« Supraconductivité » Mai 2009 Update IEA : Fault Current Limiters and Superconducting Generators

1. « Supraconductivité »Mai 2009Update IEA : Fault Current Limiters and Superconducting Generators Julian Cave

2. High Temperature Superconductivity • Copper, aluminium and Iron • rising costs • Network losses are important • rising electricity costs • Stability and capacity – what are the limits? • increasing demand • Heat, Dielectrics, Ageing, Lifetime • Price targets for superconductying wires ~10$/kAm • costs are falling, capacity and length is increasing • Reliable and efficient Cryogenics • High capacity GM and Pulse Tubes

3. Evaluation of Fault Current Limiters for Power Utilities Using EMTP-RV IREQ HYDRO-QUEBEC 1800 boul. Lionel-Boulet, Varennes, Québec, Canada, J3X 1S1 ?

4. rt rff rr r2 , E2 , n/m2 r1 , E1 , n/m1 rs , Es , n Resistivity Model * where i = s,1,2 Special E-J power law with several segments with increasing values of electric field, E2>E1>Es, and corresponding scaled values of the power exponent n by constants m. Improved modeling of flux flow Substrate (effective transfer resistivity) Flux-Flow (T and B dependences) Residual Flux-Flow (high electric field) Resistivity Flux-Flow (low electric field) Onset resistivity (critical electric field) Ref : J. Cave, V. Sood : ICMC 2007, Chattanooga * And : J. Cave … to be submitted

5. Temperature Sweep Test (simulation) r E J J (Temperature swept from 50K to 100K (Ba=1mT) whilst J varies sinusoidally) Curves do not cross each other! n T Ref : J. Cave, V. Sood : ICMC 2007, Chattanooga

6. Simulation of a 2G wire Limiter YBCO 2G limiting element 20cm wide (e.g. 20 1cm tapes in parallel) and 400 metres long; the superconductor is 1 mm thick and the stabilizer with substrate is 400 mms thick. The critical current is 2300 A at 77K (giving Jc just over 1MA/cm2) Ref : J. Cave, V. Sood : ICMC 2007, Chattanooga

7. Basic Superconducting Module • The Basic Module contains all the thermo-electromagnetic equations • There are input and output connections for the Current and Temperature so that several modules can be connected together to represent different types of limiting elements Included are tabulated typical property variations : X, Y X Jc, n, Tc, rn Y Asc Quality index input

8. Limiter with Separated Elements (modular limiter) 75kV • A multiple series • and parallel element • limiter with • interconnections • 100 ms Fault • A3 has degraded properties Interconnect Quality indices

9. Elements made from 2G YBCO wire 800 Current avoids A3 Temperature of each element (To = 77K, FS 220K) Current in each interconnection 8000 Current in each element -8000 • Principal Characteristics • ~ 1mm thick • High Jc at 77K ~ MA/cm2 • Large ratio stabilizing material to superconductor ~ 400

10. Thermally Coupled Modules (materials variation) • Configuration for a variation of properties along the length of a fault current limiting module • By referencing the temperature of A to B and of B to A only two blocks need to be solved • This represents an infinitely repeated ABABABABAB …. element • The thermal coupling strength of B to A can be varied to model local to long range thermal transfer IN OUT Variable coupling Tabulated property variations : X, Y Jc, n, Tc, rn Asc … the properties of the A and B sections can be altered by using the quality index input(s) PASREG Cambridge

11. Varying materials properties: 15kV limiter 20cm total width, Ic ~ 2000A 20% reduction in Asc (using Y) …….…heat transfer…….. ….. …… A B A B A B A B A B A B A B ASC Chicago

12. A B 200m + 200m (-20% Asc) limiter no coupling I V T(K) Recovery ~ 4s B A

13. 200m + 200m (-20% Asc) limiter strong coupling I V T(K) Recovery ~ 4s B Closer temperature profiles A

14. 400m + 400m no Asc variation limiter : Ideal * Limits on V-I curve T<Tc I V ~Tc T(K) * materials and cost challenge! A, B same, very quick recovery Tmax<Tc Recovery ~ 1/4s A, B same

15. Example Saturated Iron Core Limiter

16. Evaluation of Hydro-Generators for Power Utilities Using Finite Elements, Mathematica and EMTP-RV J. R. CAVE, François Beauregard, Omar Saad and Francis Talbot (Student Project)

17. Classique Rotor vs. Superconducting Rotor Materials Limits : • Copper / Aluminium : 103 A/cm2 • Iron : 2 T • SC wires : Jc : 106 A/cm2 • SC coils : 10 T+ Classic Rotor Dimensional compromises Superconducting Rotorteur Flexible dimensions, With/without iron for rotor, stator teeth and even stator

18. Project description • Goal: To modelize and simulate a synchronous supra machine • To fully understand the behaviour of this kind of machine • To evaluate if the performances obtained with it worth its use in the network

19. Student Project : Francis Talbot

20. Software tools • MagNet: • Physical objects modelization (AC machines) using FE (Finite Elements) • Mathematica • Powerful calculation software that includes multiple elaborate functions • EMTP: • Electrical circuit simulation software specialized in power electronic • Simulation of the machine (EMTP) • Simulate the machine… • using its “dq0” parameters in PU (per unit) OR • using its IEEE 115 tested parameters ( ) • Simulate the network around the machine to validate its behaviour

21. MagNetChoix du rotor EssaiFormeFlux (phase A) #1 #2

22. MagNetChoix du rotor EssaiFormeFlux (phase A) #7

23. New Software Tools for generators Output Flux Data Build Model Fitting Parameters

24. Example Superconducting Rotor

25. More Example Rotors

26. Example Field Penetration C++ programming of dlls for commercial FE software

27. Examples Multiphysics (FlexPDE) Can write your own equations See Archie Campbell recent publications

28. Canada • Frederic Sirois, Ecole Polytechnique • International HTS regroupment for modelling properties - funding approved MITACS