The transformer as a whole Dr. Michael Schäfer TransnetBW GmbH TRANSFORM Partner
Introduction Michael Schäfer University of Stuttgart: Electrical machines and high voltage technology 2000: PhD Thermal monitoring of power transformers 2006 : Siemens AG in Nuremberg, transformer factory, R&D, sales and project management 2011: EnBW Regional AG, (DSO) substation components and technology Since 2011 TransnetBW GmbH (TSO) substation technology, operation of secondary technology Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 2
Content Fundamentals History Working principle Engineering and design of transformers Operation conditions of transformers in power grids Examples of different designs Main materials and components Innovations and trends Smart and green transformers New applications Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 3
First transformers 1884: Bláthy, Déri und Zipernnowsky 1882: Gulard, Gibbs 1885: Stanley Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 4
Classification by applications of transformers Measurement of el. values Information transmission Power transmission Accuracy Frequency, size Loss, weight Transformers based on the same physical principle are available from 10-6 to 10 9 VA Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 5
Working principle - two electrical circuits connected by a magnetic circuit - no moving parts - energy transmission via magnetic field (flux) in the windings W 1 W 2 1 I 1 U 1 U 2 - power transformers have a very high efficiency (>99%) and a long operation time (>40 years) Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 6
Physical background single phase transformer I h II h i 1 i 2 u 1 u 2 1 2 Main Flux: h = B Fe * A, magnetic field strength H Fe = B Fe / μ Fe Inductances: 1 = i 1* L 1s, 2 = i 2* L 2s, 1h = (i 1 -i 2 ) * L h Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 7
Physical principle and equivalent circuit Resistances for power loss Inductances for magnetic flux connections h i 1 R 1 L 1 ' L 2 R 2 i 2 i m 1 2 u 1 u 2 R h L 1h di idi 1 1 2 u1 Ri 11L1 Lh dt dt P U/ R Fe 2 h Fe id 2 idi 12 u2 Ri 22L2 Lh dt dt Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 8
From a single phase transformer to a three phase transformer U U U U W U V W V a) Three single phase transformers b) Three phase transformer symmetric core h J h' J < h J c) Three phase transformer three legs d) Three phase transformer five legs Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 9
Transformers in power grids 0 Hz System transformer HVDC transformer EHV transmission grid 220-1.000kV HV distribution grid 66-170kV MV distribution grid system interconnection Generator transformers reactors special industrial transformer 6-50kV 50 Hz 16,7 Hz oil distribution transformer dry type transformer traction transformer Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 10
Various applications and numerous variations of designs small overview Generation Transmission Industry Distribution Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 11
Specification parameters and their influence on the design of a transformer Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 12
Examples of different designs of 300 MVA 405/115kV system interconnecting transformers 2003 2009 1974 Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 13
Main materials: The cellulose oil insulation system polar molecules - cellulose molecules without polarity - oil stresses: - forces - temperature - dielectric - humidity - acids Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 14
Main materials: Core and conductor material stresses: - forces - temperature - dielectric Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 15
Components: Tap changer and line terminals linear reverse coarse-fine 245 kv Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 16
Change drivers - new materials and components - new applications - environmental issues political trends - competition and market development solutions demand product and market development 1912 2012 Priorities: Technical Commercial Commercial Environment Commercial Technical Environment Commercial Environment Environment Technical Technical Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 17
New applications: Large high - deep 800kV HVDC ABB Siemens ABB EnBW Offshore applications Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 18
Future developments and trends according the new priorities 1) Environment 2) Commercial 3) Technical transformers in HVDC systems and FACTS natural ester insulation liquid offshore windfarm Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 19
Summary - history, power range and physical principle are described - transformer designs need to follow various boundary conditions large transformers are individuals - main materials and components are still under development - priorities are changing; technical > commercial > environmental Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 20
EW Aach - Introduction is the TSO of France Weier Philippsburg Neurott Daxlanden Karlsruhe Neckarwestheim Krh-Ost Oberwald SÜWAG Birkenfeld Hoheneck Pulverdingen Mühlhausen Kuppenheim Weil- See- Endersbach TWS wiesen imdorf Altbach Bühl Altlußheim Oberjettingen amprion Heidelberg Obrigheim Wiesloch Großgartach Hüffenhardt Heilbronn Möhringen Wendlingen Metzingen Höpfingen Kupferzell Bünzwangen Goldshöfe Niederstotzingen Rotensohl Area 34.600 km² System length 3.239 km Voltage range 220 kv 380kV Employees 350 Peak load approx. 11 GVA Laichingen RTE Engstlatt Dellmensingen TenneT Eichstetten Villingen Trossingen Stockach Wehr RWE E Gurtweil Grünkraut Kühmoos Tiengen Obermooweiler Schwörstadt Laufenburg Swissgrid Switzerland Werben Meinigen Bürs Austria APG Dr. Michael Schäfer, TransnetBW GmbH 06.06.2013 Page 21