coupled electromagnetic-thermal model of a superconducting … · 2019. 12. 23. · superconducting...

Coupled Electromagnetic-Thermal Model of a Superconducting Motor

Coupled Electromagnetic-Thermal Model of aSuperconducting Motor

Lukasz Tomkow1,a

Vicente Climente-Alarcon1, Anis Smara1, Bartek A.Glowacki1,2,3

1Applied Superconductivity and Cryoscience Group, Department of MaterialsScience and Metallurgy, University of Cambridge, Cambridge, CB3 0FS,

United Kingdom2Institute of Power Engineering, Warsaw 02-981, Poland

3 Epoch Wires Ltd. Cambridge CB22 6SA, UKae-mail: [email protected]

COMSOL Conference 2019Cambridge


Contents

1 Introduction

2 Methods

3 Results

4 Conclusions


Introduction

Contents

1 Introduction

2 Methods

3 Results

4 Conclusions


Introduction

Background

Construction of a fully superconductingmotorRotor with magnetised stacks of HTS tapeCooling with hydrogen to 20KDemagnetisation issues and need formagnetic shieldingAnisotropic heat transfer properties


Introduction

Introduction

GoalsDesign of efficient stacks to serve as trapped field magnets in therotorFind the maximum magnetic flux that can be trappedTackle the issue of demagnetisation to prolong the operation time ofthe motorOptimise heat removal to maintain temperature below critical

MethodsCoupled thermo-electromagnetic modelApplication of A-formulation and H-formulation in a single model todecrease time of computationsConsideration of material parameters


Methods

Contents

1 Introduction

2 Methods

3 Results

4 Conclusions


Methods

Geometry of the model


Methods

Mesh


Methods

Numerical method

H-formulation∂Hx∂t +

∂Hy∂t +

∂∂x (Ez(Jz))−

∂∂y (Ez(Jz)) = 0

Electric field

Ez =

{E0(|Jz |−Jc

Jc

)nJz|Jz | when |Jz | ≥ Jc

0 when |Jz | < Jc

Current density

Jz = ∂Hx∂y −∂Hy∂x

H - magnetic fieldJ - current densityJc - critical currentdensityn - exponent ofpower law, assumedas 31 [1]x , y , z - geometricalaxesE0 - electric fieldthreshold

1Kvitkovic et al., 2018


Methods

Critical current density

Critical cu

rrent

of a sin

gle tape

,A


Results

Contents

1 Introduction

2 Methods

3 Results

4 Conclusions


Results

Magnetisation

Magnetic induction in T and magnetic vector potential in Wb/m


Results

Current density

Current density in A/m2


Results

Operation

Voltage response of a coil in V


Results

Anisotropic heat transfer in optimised configuration

Temperature and heat transfer direction in a section of aconduction-cooled rotor


Conclusions

Contents

1 Introduction

2 Methods

3 Results

4 Conclusions


Conclusions

Conclusions

The shape of stacks is selected and they will bemanufactured soonFurther thermal analysis will be performed to find optimalmounting methodResearch on protection against demagnetisation isongoingThe results from the operation of a demonstrator motor willbe available in 1Q 2020


Conclusions

Acknowledgements

This research is financially supported partially by the EuropeanUnion’s Horizon 2020 research innovation programme undergrant agreement No. 7231119 (ASuMED "AdvancedSuperconducting Motor Experimental Demonstrator") and alsoby EPSRC grant No. EP/P000738/1 entitled "Development ofsuperconducting composite permanent magnets forsynchronous motors: an enabling technology for future electricaircraft".


Conclusions

Conclusions

The shape of stacks is selected and they will bemanufactured soonFurther thermal analysis will be performed to find optimalmounting methodResearch on protection against demagnetisation isongoingThe results from the operation of a demonstrator motor willbe available in 1Q 2020

IntroductionMethodsResultsConclusions

coupled electromagnetic-thermal model of a superconducting … · 2019. 12. 23. · superconducting...

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