Experimental studies of the quench behaviour of MgB 2 superconducting wires for fault current limiter applications

Abstract-In recent years, major industrialized countries have began to be concerned about the need for developing strategies on the integration and protection of the growing power capacity of renewable source energies, attracting back their interest on the development and understanding of superconducting fault current limiters (SFCL). The reasons for this are simple: a SFCL may offer a rapid, reliable and effective current limitation, with zero impedance during normal operation, and an automatic recovery after the fault. Nowadays, most of the R&D projects have turned towards to the study of the resistive type SFCL due to their potential to be small, and the likely decrease in price of 2G coated conductors. Thus, in this paper we provide an updated review on the state of the art of resistive type SFCL, emphasizing on the different approaches for the numerical modelling of their local physical properties, as well as on the already tested experimental concepts. Comparison between the properties and characteristics of different resistive-type SFCL using different superconducting materials is presented.

Section: Practical Implementation Of Sfcl: Field Test Status and mentioning

confidence: 99%

Resistive-Type Superconducting Fault Current Limiters: Concepts, Materials, and Numerical Modeling

Ruiz

Zhang

Coombs

2015

“…In all these practical applications, a fundamental role is played by the material sheath and architecture of the conductor since they have to provide suitable mechanical properties for windings, protection against magnetic flux jumps, and an appropriate thermal and electrical stabilization [4]- [6]. These issues lead us to focus on the development of multifilamentary wires or tapes, including a material with low resistivity and high thermal conductivity.…”

Section: Study Of the Superconducting And Thermalmentioning

confidence: 99%

“…Furthermore, if we consider that such superconductor can operate between 20K and 30K, within the range of a commercial cryocooler, and that its raw materials and production costs are much lower than those of the high T c superconductors, then it is easy to think at MgB 2 as a useful conductor for magnets, fault current limiters, motors, generators and transformers [3]. In all these practical applications a fundamental role is played by the material sheath and architecture of the conductor since they have to provide suitable mechanical properties for windings, protection against magnetic flux jumps and an appropriate thermal and electrical stabilization [4,5,6]. These issues lead to focus the conductor development on the multifilamentary wires or tapes including a material with low resistivity and high thermal conductivity.…”

mentioning

confidence: 99%

Study of the Superconducting and Thermal Properties of ex situ GlidCop-Sheathed Practical $\hbox{MgB}_{2}$ Conductors

Malagoli¹,

Tropeano

Cubeda

et al. 2009

In dc and ac practical applications of MgB 2 superconducting wires, an important role is represented by the material sheath that has to provide, among other things, a suitable electrical and thermal stabilization. One way to obtain a large-enough amount of low-resistivity material into the conductor architecture is to use it as the external sheath. In this paper, we study ex situ multifilamentary MgB 2 wires fabricated with oxide-dispersionstrengthened copper (GlidCop) as the external sheath in order to reach a good compromise between critical current density and thermal properties. We prepared three GlidCop samples with different contents of dispersed submicroscopic Al 2 O 3 particles. We characterized the superconducting and thermal properties, and we showed that the good thermal conductivity, together with the good mechanical properties and a reasonable critical current density, makes the GlidCop composite wire a useful conductor for applications where high thermal conductivity is required at temperatures above 30 K, such as superconducting fault-current limiters.

“…ESISTIVE superconducting fault current limiters (SFCL's) offer the advantages of low weight and compact structure. Magnesium Diboride (MgB 2 ) in simple round wire form has shown potential in resistive SFCL's [1][2][3][4][5]. Multistrand MgB 2 wire can be used in SFCL coil design to increase the transport current capacity [4,6].…”

Section: Introductionmentioning

confidence: 99%

Resistive superconducting fault current limiter AC loss measurements and analysis

Pei

Zeng

Smith

et al. 2016

Resistive superconducting fault current limiters (SFCL's) offer the advantages of low weight and compact structure. Multi-strand Magnesium Diboride (MgB 2) wire can be used in SFCL coil design to increase the transport current capacity. A monofilament 0.36 mm MgB 2 wire with a stainless steel sheath was used to build three SFCL coils with 3 strands, 16 (9+7) strands and 50 (28+22) strands of the MgB 2 wire. The quench current level and AC losses in the MgB 2 wire are critical design parameters for a resistive SFCL. The experimental results showed the measured quench current densities reduced as the strand number increased and the AC losses increased as the strand number increased. An axisymmetric 2D finite element (FE) model therefore was built to analyze the current distribution and the AC losses in the coil. The multi-stranded coil FE model showed that proximity effect can modify the current distribution in the strands. This not only reduces the current carrying ability, but also increases the AC losses non-linearly. The FE model confirmed the issues highlighted by the experimental testing. Finally a winding method for multi-strand coil has been proposed to reduce the impact of these effects.