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Majid, Abdul
Publications (10 of 14) Show all publications
Saleem, J., Majid, A., Bertilsson, K. & Carlberg, T. (2013). 3 Dimensional Finite Element Simulation of Seam Welding Process. Paper presented at 17th International Conference ELECTRONICS 2013 Palanga, Lithuania. Elektronika Ir Elektrotechnika, 19(8), 73-78
Open this publication in new window or tab >>3 Dimensional Finite Element Simulation of Seam Welding Process
2013 (English)In: Elektronika Ir Elektrotechnika, ISSN 1392-1215, Vol. 19, no 8, p. 73-78Article in journal (Refereed) Published
Abstract [en]

The versatility, rich mathematical formulations and robustness of finite element methods make them attractive for simulations for a wide range of problems. Two dimensional models concerning the seam welding process do have some limitations. The longitudinal two dimensional models cannot be used to examine the effects of the electrode shape and thickness regarding heat generation during the seam welding process. The transversal two dimensional models are not helpful for examining the nugget growth during the seam welding process. The heat energy generated during the seam welding process mainly depends on the resistance between the electrodes, welding current, rotational speed and the geometry of the electrodes. The settings for appropriate parameters in relation to a seam welding machine, with regards to sheets of different thicknesses, depends on trial and error methods. These methods are expensive and time consuming. The three dimensional model developed in this paper is a step towards selecting the appropriate welding parameters so as to produce a good welding nugget. 

Keywords
Seam welding, Finite element method, Temperature dependent material properties, Heat affected zone, Weld nugget formation, Inverter drive resistance welding equipment
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-19736 (URN)10.5755/j01.eee.19.8.5398 (DOI)000325684100016 ()2-s2.0-84885653756 (Scopus ID)STC (Local ID)STC (Archive number)STC (OAI)
Conference
17th International Conference ELECTRONICS 2013 Palanga, Lithuania
Projects
Electronics
Available from: 2013-08-19 Created: 2013-08-19 Last updated: 2016-10-20Bibliographically approved
Saleem, J., Majid, A., Haller, S. & Bertilsson, K. (2013). A study of IGBT rupture phenomenon in medium frequency resistance welding machine. In: Electrical Machines and Power Electronics and 2011 Electromotion Joint Conference (ACEMP), 2011 International Aegean Conference on: . Paper presented at Acemp - electromotion 2011, 8-10 September 2011 Istanbul - Turkey (pp. 236-239). IEEE conference proceedings
Open this publication in new window or tab >>A study of IGBT rupture phenomenon in medium frequency resistance welding machine
2013 (English)In: Electrical Machines and Power Electronics and 2011 Electromotion Joint Conference (ACEMP), 2011 International Aegean Conference on, IEEE conference proceedings, 2013, p. 236-239Conference paper, Published paper (Refereed)
Abstract [en]

Inverter drive resistance spot welding machines are becoming a good choice of welding because of the increased machine efficiency and output power. The DC link capacitors in spot welding equipment store a large amount of energy. In case of any failure, the IGBT in the inverter has a risk of exhibiting a violent rupture. This rupture can damage the converter, drive down time and personal injury which may lead to the machinery certification problems. IGBT failure detection and solution for protection of these failures in resistance welding machines have not been reported in literature. Literature study of the IGBT failure, rupture, fault detection and protection has been carried out for inverter drives in power applications. On the basis of the findings some protection schemes and important measures in the design of the machine have been adopted which have resulted in the reduced risk of IGBT failure.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2013
Keywords
Resistance welding; IGBT rupture; Inverter drive; Medium frequency spot welding machines
National Category
Engineering and Technology
Identifiers
urn:nbn:se:miun:diva-14565 (URN)10.1109/ACEMP.2011.6490602 (DOI)2-s2.0-84876460443 (Scopus ID)STC (Local ID)978-1-4673-5002-0 (ISBN)STC (Archive number)STC (OAI)
Conference
Acemp - electromotion 2011, 8-10 September 2011 Istanbul - Turkey
Available from: 2011-10-04 Created: 2011-10-04 Last updated: 2017-11-02Bibliographically approved
Majid, A. (2013). Analysis and EMI suppression of MHz frequency range switch mode power supplies. (Doctoral dissertation). Sundsvall: Mid Sweden University
Open this publication in new window or tab >>Analysis and EMI suppression of MHz frequency range switch mode power supplies
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University, 2013. p. 139
Series
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 164
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-21019 (URN)STC (Local ID)978-91-87557-08-8 (ISBN)STC (Archive number)STC (OAI)
Supervisors
Available from: 2014-01-13 Created: 2014-01-13 Last updated: 2016-10-20Bibliographically approved
Majid, A., Saleem, J., Kotte, H. B., Ambatipudi, R., Haller, S. & Bertilsson, K. (2013). Analysis of feedback in converter using coreless printed circuit board transformer. In: Electrical Machines and Power Electronics and 2011 Electromotion Joint Conference (ACEMP), 2011 International Aegean Conference on: . Paper presented at International Aegean Conference on Electric Machines and Power Electronics & Electromotion Joint Conference 08-10 September 2011 İstanbul, Turkey (pp. 601-604). IEEE conference proceedings
Open this publication in new window or tab >>Analysis of feedback in converter using coreless printed circuit board transformer
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2013 (English)In: Electrical Machines and Power Electronics and 2011 Electromotion Joint Conference (ACEMP), 2011 International Aegean Conference on, IEEE conference proceedings, 2013, p. 601-604Conference paper, Published paper (Refereed)
Abstract [en]

Power supply is an inevitable component for all electronic instruments as a constant DC source. Almost all power supplies use feedback loop to achieve constant DC output voltage. In a feedback loop, the galvanic isolation is required between input and output. It can be achieved either by implementation of opto-coupler feedback on the secondary side or magnetic feedback. In this paper both opto-coupler and auxiliary feed-back techniques are implemented and analyzed in a high frequency half bridge converter using coreless Printed Circuit Board (PCB) power transformer. The implementation of opto-coupler feedback is temperature sensitive and has relatively high cost. The auxiliary winding of transformer can also be used to provide feedback signals as alternate to opto-coupler. Auxiliary feedback implementation is cheaper, temperature stable and insensitive to temperature variations. In this paper, the feasibility of feedback using auxiliary winding of coreless PCB power transformer is investigated. It is observed that this technique can be used as an alternative to opto-coupler feedback.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2013
Keywords
Analog to digital conversion; Electro-magnetic interference; Switch mode power supplies; Printed circuit board; Pulse width modulation
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-14523 (URN)10.1109/ACEMP.2011.6490667 (DOI)2-s2.0-84876496931 (Scopus ID)STC (Local ID)978-1-4673-5002-0 (ISBN)STC (Archive number)STC (OAI)
Conference
International Aegean Conference on Electric Machines and Power Electronics & Electromotion Joint Conference 08-10 September 2011 İstanbul, Turkey
Available from: 2011-09-21 Created: 2011-09-22 Last updated: 2017-11-02Bibliographically approved
Majid, A., Saleem, J., Alam, F. & Bertilsson, K. (2013). Analysis of radiated EMI for power converters switching in MHz frequency range. In: Proceedings - 2013 9th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, SDEMPED 2013: . Paper presented at 2013 9th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, SDEMPED 2013; Valencia; Spain; 27 August 2013 through 30 August 2013; Category number CFP13SDE-ART; Code 101470 (pp. 428-432). IEEE conference proceedings
Open this publication in new window or tab >>Analysis of radiated EMI for power converters switching in MHz frequency range
2013 (English)In: Proceedings - 2013 9th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, SDEMPED 2013, IEEE conference proceedings, 2013, p. 428-432Conference paper, Published paper (Refereed)
Abstract [en]

The higher switching frequency in combination with di/dt loops and dv/dt nodes in the power stages of high frequency power converters generates higher order harmonics which cause Electro Magnetic Interference (EMI). It is commonly perceived that high frequency converters are more vulnerable to radiated EMI, thus, it is very important to analyze the radiated emission of these converters. According to the author’s knowledge, the analysis of the radiated emission of power converters switching in the MHz frequency region has not been presented until now. Therefore, in this paper, the measurements, and analysis of the near field radiated emissions of these emerging power converters is presented. These measurements are beneficial in the early design stage of power converters. Both E-field and H-field and captured and analyzed for a half bridge converter switching at 3 MHz and at the output power level of 25 W. The effects of the magnetic and electric field emissions with the addition of a Y-capacitor and secondary side common mode choke are analyzed.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2013
Keywords
bridge circuits;capacitors;electromagnetic interference;harmonics;switching convertors;E-field;EMI radiation;H-field;electromagnetic interference;frequency 3 MHz;half bridge converter switching;high frequency power converter generation;higher order harmonics;near field radiated emissions;power 25 W;power converter switching;power stages;switching frequency;Electromagnetic interference;Frequency conversion;Frequency measurement;Harmonic analysis;Inductors;Magnetic field measurement;Probes;Common Mode;Differential Mode;Electro Magnetic Compatibility;Electro Magnetic Interference
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-21017 (URN)10.1109/DEMPED.2013.6645751 (DOI)2-s2.0-84891097524 (Scopus ID)STC (Local ID)978 - 1 - 4799 - 002 5 - 1 (ISBN)STC (Archive number)STC (OAI)
Conference
2013 9th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, SDEMPED 2013; Valencia; Spain; 27 August 2013 through 30 August 2013; Category number CFP13SDE-ART; Code 101470
Available from: 2014-01-13 Created: 2014-01-13 Last updated: 2016-10-20Bibliographically approved
Majid, A., Saleem, J., Alam, F. & Bertilsson, K. (2013). EMI Suppression in High Frequency Half Bridge Converter. Paper presented at 17th International Conference 2013 Palanga. Elektronika ir Elektrotechnika, 19(9), 75-80
Open this publication in new window or tab >>EMI Suppression in High Frequency Half Bridge Converter
2013 (English)In: Elektronika ir Elektrotechnika, ISSN 1392-1215, Vol. 19, no 9, p. 75-80Article in journal (Refereed) Published
Abstract [en]

Electromagnetic effects influence the design of power converters switching in MHz frequency region. In these converters, the high switching frequency in combination with sudden changes in current and voltage levels generate higher order harmonics which causes Electro Magnetic Interference (EMI). To study the effects of increased switching frequency on conducted EMI, the harmonics amplitudes are analyzed by increasing the switching frequency of a two wire input half bridge power converter from 1.32 MHz to 3 MHz. In order to suppress the Common Mode (CM) conducted EMI, different possibilities of connecting the Y- capacitor in a two wire universal input half bridge converter are discussed and the conducted EMI is measured and analyzed by connecting the Y- capacitor at different points. The line filters are designed, characterized and implemented in order to suppress conducted EMI. The effects of increased switching frequency on the line filter design are studied by analysing the EMI spectrum of both the converters. The analysis of results indicates that the filter size is reduced by increasing the switching frequency of the power converter. 

Place, publisher, year, edition, pages
Kauno Technologijos Universitetas Lithuania: , 2013
Keywords
Common Mode, Differential Mode, Electro Magnetic Interference, Electro Magnetic Compatibility, Line Impedance Stabilization Network
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-19737 (URN)10.5755/j01.eee.19.9.5653 (DOI)000330687100016 ()2-s2.0-84887494301 (Scopus ID)STC (Local ID)STC (Archive number)STC (OAI)
Conference
17th International Conference 2013 Palanga
Note

Title registered incorrectly in Scopus: EMT suppression in high frequency half bridge converter

Available from: 2013-08-19 Created: 2013-08-19 Last updated: 2016-10-20Bibliographically approved
Majid, A. (2012). Analysis and implementation of switch mode power supplies in MHz frequency region. (Licentiate dissertation). Sundsvall: Mid Sweden University
Open this publication in new window or tab >>Analysis and implementation of switch mode power supplies in MHz frequency region
2012 (English)Licentiate thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University, 2012. p. 56
Series
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 80
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-16691 (URN)STC (Local ID)978-91-87103-13-1 (ISBN)STC (Archive number)STC (OAI)
Available from: 2012-08-08 Created: 2012-08-08 Last updated: 2016-10-20Bibliographically approved
Majid, A., Saleem, J., Kotte, H. B., Ambatipudi, R. & Bertilsson, K. (2012). Design and implementation of EMI filter for high frequency (MHz) power converters. In: IEEE International Symposium on Electromagnetic Compatibility: . Paper presented at International Symposium on Electromagnetic Compatibility, EMC EUROPE 2012;Rome;17 September 2012through21 September 2012;Code95036 (pp. Art. no. 6396738). IEEE conference proceedings
Open this publication in new window or tab >>Design and implementation of EMI filter for high frequency (MHz) power converters
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2012 (English)In: IEEE International Symposium on Electromagnetic Compatibility, IEEE conference proceedings, 2012, p. Art. no. 6396738-Conference paper, Published paper (Refereed)
Abstract [en]

The fabrication of emerging power semiconductor devices and high frequency PCB power transformers has made it possible to design the power converters in MHz switching frequency range. However, the higher switching frequency, di/dt loops and dv/dt nodes in power stages of these converters generate higher order harmonics which causes Electro Magnetic Interference (EMI). It is commonly believed that the EMI has worst affect in the converters switching in MHz frequency range than the converters operating below 150 kHz. Thus, it is important research direction to investigate the consequences of implementing a line filter to suppress the conducted EMI in high frequency power converters. In this paper, the measurements, and analysis of the conducted EMI in emerging power converters, switching in MHz frequency range, and the design of the filter for its suppression is presented. The design of LISN and its PCB implementation for EMI measurements is presented. The measurement of conducted EMI of a half bridge DC-DC converter switching at          3.45 MHz and the analysis of the frequency spectrum is discussed. The design, PCB implementation and characterization of the EMI filter and the measurement of the suppressed conducted noise by applying the filter are also discussed.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2012
Keywords
Electro Magnetic Compatibility; Electro Magnetic Interference; Line Impedance Stablization Network; Pulse Width Modulation
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-16527 (URN)10.1109/EMCEurope.2012.6396738 (DOI)2-s2.0-84872565389 (Scopus ID)STC (Local ID)STC (Archive number)STC (OAI)
Conference
International Symposium on Electromagnetic Compatibility, EMC EUROPE 2012;Rome;17 September 2012through21 September 2012;Code95036
Available from: 2012-10-01 Created: 2012-06-21 Last updated: 2016-10-20Bibliographically approved
Majid, A., Saleem, J. & Bertilsson, K. (2012). EMI filter design for high frequency power converters. In: 2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012: Conference Proceedings. Paper presented at 2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012;Venice;18 May 2012through25 May 2012;Category numberCFP1251I-CDR;Code91459 (pp. 586-589). IEEE conference proceedings
Open this publication in new window or tab >>EMI filter design for high frequency power converters
2012 (English)In: 2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012: Conference Proceedings, IEEE conference proceedings, 2012, p. 586-589Conference paper, Oral presentation only (Refereed)
Abstract [en]

With the emerging power semiconductor devices in GaN and SiC technology and the development of high frequency multilayered PCB power transformers, power efficient DC-DC converters are designed in megahertz switching frequency range. The increased switching frequency in combination with sudden changes in current “di/dt” or voltage “dv/dt” levels generate higher order harmonics, which cause Electro Magnetic Interference (EMI). One of the major challenges, to design the power stage of these converters, is to minimize the EMI because it affects their Electro Magnetic Compatibility (EMC). There is a spread belief that the EMI becomes much worse in a MHz switching converter compared to the current ones operating below 150 kHz. This paper investigates the consequences on implementation of a line filter for suppressing conducted EMI in high frequency power converters. The results are based on electronic simulations, comparing EMI and filter design, for a 200 kHz and 2 MHz buck converter under similar conditions. By analyzing the noise frequency spectrum of both the converters it is observed that the size of filter components, such as capacitors and common mode chokes is greatly reduced in case of 2MHz Buck converter. The results show that the size reduction that can be accomplished by increasing the switching frequency to MHz range can be improved further by a smaller implementation of the line filter as well.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2012
Keywords
Electro Magnetic Interference, Electro Magnetic Compatibility, Line Impedance Stablizer Network, Pulse With
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-16524 (URN)10.1109/EEEIC.2012.6221444 (DOI)2-s2.0-84864246773 (Scopus ID)STC (Local ID)978-1-4577-1830-4 (ISBN)STC (Archive number)STC (OAI)
Conference
2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012;Venice;18 May 2012through25 May 2012;Category numberCFP1251I-CDR;Code91459
Available from: 2012-09-05 Created: 2012-06-21 Last updated: 2016-10-20Bibliographically approved
Saleem, J., Majid, A., Bertilsson, K., Carlberg, T. & Nazar Ul Islam, M. (2012). Nugget Formation During Resistance Spot Welding Using Finite Element Model. Paper presented at International Conference on Aerospace, Mechanical, Automotive and Materials Engineering. World Academy of Science, Engineering and Technology: An International Journal of Science, Engineering and Technology, 67
Open this publication in new window or tab >>Nugget Formation During Resistance Spot Welding Using Finite Element Model
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2012 (English)In: World Academy of Science, Engineering and Technology: An International Journal of Science, Engineering and Technology, ISSN 2010-376X, E-ISSN 2070-3740, Vol. 67Article in journal (Refereed) Published
Abstract [en]

Resistance spot welding process comprises of electric, thermal and mechanical phenomenon, which makes this process complex and highly non-linear and thus, it becomes difficult to model it. In order to obtain good weld nugget during spot welding, hit and trial welds are usually done which is very costly. Therefore the numerical simulation research has been conducted to understand the whole process. In this paper three different cases were analyzed by varying the tip contact area and it was observed that, with the variation of tip contact area the nugget formation at the faying surface is affected. The tip contact area of the welding electrode becomes large with long welding cycles. Therefore in order to maintain consistency of nugget formation during the welding process, the current compensation in control feedback is required. If the contact area of the welding electrode tip is reduced, a large amount of current flows through the faying surface, as a result of which sputtering occurs.

Keywords
Resistance spot welding, Finite element modeling, Nugget formation, Welding electrode, Numerical method simulation
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-16528 (URN)STC (Local ID)STC (Archive number)STC (OAI)
Conference
International Conference on Aerospace, Mechanical, Automotive and Materials Engineering
Available from: 2012-09-03 Created: 2012-06-21 Last updated: 2017-12-07Bibliographically approved
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