Experimental Evaluation of AC Losses of a DC Restive SFCL Prototype

Imparato, S. Inserra; Morandi, Antonio; Martini, L.; Bocchi, M.; Grasso, G.; Fabbri, Massimo; Negrini, Francesco; Ribani, Pier Luigi

doi:10.1109/tasc.2010.2043726

Cited by 22 publications

(5 citation statements)

References 13 publications

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“…This implies that if a transport current I is applied, no solution can be found in the case I > I c [6]. This makes the critical state based numerical models inappropriate to deal with some applications of interest such as for example fault current limiters and magnets where a current exceeding the conventional critical value may be forced in the superconductor [20][21][22] (in the case of a magnet this may happen if a local over-temperature occurs thus creating a section with lower I c ). A way to overcome this difficulty is to supplement the critical state model with the transition to the normal state.…”

Section: Critical State Based Modelsmentioning

confidence: 99%

“…We will see in section 6 that by introducing a space discretization of the current density and by using the constraint (23) the voltage can be eliminated from (22) and a state equation involving the transport current as a source term along with the time derivative of the external vector potential can be obtained.…”

Section: Axial Symmetrymentioning

confidence: 99%

“…The 2D cross section of the domain is subdivided into a finite number of elements and an approximate distribution of the current density satisfying equation (22) in the weak form is sought. For this purpose the space and the time dependence of the current density over the domain are separated, i.e.…”

Section: Finite Dimensional Modelmentioning

confidence: 99%

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2D electromagnetic modelling of superconductors

Morandi¹

2012

Supercond. Sci. Technol.

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Some issues concerning the numerical analysis of superconductors are discussed and a novel approach to 2D modelling is proposed. Both axial and translational symmetric as well as current driven and voltage driven systems are examined in detail. The E–J power law is chosen instead of the critical state model as a constitutive relation of the material and the need to modify this relation in order to account for the normal state transition at high currents is discussed. A linear space reconstruction of the current density by means of nodal shape functions is used in order to build the finite dimensional model. A method to relax the tangential continuity of the current density, which is inherent to the discretization method used, is discussed. The performance of the proposed approach, both in terms of current distribution and AC loss, is evaluated with reference to some cases of practical interest involving composite materials. The role of the electric field as a natural state variable for superconducting problems is also pointed out. The use of the method as an alternative to the circuit approach or edge elements for modelling the superconductors is finally discussed.

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Section: Critical State Based Modelsmentioning

confidence: 99%

Section: Axial Symmetrymentioning

confidence: 99%

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2D electromagnetic modelling of superconductors

Morandi¹

2012

Supercond. Sci. Technol.

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“…The Graetz bridge must have a power capacity to accommodate the losses, so the losses are much less when using superconducting inductors. Recently, a bridge type SFCL applied with a thyristor or an insulated gate bipolar transistor (IGBT) switch instead of a diode, and a DC resistance type in which a superconducting coil capable of being quenched is added to the diode bridge has been proposed [14][15][16][17][18][19][20][21][22][23][24][25]. However, this type of SFCL has the disadvantage of being larger than other types of SFCL due to the superconducting coil.…”

Section: Introductionmentioning

confidence: 99%

Fault Current Limiting Characteristics of a Small-Scale Bridge Type SFCL with Single HTSC Element Using Flux-Coupling

Han¹,

Ko²,

Lim³

2020

Electronics

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In this paper, a bridge type superconducting fault current limiter (SFCL) with a single high-temperature superconducting (HTSC) element is proposed to allow fault current limiting operation in direct current (DC) conditions. First, the principle of operation of the bridge type SFCL with a single HTSC element using flux-coupling was presented. After the fault occurrence, the fault current limiting operation and voltage characteristics, the power load characteristics of each device, and the energy consumption of the two coils and the HTSC element were analyzed in the proposed SFCL. As a result, it is confirmed that in the case of the additive polarity winding, the power consumption and the energy consumption of the HTSC element were lower than those in the subtractive polarity winding, and the fault current limiting characteristics were excellent.

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“…It is already reported that the SFCL improves the transient stability of the wind power system [13–15]. However using the SFCL introduces significant system losses during normal operation of the system [16], and reduces the overall system efficiency. To overcome this problem, a novel DC resistive SFCL is reported and explained in detail in [17], which is based on the combined use of the ‘resistive’ and the ‘rectifier’ fault current limiter concepts.…”

Section: Introductionmentioning

confidence: 99%