T-A Formulation for the Design and AC Loss Calculation of a Superconducting Generator for a 10 MW Wind Turbine

Vargas-Llanos, Carlos Roberto; Lengsfeld, Sebastian; Grilli, Francesco

doi:10.1109/access.2020.3038058

Cited by 37 publications

(28 citation statements)

References 32 publications

(44 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the H-formulation has been employed in the superconducting parts, and the A-formulation has been used in the outer iron stator poles. A T-A formulation-based 2D numerical model for simulating a large-scale superconducting stack/coil has been exploited in [86,90,[97][98][99][100]. The T-formulation has been used to calculate the current density in superconductors, and the A-formulation has been employed to obtain the magnetic flux density in the whole space.…”

Section: Modelling Methodsmentioning

confidence: 99%

“…Due to the thin-film approximation adopted in the T-A formulation, the T-A formulation has been proven to be more efficient and time saving than the H-A formulation. The T-A formulation has recently been applied to the design of a 10-MW HTS wind turbine generator in [100], and the model building methodology combining the resistive model and the superconducting model has been introduced. The modelling results of an example machine regarding the magnetic field and current density distributions are shown in Figure 5 [101].…”

Section: Modelling Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Alternating Current Loss of Superconductors Applied to Superconducting Electrical Machines

Zhang¹,

Wen²,

Grilli

et al. 2021

Energies

Self Cite

View full text Add to dashboard Cite

Superconductor technology has recently attracted increasing attention in power-generation- and electrical-propulsion-related domains, as it provides a solution to the limited power density seen by the core component, electrical machines. Superconducting machines, characterized by both high power density and high efficiency, can effectively reduce the size and mass compared to conventional machine designs. This opens the way to large-scale purely electrical applications, e.g., all-electrical aircrafts. The alternating current (AC) loss of superconductors caused by time-varying transport currents or magnetic fields (or both) has impaired the efficiency and reliability of superconducting machines, bringing severe challenges to the cryogenic systems, too. Although much research has been conducted in terms of the qualitative and quantitative analysis of AC loss and its reduction methods, AC loss remains a crucial problem for the design of highly efficient superconducting machines, especially for those operating at high speeds for future aviation. Given that a critical review on the research advancement regarding the AC loss of superconductors has not been reported during the last dozen years, especially combined with electrical machines, this paper aims to clarify its research status and provide a useful reference for researchers working on superconducting machines. The adopted superconducting materials, analytical formulae, modelling methods, measurement approaches, as well as reduction techniques for AC loss of low-temperature superconductors (LTSs) and high-temperature superconductors (HTSs) in both low- and high-frequency fields have been systematically analyzed and summarized. Based on the authors’ previous research on the AC loss characteristics of HTS coated conductors (CCs), stacks, and coils at high frequencies, the challenges for the existing AC loss quantification methods have been elucidated, and multiple suggestions with respect to the AC loss reduction in superconducting machines have been put forward. This article systematically reviews the qualitative and quantitative analysis methods of AC loss as well as its reduction techniques in superconductors applied to electrical machines for the first time. It is believed to help deepen the understanding of AC loss and deliver a helpful guideline for the future development of superconducting machines and applied superconductivity.

show abstract

Section: Modelling Methodsmentioning

confidence: 99%

Section: Modelling Methodsmentioning

confidence: 99%

Alternating Current Loss of Superconductors Applied to Superconducting Electrical Machines

Zhang¹,

Wen²,

Grilli

et al. 2021

Energies

Self Cite

View full text Add to dashboard Cite

show abstract

“…The T-A formulation of Maxwell's equations is used here to estimate losses in the superconducting tapes by following the approach described in [16]. This means that the induced stator currents are estimated with a star connected load in the building model process.…”

Section: A Modelling Techniquementioning

confidence: 99%

“…In this publication, we estimate losses in the stator's superconducting coils of a synchronous machine for a wind power application. Therefore, we follow the approach described in [16] to model the electrical machine by using the T-A formulation in a finite-element model. The basic design and a brief description of the modelling technique are presented in section II.…”

Section: Introductionmentioning

confidence: 99%

Influence of Coil Position on AC Losses of Stator Superconducting Windings of a Synchronous Machine for a 10 MW Wind Turbine

Vargas-Llanos

Lengsfeld

Noë

et al. 2021

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

One of the main tasks during the design of a superconducting electrical machine is the estimation of losses in the superconducting coils. These losses can be decisive in such applications since they influence the cooling power requirements and the overall efficiency of the machine. In this publication, we focus on the dissipation in the stator superconducting coils of a synchronous machine for a wind turbine application. The T-A formulation of Maxwell's equations is used in a 2D finite element model to analyse the behaviour of the magnetic field around the coils and calculate losses. Particular attention is given to the position of the coils inside a slot and several coil configurations are presented. It is shown that certain coil arrangements lead to a significantly lower total loss, a more uniform loss distribution, which ultimately leads to the possibility of increasing the operating temperature.

show abstract

“…Permanent magnets were used in the rotor to generate the rotating magnetic field. In [12], an AC loss model for one pole pair of a 10 MW generator was built based on T-A formulation. In [13], the T-A formulation was utilised for simulating the electromagnetic behaviour of the whole armature winding of a four-pole all-HTS generator.…”

Section: Introductionmentioning

confidence: 99%

Simulation of AC Loss in the Armature Windings of a 100 kW All-HTS Motor With Various (RE)BCO Conductor Considerations

et al. 2021

View full text Add to dashboard Cite

Superconducting machine designs have historically focused on an isolated, cryogenic rotor and conventional (copper) stator due to unacceptable levels of AC loss in a superconducting stator. Thus, AC loss reduction in the armature windings is one of the key issues for achieving practical all-superconducting motors that could deliver an unprecedented power density and significantly reduce machine complexity. In this paper, a 100 kW, 1500 rpm, all -HTS motor operating at 65 K is designed and AC loss simulations in HTS armature windings wound with different types of (RE)BCO conductor arrangements are carried out by implementing the T-A formulation and a rotating mesh using commercial FEM software COMSOL Multiphysics. Either 4 mm-wide (RE)BCO conductors, 14/2 (14 strands, each strand is 2 mm wide) (RE)BCO Roebel cables, or striated (RE)BCO conductors with four 1 mm-wide filaments are considered in the armature windings. The simulation results show that armature windings wound with Roebel cables or striated conductors can significantly reduce the AC loss in the armature windings compared to windings wound with 4 mm-wide conductors. It is also shown that the AC loss in the armature winding wound with the 4 mmwide (RE)BCO conductors decreases with decreasing operating temperature. The AC loss reduction can be attributed to the reduced magnetic field penetration associated with the increased Ic in the winding. Finally, a 2% AC loss reduction can be achieved in the armature winding wound with (RE)BCO conductors with asymmetric Ic (B, θ) characteristics by simply flipping the direction of the conductors of the armature winding. The simulation results in this work have practical implications for designing all-HTS superconducting rotating machines. Such machines could be suitable for H2 powered electric vehicles like large interstate trucks, heavy machinery, or locomotives.INDEX TERMS FEM (finite element method), T-A formulation, high-temperature superconductors, allsuperconducting motor, armature windings, AC loss, Roebel cables, striated conductors, asymmetric magnetic-field and field-angle dependent critical current

show abstract

T-A Formulation for the Design and AC Loss Calculation of a Superconducting Generator for a 10 MW Wind Turbine

Cited by 37 publications

References 32 publications

Alternating Current Loss of Superconductors Applied to Superconducting Electrical Machines

Alternating Current Loss of Superconductors Applied to Superconducting Electrical Machines

Influence of Coil Position on AC Losses of Stator Superconducting Windings of a Synchronous Machine for a 10 MW Wind Turbine

Simulation of AC Loss in the Armature Windings of a 100 kW All-HTS Motor With Various (RE)BCO Conductor Considerations

Contact Info

Product

Resources

About