Laboratory for electromagnetic fields

Welcome to the web page of the Laboratory for electromagnetic fields (EMLAB) of University of Zagreb, Faculty of electrical engineering and computing.


News

5th International Colloquium...

Faculty of Electrical Engineering and Computing in Zagreb and the Centre of Excellence for Transformers in Zagreb successfully organized the 5th International Colloquium "Transformer Research and Asset Management". The Colloquium was held in Opatija, Croatia, from October 9 to 12, 2019.


The Colloquium included three tutorials „Moisture Measurement in Insulating Fluids and Transformer Insulation – an Evaluation of Solid State Sensors and Chemical Methods“ by Ivanka Atanasova-Hoehlein and Tim Gradnik, „Condition Assessment of Power transformers“ by Brian Sparling, and „Transformer Post-Mortem Analysis“ by Andrew Fieldsend-Roxborough, as well as the presentation of more than 50 papers in poster and oral sessions.


Papers "Influence of conductor transposition on transformer winding RLC parameters" by Ana Drandić, Bojan Trkulja, and Željko Štih, and "Calculation of Eddy current losses in iron core of transformer" by Stjepan Frljić, Bojan Trkulja, and Željko Štih were presented during the Colloquium.


Details about colloquium together with photos can be found here.

Author: Ana Drandić
SMAGRIMET 2018

Faculty of Electrical Engineering and Computing in Zagreb, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture in Split and International Council On Large Electric Systems  (CIGRÉ) -  Croatian National Committee succesfully organized the  First International Colloquium on Smart Grid Metrology 2018 (SMAGRIMET 2018). The Colloquium was held in Split, Croatia, from April 24 to 27, 2018.

Bojan Trkulja presented the paper entitled: "Computation of Self- and Mutual Inductances of Open-core Transformers Using a 3D Integral Equations Approach" by Bojan Trkulja, Stjepan Frljić, Ana Drandić, Igor Žiger, and Željko Štih at the Colloquium.

During the Colloquium, several paper written by Martin Dadić and co-workers were presented, including: „FIR Modeling of Voltage Instrument Transformers from Frequency Response Data“ by Martin Dadić, Tomislav Župan and Gabrijel Kolar, and „A Circular Loop Time Constant Standard for the Determination of Phase Angle Errors of Current Shunts“ by Martin Dadić, Monika Sandelić, Hrvoje Hegeduš and Goran Petrović.

Details about colloquium can be found at smagrimet.org.

Author: Ana Drandić
EMF 2018

The 11th International Symposium on Electric and Magnetic Fields, EMF 2018, took place in Darmstadt, Germany, from 10 to 12 April 2018.

Ana Drandić presented the paper: "Computation of transformer capacitance matrix with 3D BEM and adaptive cross approximation" by Ana Drandić and Bojan Trkulja, and Stjepan Frljić presented the paper: "2D Method for Calculation of Eddy Current Losses in Laminated Core of Transformer" by Stjepan Frljić and Bojan Trkulja.

Author: Ana Drandić
ELECO 2017

ELECO 2017, 10th International Conference on Electrical and Electronics Engineering was held in Bursa, Turkey, 30th November - 2nd December 2017.

Bojan Trkulja presented the paper entitled: "Calculation of Self- and Mutual Inductances of Power Transformers Using a 3D Modified Magnetostatic Integral Equation Approach" authored by Bojan Trkulja, Željko Štih and Tomislav Župan - Končar - Institut za elektrotehniku.

Author: Bojan Trkulja
4th International Colloquium...

Faculty of Electrical Engineering and Computing in Zagreb and the Centre of Excellence for Transformers in Zagreb succesfully organized the 4th International Colloquium "Transformer Research and Asset Management". The Colloquium was held in Pula, Croatia, from May 10 to 12, 2017.


The Colloquium included two tutorials „Transformer Bushing Reliability“ by Antun Mikulecky and „Dynamic Testing for On Load Tap Changer Condition Assessment“ by Raka Levi, as well as the presentation of more than 60 papers in poster and oral sessions.


Papers "Power transformer winding model for lightning impulse testing" by Tomislav Župan, Bojan Trkulja, and Željko Štih, "Transformer electric field calculation using BEM and FEM" by Ana Drandić, Bojan Trkulja, and Željko Štih, and "Development of 3D BEM code for computation of a transformer Winding’s capacitance matrix" by Bojan Trkulja, Ana Drandić, and Željko Štih were presented during the Colloquium.

 

Details about colloquium together with photos can be found here.

Author: Ana Drandić
SCEE 2016 in St.Wolfgang, Austria

SCEE 2016 - the 11th International Conference on Scientific Computing in Electrical Engineering took place at the St. Wolfgang Federal Institute for Adult Education from  3-7th October 2016.
The paper entitled "Computation of electric field in transformers by boundary element method and fast multipole method" by Ana Drandić and Bojan Trkulja was presented at the conference.

Author: Ana Drandić
17th IGTE Symposium held in Graz,...

Dr.sc. Tomislav Župan attended the "17th International IGTE Symposium on Numerical Field Calculation in Electrical Engineering" held in Graz, Austria with the paper "Frequency Dependent Resistance Calculation of Multiple Conductors" written by dr.sc.Tomislav Župan and doc.dr.sc. Bojan Trkulja. The paper presents a numerical method based on integral equations approach useful for calculating multiple conductors’ resistance, taking into account both skin- and proximity-effect.

Author: Tomislav Župan
EMF 2016 in Lyon

The paper entitled "Calculation of Power Frequency Electric Field with Boundary Element Methods and Adaptive Cross Approximation" by Bojan Trkulja and Ana Drandić was presented at the 10th International Symposium on ELECTRIC AND MAGNETIC FIELDS in Lyon.

Author: Bojan Trkulja

Zavod za osnove elektrotehnike i električka mjerenja, Hrvatska sekcija IEEE, Odjel za industrijske primjene i Odjel za elektroenergetiku pozivaju vas na predavanje:

"Moderne numeričke metode za simulaciju elektromagnetskih polja"

koje će održati profesor Jasmin Smajić, ETH Zurich i HSR Rapperswill. Predavanje će se održati u ponedjeljak, 13. lipnja 2016. godine, u 11.00 sati, u dvorani TCR-aFakulteta elektrotehnike i računarstva.

Više o predavaču i predavanju pročitajte u nastavku obavijesti.


Tema predavanja

Proračuni u elektromagnetizmu uključuju složena međudjelovanja električnih, magnetskih i termodinamičkih karakteristika materijala, sustava i okoline. Multidisciplinarni pristup u opisivanju i modeliranju ovih međudjelovanja otvara vrata novim, revolucionarnim mogućnostima u dizajniranju i optimiranju sustava. Predavanjem će se približiti ovo područje kroz sljedeće cjeline:

  1. predstavljanje numeričkih metoda i formulacija elektromagnetskih polja razvijene od strane autora u proteklih 15-ak godina,
  2. demonstracija korištenja prezentiranih metoda u svakodnevnom razvoju novih tehnologija i proizvoda u području visokofrekventnog i niskofrekventnog elektromagnetizma,
  3. pokazati najzanimljivije ideje i praktična rješenja dobivena isključivo simulacijskim putem.

U okviru ove prezentacije moderni numerički postupci i metode konačnih elemenata (FEM), metode rubnih elemenata (BEM), multipolne metode (MMP), svezane FEM-MMP metode i diskontinuirane Galerkin metode (DGFEM) bit će detaljno prikazane s posebnim fokusom na praktične primjene u području vrtložnih struja i elektromagnetskih valova.

Predviđeno trajanje je 90 minuta uz pauzu za kavu oko sredine predavanja.

 

O predavaču

Autor predavanja, prof. Jasmin Smajić je nakon završenog doktorata na Sveučilištu u Zagrebu 2001. godine do danas proveo radeći na Sveučilištu ETH u Zurichu, u Švicarskoj, u ABB-ovom institutu u Badenu i na Sveučilištu HSR u Rapperswilu.

Od 2011. godine u zvanju redovnog profesora predaje na HSR i ETH elektromagnetska polja i numeričke postupke za njihovu simulaciju.

 

Author: Bojan Trkulja

Collaboration with Končar-Instrument transformers Inc. resulted in acquiring two custom-made instrument transformers! One of them has a number of taps along the coil which will greatly help us verify the numerical models used in modelling the high frequency phenomena inside the transformer coils.

Hopefully this is the beginning of a great and productive collaboration!

 

 

Author: Tomislav Župan

Bsc FHO Roman Obrist spent this spring semester as a part of our group! He was a part of the student exchange program resulting from the bilateral agreement under the Swiss-European Mobility Programme.

Roman was mainly working on neural networks models for the average oil rise in power transformers.

Author: Tomislav Župan
Duke University experience

Dipl. Ing. Tomislav Župan spent the 2014/2015 academic year at Duke University as a part of his Fulbright Scholarship. He conducted research in Prof. David R. Smith's group in the fields of:

  • Wireless power transfer in radiative near field,
  • Circularly polarized focusing antennas,
  • Leaky wave antenna design,
  • Novel metamaterial structures.
Author: Tomislav Župan
COMPUMAG 2015 conference in Montreal

The collaboration between our group, HSR Rapperswil and ABB resulted in new frequency domain method for transient analysis of transformer coils presented at COMPUMAG 2015 in Montreal, Canada. The title of the paper is "Transformer Windings’ RLC Parameters Calculation and Lightning Impulse Voltage Distribution Simulation".

Author: Tomislav Župan

PhD student position is available on the HRZZ project "Numerical Modelling of Complex Electromagnetic Phenomena in Transformers" for a period of 4 years.

At this moment, the group is looking for motivated Ph.D. students interested in performing state-of-the-art research in numerical electromagnetism. The group is closely collaborating with Končar in the development of advanced numerical models of complex phenomena in transformers.

We are looking for candidates with the following profile:
A) Master Degree in Electrical Engineering
B) Strong interest in Electromagnetics and Numerical Modelling

We are offering:
A) Fully paid PhD research positions for four years
B) Enthusiastic research team
C) A stimulating environment with lots of opportunities to expand your knowledge

Candidates may send their CVs to bojan.trkulja@fer.hr

Author: Bojan Trkulja

Tomislav Župan won the Fulbright Fellowship and is conducting research in David R.Smith group at Duke University, USA.

Author: Bojan Trkulja
Succesfull organization of 3rd...

The  3rd International Colloquium "Transformer Research and Asset Management" was succesfully organized in Split. Tutorials „Resonance and Feroresonance in Power Network“ by Dr. Zia Emin, Chief Power Systems Engineer, Parsons Brinckerhoff and „Transformer Procurement Process“ by Tom Breckenridge, Technical Director, TB TCS Ltd were held, together with about 50 papers presented by authors.

Details about colloquium together with photos can be found here.

Author: Bojan Trkulja
New HRZZ project

The four-year project "Numerical Modelling of Complex Electromagnetic Phenomena in Transformers" financed by Croatian Science Foundation is approved to prof.dr.sc. Željko Štih.

Author: Bojan Trkulja
3rd International Colloquium...

Faculty of Electrical Engineering and Computing in Zagreb and the Centre of Excellence for Transformers in Zagreb are organizing 3rd International Colloquium “Transformer Research and Asset Management”: in Split, Grand hotel Lav Le Meridien, 15.-17.10.2014.

More information can be found here.

Author: Bojan Trkulja

 Prof. Sead Berberović and prof Željko Štih presented the paper "Analysis of Human Exposure due to Wireless Power Transfer in 100-200 kHz Range". The analysis of human exposure to incident electromagnetic fields generated by wireless power transfer in cars is presented in the paper. 

Author: Bojan Trkulja

Dipl. ing. Tomislav Župan and doc.dr.sc. Bojan Trkulja attended the COMPUMAG 2013 conference with the paper "Fast and Robust Method for Mutual Inductance Calculation of Coaxial Circular Coils with Rectangular Cross Section". The paper presents new and extremely fast and precise method for calculating mutual inductance between coaxial circular coils with rectangular cross section in air.

 

Author: Bojan Trkulja

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