TY - JOUR AU - Koller, László AU - Novák, Balázs TI - Improving the energy efficiency of induction cooking 2 JF - ELECTRICAL ENGINEERING J2 - ELECTR ENG VL - 99 PY - 2017 IS - 1 SP - 171 EP - 178 PG - 8 SN - 0948-7921 DO - 10.1007/s00202-016-0405-2 UR - https://m2.mtmt.hu/api/publication/3126420 ID - 3126420 LA - English DB - MTMT ER - TY - CHAP AU - Novák, Balázs AU - Koller, László ED - IEEE, null TI - Current Distribution and Losses of Grouped Underground Cables T2 - 2012 IEEE PES TRANSMISSION AND DISTRIBUTION CONFERENCE AND EXPOSITION (T&D) PB - IEEE CY - New York, New York SN - 9781467319331 PY - 2012 PG - 1 UR - https://m2.mtmt.hu/api/publication/2686232 ID - 2686232 N1 - Transactions paper AB - To fulfill installation requirements, sometimes, two or more cables have to be connected in parallel in a threephase power distribution system. The division of the current and power among the adjacent cables is governed by several factors, such as position, phase order, and the grounding method of the metal screen. This study demonstrates this effect and compares three solution methods of grouped single-core underground cables with their screens bonded at both the ends. These three methods are: an analytical one provided by international standards and two 2D finite element approaches. One of the FE methods takes the wists of the wire screens into account. LA - English DB - MTMT ER - TY - CHAP AU - Novák, Balázs AU - Koller, László ED - IEEE, null TI - Steady-state Heating of Gas Insulated Busbars T2 - 2012 IEEE PES TRANSMISSION AND DISTRIBUTION CONFERENCE AND EXPOSITION (T&D) PB - IEEE CY - New York, New York SN - 9781467319331 PY - 2012 SP - 1 EP - 7 PG - 7 UR - https://m2.mtmt.hu/api/publication/2686231 ID - 2686231 AB - The alternating current flowing in the busbars of gas insulated switchgears (GIS) or substations generates Joule-heat both in the busbars and – due to eddy currents – in the metal enclosure. Besides heat conduction, the steady-state temperature of the conducting parts highly depends on the heat transfer between them and the encompassing gas insulation. The flow of the gas inside and outside the equipment that is, natural convection together with radiation determines the transferred heat. Such conjugate heat transfer problems can be treated numerically by finite element simulations. This paper compares the results of uni- and bidirectional coupling of electromagnetic and flow field simulations of a high voltage, gas insulated, three-phase busbar. It also discusses the influence of radiation on the results. LA - English DB - MTMT ER - TY - CHAP AU - Novák, Balázs AU - Koller, László ED - anon, null TI - Influence of Phase Order on Losses and Outer Magnetic Field of Grouped Underground Cables T2 - 2011 IEEE PES Power Systems Conference & Exposition PB - IEEE CY - Phoenix (AZ) SN - 9781612847870 PY - 2011 SP - 1 EP - 6 PG - 6 DO - 10.1109/PSCE.2011.5772459 UR - https://m2.mtmt.hu/api/publication/2662561 ID - 2662561 AB - To fulfill installation requirements, sometimes, two or more cables have to be connected in parallel in a three-phase power distribution system. The division of the current among the adjacent cables is governed by several factors, such as position, phase order, and the grounding method of the metal screen. Dissimilar current distributions result in dissimilar power and magnetic-field distributions. Consequently, a modified phase order can alter the total losses and the magnetic induction above the ground. This study demonstrates this effect by finite element simulations of grouped single-core underground cables buried in flat formation, and with screens bonded and grounded at both the ends. LA - English DB - MTMT ER - TY - JOUR AU - Novák, Balázs AU - Koller, László TI - Energiaátviteli Kábelek Huzal-koszorú Árnyékolásának Végeselemes Modellezése JF - ELEKTROTECHNIKA J2 - ELEKTROTECHNIKA VL - 104 PY - 2011 IS - 2 SP - 5 EP - 8 PG - 4 SN - 0367-0708 UR - https://m2.mtmt.hu/api/publication/2653710 ID - 2653710 AB - A cikk huzalkoszorú árnyékolású, egyerű kábelekből álló háromfázisú, többrendszerű kábelvonalak árameloszlásának és veszteségeinek számításával foglalkozik. A vizsgált huzalkoszorú árnyékolás mindkét végén rövidre zárt és földelt. A nemzetközi szabvány analitikus számítási módszerét hasonlítja össze végeselemes szimulációk eredményeivel. Az összehasonlítás két eltérő 2D végeselemes modell eredményeire épül: az egyik a huzalkoszorút párhuzamos vezetőkkel modellezi, míg a másik az árnyékolóhuzalok sodrását is figyelembe veszi. LA - Hungarian DB - MTMT ER - TY - JOUR AU - Novák, Balázs AU - Koller, László TI - Current distribution and losses of grouped underground cables JF - IEEE TRANSACTIONS ON POWER DELIVERY J2 - IEEE T POWER DELIVER VL - 26 PY - 2011 IS - 3 SP - 1514 EP - 1521 PG - 8 SN - 0885-8977 DO - 10.1109/TPWRD.2011.2104980 UR - https://m2.mtmt.hu/api/publication/2385887 ID - 2385887 LA - English DB - MTMT ER - TY - CHAP AU - Balázs, Novák AU - Koller, László ED - IEEE, null TI - Influence of phase order on losses and outer magnetic field of grouped underground cables T2 - Power Systems Conference and Exposition PB - Institute of Electrical and Electronics Engineers (IEEE) CY - Piscataway (NJ) SN - 1612847897 PY - 2011 SP - 210 EP - 215 PG - 6 UR - https://m2.mtmt.hu/api/publication/2385866 ID - 2385866 N1 - Dept. of Electr. Power Eng., Budapest Univ. of Technol. & Econ., Budapest, Hungary LA - English DB - MTMT ER - TY - CHAP AU - Novák, Balázs AU - Tamus, Zoltán Ádám AU - Koller, László ED - IEEE, null TI - Heating of Cables Due to Fault Currents T2 - Conference Record of the 2010 IEEE International Symposium on Electrical Insulation (ISEI 2010) PB - Institute of Electrical and Electronics Engineers (IEEE) CY - Piscataway (NJ) SN - 1424462983 PY - 2010 SP - 1 EP - 5 PG - 5 DO - 10.1109/ELINSL.2010.5549812 UR - https://m2.mtmt.hu/api/publication/2653973 ID - 2653973 N1 - AB - The metal screening of new type of medium and high voltage single-core underground cables is comprised of helically applied copper wires embedded in a semiconductive layer. The distribution of current and power among the thin wires is non-uniform in a three-phase system, what can lead to their non-uniform heating, especially during fault conditions. The paper investigates this problem with 2D finite element models. The simulations are based on the coupling of the electromagnetic and thermal fields. LA - English DB - MTMT ER - TY - CHAP AU - Novák, Balázs AU - Koller, László AU - Berta, István ED - ICREPQ, null TI - Loss reduction in cable sheathing T2 - International Conference on Renewable Energies and Power Quality (ICREPQ'10) PB - University of Granada CY - Granada SN - 9788461375431 PY - 2010 SP - 1 EP - 5 PG - 5 UR - https://m2.mtmt.hu/api/publication/2653651 ID - 2653651 AB - In order to reduce electric potential difference between the sheathings of single core three-phase cables, the sheathing is grounded and bonded at one or both ends of the cables. If the cable is long, double bonding has to be carried out which leads to circulating currents and increased power loss. Based on finite element (FE) calculations, this paper shows, that raising the sheath’s resistance, by decreasing its cross section and increasing its resistivity, can significantly reduce this loss. The magnetic field close to the ground surface and the behaviour of the cable during fault conditions are also investigated. LA - English DB - MTMT ER - TY - JOUR AU - Koller, László AU - Novák, Balázs TI - Újfajta edény indukciós főzéshez JF - ELEKTROTECHNIKA J2 - ELEKTROTECHNIKA VL - 103 PY - 2010 IS - 2 SP - 5 EP - 8 PG - 4 SN - 0367-0708 UR - https://m2.mtmt.hu/api/publication/2652559 ID - 2652559 AB - A kezdeti nehézségek után, az árak csökkenésének köszönhetően, az utóbbi években már a háztartások számára is egyre inkább elérhetővé váltak az indukciós főzőlapok. Cikkünkben bemutatjuk, hogy egy újfajta edény használatával az eddigieknél még kényelmesebb, dinamikusabb és energiatakarékosabb főzés valósítható meg. LA - Hungarian DB - MTMT ER -