkas²,

Vajda³

2004

Supercond. Sci. Technol.

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High-temperature superconducting (HTS) fault current limiters (FCLs) can make electric power networks more reliable. For an inductive type FCL we have developed and applied a special design to significantly reduce the impedance in normal operation mode, and to properly adjust the impedance in limitation mode. The FCL can be designed with predictable parameters, and can withstand thousands of activation and recovery cycles. For practical application of HTS FCLs in industrial environments we have investigated the possibilities to increase power rating and reliability. For the purposes mentioned we have examined various FCL topologies: series, parallel and matrix arrangements. In this paper we present the results of experimental studies of the mentioned and practically useful FCL topologies. Tests were performed for series and parallel connections of FCLs to investigate the fault processes in the individual units and the resultant effects of the whole FCL group.

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