Our Publications and Tutorials

Trafoexperts Transformer Consulting Services

Identification of partial discharges in power transformers: An approach driven by practical experience
S. Ganeshan; J. Murugesan; A. Cavallini; F. Negri; B. Valecillos; U. Piovan
Electrical Insulation Magazine, IEEE (Volume 33, Issue 5) Sept.-Oct. 2017

HVDC Transformer Insulation: Oil Conductivity
A. Küchler, U. Piovan, M. Berglund, G. Chen, A. Denat, J. Fabian, R. Fritsche, T. Grav, S. Gubanski, M. Kadowaki, Ch. Krause, A. Langens, S. Mori, B. Noirhomme, H. Okubo, M. Rösner, J. Schiessling, F. Schober, P. Smith, P. Wedin
2016, CIGRE Brochure 646

A comparison of the voltage withstand properties of ester and mineral oils
C.G. Azcarraga, A. Cavallini, U. Piovan
Electrical Insulation Magazine, IEEE (Volume 30, Issue 5) Sept.-Oct. 2014

Insulation systems for HVDC transformers: present configurations, trends, challenges, solutions and open points
U. Piovan
11th IEEE International Conference on Solid Dielectrics – June 30th – July 4th 2013 Bologna, Italy

Mineral Oil Electrical Conductivity and Field Grading in Insulation Systems for HVDC Converter Transformers
U. Piovan, C. Krause and G. Schenk
Feldsteuernde Isoliersysteme , Werkstoffe, Design, Prüfung und Simulation – Vorträge des ETG Workshops, Darmstadt 22.11.2011 Germany

Review of requirements and diagnostics of oil/board DC-insulation systems
Fabian, J. ; Woschitz, R. ; Muhr, M. ; Krause, C. ; Piovan, U.
IEEE International Conference on Dielectric Liquids (ICDL), 2011 Trondheim, Norway

Transient Behaviour of Power Transformers, Detail Modelling
Baudilio Valecillos
ARWtr2010. Advanced Research Workshop on Transformers. 3-6 October 2010. Santiago de Compostela Spain

1200kV Transformer Lead Exit challenges and solutions
Ugo Piovan
International Conference On 1200kV NATIONAL TEST STATION
2010, New Delhi, INDIA

Evaluation of Conductivities and Dielectric Properties for Highly Stressed HVDC Insulating Materials
CIGRE 2010 Session, Paris

HVDC Converter Transformers – Design review, test procedures, ageing evaluation and reliability in service
M. Saravolac, G. M. Bastos, N. Dhaliwal, S. E. Santo, T. Freyhult, Y. H. Fu, J. Hajek, A.C. Hall, P. Heinzig, U. Piovan, V. Prasher, S. Yukiyasu.
2010, CIGRE Brochure 406

HVDC Converter Transformers – Guidelines for conducting design reviews for HVDC converter transformers
M. Saravolac, G. M. Bastos, N. Dhaliwal, S. E. Santo, T. Freyhult, Y. H. Fu, J. Hajek, A.C. Hall, P. Heinzig, U. Piovan, V. Prasher, S. Yukiyasu.
2010, CIGRE Brochure 407

Effects Of Variability Of Mineral Oil Electrical Conductivity On Reliability of HVDC Converter Transformers
U. Piovan, G. Schenk
TRAFOTECH-2010 Mumbai

Building Reliable AC and DC UHV Power Transformers – Dielectric Design Principles, Suitable Pressboard Insulation and Issues Related to HVDC Testing
Ch. Krause, U. Piovan, D. Tschudi
International Conference on UHV Transmission, Beijing, China, 2009

Dielectric Response Measurement of a Power Transformer under variable temperature
B. Valecillos, J.C. Burgos. B. García
XVth International Symposium on High Voltage Engineering, Ljubljana Slovenia August 27-31, 2007

Evaluation of lightning Impulse Test by Frequency Response Analysis
B. Valecillos, J. Ramírez
2006 IEEE PES Transmission and Distribution Conference and Exposition Latin America. Caracas, Venezuela 15-18 de Agosto 2006

Optimization of a brushless DC drive by change of power electronic control parametersand motor geometry
U. Piovan, B. Forghani, D. Dyck, Phillip Weicker, M. Negro, L. De Fina
INDUCTICA 2006, Berlin

Optimization of eddy current sensors in the MHz range using a FEM model of proximity effects
F. Baumgartner, L. De Fina, B. Forghani, R. Galdi, R. Grabherr, M. Hefit, M. Negro, U. Piovan
INDUCTICA 2006, Berlin

Challenges in Dielectric Insulation of HVDC Transformers above 600 KV
U. Piovan, G. Schenk
Colloquium on Role of HVDC, FACTS and Emerging Technologies in Evolving Power Systems, 2005; Bangalore

Models of Grounding Systems under Lightning Discharges. Simple Electrode Configurations
Ramírez J., Davila S. Valecillos B. Martínez M. Rodríguez J.C. Da silva E. Velazco J.
CLP International Conference on Lightning Protection. Avignon, France 13-16 September 2004

HVDC Tutorial at IEEE Transformer Committee Fall meeting
U. Piovan
Las Vegas, 2004

Optimal shape design of a multiple-coil device for induction heating
P. Di Barba, B. Forghani, M. Negro, U. Piovan
INDUCTICA 2004, Berlin, Germany

Export of MagNet 3D models and fields to VRML
Roberto Galdi, Ugo Piovan
Presented at Infolytica User Group Meeting 2003, Montreal, Quebec

An Industrial Approach to Discrete Optimization
P. Di Barba, R. Galdi, A. Savini, D. Dyck, S. Lalonde, U. Piovan
Presented at Infolytica User Group Meeting 2003, Montreal, Quebec

Optimal shape design of a high-voltage test arrangement
P. Di Barba, R. Galdi, U. Piovan, A Savini, G. Consogno
COMPEL: Int. J. for Computation and Maths. in Electrical and Electronic Eng.
Year: 2004 Volume: 23 Number: 3 Page: 633 — 638

Impact of dielectric material responses on the performance of HVDC power transformer insulation
A. Küchler, F. Huellmantel, J. Hoppe, D. Jahnel, C. Krause, U. Piovan, N. Koch
13th Int. Symp. On High voltage Engineering, Delft, NL, 2003

Optimal shape design of industrial electromagnetic devices using both continuous and discrete-valued variables
P. Di Barba, B. Forghani , D.A. Lowther, M. Negro, U. Piovan, A. Savini

Design Optimization of Transformer Insulation
A. Bramanti, P. Di Barba, U. Piovan, A. Savini
ISEF 2001 – 10th International Symposium on Electromagnetic Fields in Electrical Engineering, Cracow, Poland, September 20-22, 2001

Field simulation of forces on windings in a transformer for arc furnace
P. Di Barba, M.Farina, U. Piovan, and A. Savini
COMPEL International Journal for computation and mathematics in Electrical and Electronic Engineering, 19(2):381–387, 2000. SCP

The complete symbolic factorisation for the security analysis of power systems
A.Berizzi, R.Pavani, U.Piovan, A.Silvestri, D.Zaninelli.
ETEP, vol.8, no.3, May/June 1998

Dr. Ing. Ugo Piovan

Dr. Ing. Ugo Piovan

Transformer Consultant
Trafoexperts GmbH

Turbinenweg, 4
8610, Uster, Switzerland