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Superconducting Transformers Prof. Dr.-Ing. Mathias Noe, Karlsruhe Institute of Technology Institute for Technical Physics EUCAS Short Course Power Applications, September 17th 2017., Geneva KIT-ENERGY CENTRE KIT The research University in the Helmholtz Association www.kit.edu

Motivation of Superconducting Transformers Motivation Different Types A few Basics State of the Art Applications Summary 2 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Manufacturing and transport Compact and lightweight (~50 % Reduction) 30 MVA Transformers conventionel superconducting Waukesha 3 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Manufacturing and transport Compact and lightweight (~50 % Reduction) Environment and Marketing Energy savings (~50 % Reduction) Ressource savings Conventionel 400 MVA Transformer ABB 4 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Manufacturing and transport Compact and lightweight (~50 % Reduction) Environment and Marketing Energy savings (~50 % Reduction) Ressource savings Inflammable (no oil) 5 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Manufacturing and transport Compact and lightweight (~50 % Reduction) Environment and Marketing Energy savings (~50 % Reduction) Ressource savings Inflammable (no oil) Operation Low short circuit impedance Higher stability Less voltage drops Less reactive power Active current limitation Protection of devices Reduction of investment 6 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Manufacturing and transport Compact and lightweight (~50 % Reduction) Environment and Marketing Energy savings (~50 % Reduction) Ressource savings Inflammable (no oil) I I p I p,lim Operation Low short-circuit impedance - Higher stability - Less voltage drops - Less reactive power Active current limitation - Protection of devices - Reduction of investment 7 M. Noe, EUCAS Short Course, Superconducting Transformers I c I r t lim Enables a new class of transformers t rec t

Motivation of Superconducting Transformers Motivation Different Types A few Basics State of the Art Applications Summary 8 M. Noe, EUCAS Short Course, Superconducting Transformers

Different TypesofSuperconducting Transformers Warm Iron Core LN 2 Iron Core Cold Iron Core Conduction Cooled Coldhead LN 2 Iron Core Iron Core Cryostat LN 2 Iron Core Vacuum Cryostat Cryostat Low Cooling Power Iron at Room Temperature Expensive Cryostat 3 Cryostats needed Simple Cryostat Simple Cooling inerface High Cooling Power (Iron core loss at low temp.) Simple Cryostat Iron at Room Temperature Long recooling after quench Temperature difference Not suitable for high voltage 9 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Motivation Different Types A few Basics State of the Art Applications Summary 10 M. Noe, EUCAS Short Course, Superconducting Transformers

Transformer FluxLinkage Stray flux Stray flux Main flux 11 M. Noe, EUCAS Short Course, Superconducting Transformers

Transformer Inductances OS Main Inductance A M US A Fe A M d Fe a a a w a i b us b os b M a h OS US US OS Stray Inductance h w z r h F h T a h b M b F d Fe b T 12 M. Noe, EUCAS Short Course, Superconducting Transformers

Electrical Circuit f H : main flux f σ : stray flux R 1 : resistance primary winding L 1σ : Stray inductance primary winding R 2`: resistance secondary winding L 2σ`: Stray inductance secondary winding L h : main inductance R FE : iron core loss I 1 R 1 L 1σ L 2σ R I 2 2 U U 1 2 R FE I 0 L h What is different between normal and superconducting transformers? 13 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Motivation Different Types A few Basics State of the Art Applications Summary 14 M. Noe, EUCAS Short Course, Superconducting Transformers

History of LTS Transformers Year Organization Country Power in kva Data 1985 GEC-Alstom F 80 660V/1040V 124A/77A 1988 Kyushu University J 72 1057V/218V 68A/332A 1991 Toshiba J 30 100V/100V 300A/300A 1991 Ktio J 100 6600V/210V 15A/476A 1992 Kyushu University J 1000 3300V/220V 303A/4545A 1993 ABB CH 330 6000V/400V 56A/830A 1995 Osaka University J 40 460V/150V 50A/200A Voltage per winding Supercond. 2,14 V NbTi - NbTi - NbTi 4,57 V Cu/NbTi 10 V NbTi 7,9 V NbTi 0,45 V NbTi Source: Technik und Einsatz von HTSL Leistungstransformatoren, Diss. E. Sissimatos 2005 15 M. Noe, EUCAS Short Course, Superconducting Transformers

630 kva Transformer (ABB) Worldwide first field test of a superconducting transformer Power 630 kva Voltage 18 720 / 420 V Group Dyn11 Frequency 50 Hz Short circuit impedance 4,6% Current 11,2 / 866 Superconductor Bi 2223 Cooling LN 2 bei 77 K V Losses at I r 337 W @ 77 K Quelle: H. Zueger et al, Cryogenics 1998 Volume 38, Number 11 16 M. Noe, EUCAS Short Course, Superconducting Transformers

1 MVA Transformers 1996 (Kyushu) Rated power: 1 MVA Rated Voltage: 22/6,9 kv Frequency: 60 Hz Short circuit voltage: u k = 5 % Cooling: subcooled LN 2 at 64 K Volume: 1,5 m x 1,2 m x 2,7 m (l x w x h) Weight: 5100 kg Bi 2223 Superconductor Losses: 160 W bei 65 K Successful Field Test Quelle: Kimura et al Physica C 372-376, 2002-S. 1694-1697 17 M. Noe, EUCAS Short Course, Superconducting Transformers

1 MVA Mobile Transformer 2001 (Siemens) RatedPower: 1 MVA Rated Voltage: 25/1,4 kv Frequency: 50 Hz SC impedance : u k = 25 % Cooling LN 2 at 67 K Volume: 0,88 m x 0,406 m x 1,08 m (l x w x h) Weight active part: 1010 kg WeightLN 2 Tank: 272 kg LengthBi 2223 tapes: 6,8 km Losses: 1960 W bei 67 K Efficiency: η = 97,75 % 1080 mm Efficiency of normal train transformers: η = 92 95 % 880 mm 18 M. Noe, EUCAS Short Course, Superconducting Transformers

1 MVA Mobile Transformer 2001 (Siemens) Losses Iron Core 700 W Stray field (Iron) 280 W Winding and current leads 780 W Thermal losses 200 W Total loss 1960 W @ 67 K Total loss 23 kw @ RT Efficiency supercond. 97,75% Efficiency normal 92-95 % Transformer installed in frame 19 M. Noe, EUCAS Short Course, Superconducting Transformers

1 MVA Mobile Transformer - 2001 (Siemens) HTS-Train transformer left Normal train transformer right HTS-Transformer in test field 20 M. Noe, EUCAS Short Course, Superconducting Transformers

Major HTS Transformers Projects Country Inst. Application Data Phase Year HTS Switzerland ABB Distribution 630 kva, 18,42 kv/420v 3 Dyn11 1996 Bi 2223 Japan Fuji Electric Demonstrator 500 kva, 6,6 kv/3,3 kv 1 1998 Bi 2223 Germany Siemens Demonstrator 100 kva, 5,5 kv/1,1 kv 1 1999 Bi 2223 USA Waukesha Demonstrator 1 MVA, 13,8 kv/6,9 kv 1 Bi 2223 USA Waukesha Demonstrator 5 MVA, 24,9 kv/4,2 kv 3 Dy Bi 2223 Japan Fuji Electric Demonstrator 1 MVA, 22 kv/6,9 kv 1 2001 Bi 2223 Germany Siemens Railway 1 MVA, 25 kv/1,4 kv 1 2001 Bi 2223 EU CNRS Demonstrator 41 kva, 2050 V/410 V 1 2003 P YBCO/S Bi 2223 Korea U Seoul Demonstrator 1 MVA, 22,9 kv/6,6 kv 1 2004 Bi 2223 Japan Fuji Electric Railway 4 MVA, 25 kv/1.2 kv 1 2004 Bi 2223 Japan Kuyshu Uni. Demonstrator 2 MVA, 66 kv/6.9 kv 1 2004 Bi 2223 China IEE CAS Demonstrator 630 kva, 10.5 kv/400 V 3 2005 Bi 2223 Japan U Nagoya Demonstrator 2 MVA, 22 kv/6,6 kv 1 2009 P Bi 2223/S YBCO Japan Kyushu Uni Demonstrator 400 kva, 6.9 kv/2.3 kv 1 2010 YBCO Germany KIT Demonstrator 60 kva, 1 kv/600 V 1 2010 P Cu/S YBCO USA Waukesha Prototype 28 MVA, 69 kv 3 Not completed YBCO Australia Callaghan Demonstrator 1 MVA, 11 kv/415 V 3 Dy 2013 YBCO Innovation China IEE CAS Demonstrator 1.25 MVA, 10.5 kv/400 V 3 Yyn0 2014 Bi 2223 Germany KIT/ABB Demonstrator 577 kva, 20 kv/1 kv 1 2015 P Cu/S YBCO 21 M. Noe, EUCAS Short Course, Superconducting Transformers

Current Limiting Transformer 2013 Objective: Develop and field test a 1 MVA HTS transformer using YBCOa Project Partners: Gallaghan Innovation, Wilson Transformers, General Cable Parameter Primary Voltage Secondary Voltage Maximum Op. Temp. Target Rating Primary Connection Secondary Connection LV Winding LV Rated current HV Winding HV Rated current Value 11,000 V 415 V 70 K, liquid nitrogen cooling 1 MVA Delta Wye 20 turns 15/5 Roebel cable per phase (20 turn single layer solenoid winding) 1390 A rms 918 turns of 4 mm YBCO wire per phase (24 double pancakes of 38.25 turns each) 30 A rms Source: Gallaghan Innovation First HTS Roebel wire in field test 22 M. Noe, EUCAS Short Course, Superconducting Transformers

Current Limiting Transformer - 2013 Objective: Develop and field test a 1 MVA HTS transformer using YBCOa Project Partners: IRL, Wilson Transformers, General Cable HV Winding LV Winding 4 mm wide YBCO I/I c ~ 25% Polyimide wrap insulation 24 double pancakes YBCO Roebel Cable L = 20 m 15 strands 5 mm width I c ~ 1400 A @ 77 K, sf Source: Igallaghan Innovation More information: Neil D. Glasson, Mike P. Staines, Zhenan Jiang, and Nathan S. Allpress, Verification Testing for a 1 MVA 3-Phase Demonstration Transformer Using 2G-HTS Roebel Cable, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 23, NO. 3, JUNE 2013 23 M. Noe, EUCAS Short Course, Superconducting Transformers

Current Limiting Transformer 2013 Objective: Develop and field test a 1 MVA HTS transformer using YBCOa Source Cryostat Electrical bushing AC loss in LV AC loss in HV Total Heat load 113 W 343 W 390 W 90 W 936 W Efficiency at 100% load: ~ 97% Efficiency at 50% load 98.5 % Current standard Efficiency at 50% 99.27% Source: Gallaghan Innovation More information: Neil D. Glasson, Mike P. Staines, Zhenan Jiang, and Nathan S. Allpress, Verification Testing for a 1 MVA 3-Phase Demonstration Transformer Using 2G-HTS Roebel Cable, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 23, NO. 3, JUNE 2013 24 M. Noe, EUCAS Short Course, Superconducting Transformers

Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer 02.06.2017, Karlsruhe Sebastian Hellmann (KIT) / Markus Abplanalp (ABB) Institute for Technical Physics (ITEP) KIT The Research University in the Helmholtz Association www.kit.edu

Introduction 60kVA Transformer KIT developed a 60 kva laboratory demonstrator facilitating a superconducting secondary winding to limit fault currents superconducting secondary winding normal-conducting primary winding laminated iron core 26 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

Introduction 60kVA Transformer superconducting secondary winding laminated iron core normal-conducting primary winding Main transformer parameters power 60 kva ratio 100 / 60 (turns) voltage 1 kv / 600 V currents 60 A / 100 A j prim 5 A / mm 2 j sec 83.3 A / mm 2 u k 1.58% 27 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

Introduction 60kVA Transformer Recovery-under-Load (RuL) measurement for I rec = I nom = 100 A t lim = 60 ms t rec 2.3 s 28 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

Transformer Design Fix Main transformer parameters: Name Unit symbol Value Unit Nominal power P nom 577.4 kva Primary winding (normal-conducting winding) Secondary winding (superconducting winding) U prim 20 kv I prim 28.9 A U sec 1 kv I sec 577.4 A Fault duration t fault 60 ms Current limitation 1st HW I LIM, 1HW 13.55 ka Limitation 1st HW in resp. to prosp. current LIM 1HW 71.4 % Current limitation 6th HW I LIM, 6HW 6.5 ka Limitation 6th HW in resp. to prosp. current LIM 6HW 35.7 % 29 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

Transformer Design Fix The design of the transformer is focusing on technology demonstration and includes practical compromises such as: Non-optimal cryogenic design Relatively short current leads Non-sealed cryogenic environment No automatic LN 2 level control 30 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

Transformer Design Fix 31 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

Measurements Current limitation Prospective current and limited current (simulated and measured) with 25.3 mω short-circuit: 32 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

- Thank you for your Attention - Sebastian Hellmann / KIT / sebastian.hellmann@kit.edu 33 14.09.2017 Sebastian Hellmann Manufacturing and Test of a 1MVA-Class Superconducting Fault Current Limiting Transformer Institute for Technical Physics (ITEP)

One slide about economics of transformers Cost range of conventional transfomers 1 MVA ~ 30.000 US$ 50 MVA ~ 730.000 US$ Source: Large power transformers and the U.S. electric grid, Infrastructure Security and Energy Restoration Office of Electricity Delivery and Energy Reliability, U.S. Department of Energy, June 2012 Assumption: 300 m HTS per MVA and phase 30 /m HTS wire, 4 mm wide 30 k for a km 10 MVA 9 km, 4 mm wide 270 k for HTS wire 100 MVA 90 km, 4 mm wide 2.7 Mio. for HTS wire 34 Institute for Technical Physics (ITEP)

Motivation of Superconducting Transformers Motivation Different Types A few Basics State of the Art Applications Summary 35 M. Noe, EUCAS Short Course, Superconducting Transformers

Application of Transformers? Auxiliary transformer A) B) EHV 380 kv C) HSV110 kv Networktransformer Generatortransformer Distributiontransformer D) MV 10 30 kv E) Substation transformer LV 0,4 kv Many potential applications but which one is attractive enough? 36 M. Noe, EUCAS Short Course, Superconducting Transformers

Application of Transformers? You are lucky and you can choose any application for a superconducting transformer. With which application would you start? A. Auxiliary transformer B. Generator transformer C. Network transformer D. Distribution transformer E. Substation transformer F. Mobile transformer G. Any other transformer H. I have no idea 4% 17% 30% 22% 9% 4% 0% 13% Auxiliary transformer Generator transformer Network transformer Distribution transformer Substation transformer Mobile transformer Any other transformer I have no idea 37 M. Noe, EUCAS Short Course, Superconducting Transformers

Motivation of Superconducting Transformers Motivation Different Types A few Basics State of the Art Applications Summary 38 M. Noe, EUCAS Short Course, Superconducting Transformers

Status of Superconducting Transformers o o o o Successful technology development in recent years mainly with YBCO wires Successful demonstrator development with a rating up to 4 MVA and medium voltages Only a few grid tests have been taken place Time seems ready for more 3 phase medium voltage demonstrators and prototypes for long term field tests 39 M. Noe, EUCAS Short Course, Superconducting Transformers

A final remark 400 tons 6 Mio US$ Superconducting transformers are attractive but do not solve all transformer challenges! 40 M. Noe, EUCAS Short Course, Superconducting Transformers