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Samadaei, E., Kaviani, M. & Bertilsson, K. (2019). A 13-levels Module (K-Type) with two DC sources for Multilevel Inverters. IEEE transactions on industrial electronics (1982. Print), 66(7), 5186-5196
Open this publication in new window or tab >>A 13-levels Module (K-Type) with two DC sources for Multilevel Inverters
2019 (English)In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 66, no 7, p. 5186-5196Article in journal (Refereed) Published
Abstract [en]

This paper presents a new reconfiguration module for asymmetrical multilevel inverters in which the capacitors are used as the DC links to creates the levels for staircase waveforms. This configuration of multilevel converter makes a reduction in DC sources. On the other hand, it is possible to generate 13 levels with lower DC sources. The proposed module of multilevel inverter generates 13 levels with two unequal DC sources (2VDC and 1VDC). It also involves two chargeable capacitors and 14 semiconductor switches. The capacitors are self-charging without any extra circuit. The lower number of components makes it desirable to use in wide range of applications. The module is schematized as two back-to-back T-type inverters and some other switches around it. Also, it can be connected as cascade modular which lead to a modular topology with more voltage levels at higher voltages. The proposed module makes the inherent creation of the negative voltage levels without any additional circuit (such as H-bridge circuit). Nearest level control switching modulation (NLC) scheme is applied to achieve high quality sinusoidal output voltage. Simulations are executed in MATLAB/Simulink and a prototype is implemented in the power electronics laboratory which the simulation and experimental results show a good performance.

Keywords
Asymmetric, capacitors, multilevel inverter, nearest level control switching, power electronics, self-charging
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-34710 (URN)10.1109/TIE.2018.2868325 (DOI)000460663300021 ()2-s2.0-85053154849 (Scopus ID)
Available from: 2018-10-12 Created: 2018-10-12 Last updated: 2019-10-16Bibliographically approved
Vijeh, M., Rezanejad, M., Samadaei, E. & Bertilsson, K. (2019). A General Review of Multilevel Inverters Based on Main Submodules: Structural Point of View. IEEE transactions on power electronics, 34(10), 9479-9502
Open this publication in new window or tab >>A General Review of Multilevel Inverters Based on Main Submodules: Structural Point of View
2019 (English)In: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 34, no 10, p. 9479-9502Article in journal (Refereed) Published
Abstract [en]

Multilevel inverters (MLIs) are being used in wide range of power electronics applications. These converters that are attracted a lot of attentions during recent years have different topologies with similar basic concept. This paper presents five main submodules (SMs) that are used as the basic structures of MLIs. The paper reviews the common multilevel inverter topologies with the structural point of view. The topologies are divided to main SMs to show conventional MLIs configuration and future topologies that can be created from the main SMs. The comparative study on topologies is investigated with details. The MLIs are categorized and investigated with due attention to some indexes such as the number of components, the ability to create inherent negative voltage, working in regeneration mode and using single DC source.

Keywords
Asymmetric, multilevel inverter (MLI), power electronics, symmetric
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-35505 (URN)10.1109/TPEL.2018.2890649 (DOI)000474581900014 ()2-s2.0-85063804140 (Scopus ID)
Available from: 2019-01-23 Created: 2019-01-23 Last updated: 2019-10-16Bibliographically approved
Alishah, R. S., Hasani, M. Y., Hosseini, S. H., Bertilsson, K. & Babalou, M. (2019). Analysis and Design of a New Extendable Sepic Converter with High Voltage Gain and Reduced Components for Photovoltaic Applications. In: 2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC): . Paper presented at 10th Annual International Power Electronics, Drive Systems and Technologies Conference (PEDSTC2019) (pp. 492-497). IEEE, Article ID 8697249.
Open this publication in new window or tab >>Analysis and Design of a New Extendable Sepic Converter with High Voltage Gain and Reduced Components for Photovoltaic Applications
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2019 (English)In: 2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC), IEEE, 2019, p. 492-497, article id 8697249Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a high step-up DC-DC converter which is appropriate for Photovoltaic systems. This topology has been combined from an extended switched-capacitor and a common SEPIC converter. Low components and high-voltage-gain are the main benefits of the introduced topology. Low rate current ripple, easy control and continuous input current are other advantages of the presented structure. Integrating the switched-capacitor with the SEPIC converter leads to increase the output voltage with variable conversion ratio which can be used for a wide range of loads. The switched-capacitor converter provides a constant dc output voltage while the SEPIC converter extracts maximum power of PV panels because it operates under control of duty cycle. Continuous input current is highly suitable for PV applications. The operating principles and steady-state analysis of the suggested topology are discussed in detail. In order to assess the effectiveness of the presented topology, it has been simulated on PSCAD/EMTDC software.

Place, publisher, year, edition, pages
IEEE, 2019
Keywords
SEPIC converter, Switched-capacitor, High dc output voltage, Photovoltaic applications
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-35503 (URN)10.1109/PEDSTC.2019.8697249 (DOI)000469800900085 ()2-s2.0-85065477474 (Scopus ID)978-1-5386-9254-7 (ISBN)
Conference
10th Annual International Power Electronics, Drive Systems and Technologies Conference (PEDSTC2019)
Available from: 2019-01-23 Created: 2019-01-23 Last updated: 2019-07-09Bibliographically approved
Akram, S., Alam, F. M., Bertilsson, K. & Sidén, J. (2019). Capacitive and optical sensing for automatic detection and characterization of cleaning sponges in fiber optic microduct installations. In: Proceedings - 2019 8th International Workshop on Advances in Sensors and Interfaces, IWASI 2019: . Paper presented at 8th International Workshop on Advances in Sensors and Interfaces, IWASI 2019, Otranto, Italy, 13 June 2019 through 14 June 2019 (pp. 274-278). IEEE, Article ID 8791315.
Open this publication in new window or tab >>Capacitive and optical sensing for automatic detection and characterization of cleaning sponges in fiber optic microduct installations
2019 (English)In: Proceedings - 2019 8th International Workshop on Advances in Sensors and Interfaces, IWASI 2019, IEEE, 2019, p. 274-278, article id 8791315Conference paper, Published paper (Refereed)
Abstract [en]

Optical fiber duct installation requires blowing of cleaning sponges for dirt and moisture removal before blowing the fiber cables. The traditional method requires one operator that blows the sponge and one operator in the receiving end that manually evaluate the sponges until a dry sponge is received. The proposed system eliminates the need of a second operator by introducing a solution for automatic sponge detection and characterization of moisture in sponges at the receiving end. An optical sensor is used for detection and a capacitive sensor is developed to measure the sponge's wetness. Sensor data is automatically transmitted back to the operator at the feeding end via a mobile phone. The system is characterized to work with sponges ranging from saturated with wetness to what is deemed as dry. 

Place, publisher, year, edition, pages
IEEE, 2019
Keywords
Capacitive sensor, Optical fiber cable blowing, Optical Fiber Duct, Optical Sensor
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-37305 (URN)10.1109/IWASI.2019.8791315 (DOI)000502733100062 ()2-s2.0-85071433558 (Scopus ID)978-1-7281-0557-4 (ISBN)
Conference
8th International Workshop on Advances in Sensors and Interfaces, IWASI 2019, Otranto, Italy, 13 June 2019 through 14 June 2019
Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2020-01-16Bibliographically approved
Das, M. & Bertilsson, K. (2019). GaN Based Converters for Battery Charging Application of Electric Vehicle. In: IECON2019: 45th Annual Conference of the IEEE Industrial Electronics Society. Paper presented at IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society. IEEE
Open this publication in new window or tab >>GaN Based Converters for Battery Charging Application of Electric Vehicle
2019 (English)In: IECON2019: 45th Annual Conference of the IEEE Industrial Electronics Society, IEEE, 2019Conference paper, Published paper (Refereed)
Abstract [en]

The high frequency capability and low on-state losses of Gallium Nitride (GaN) transistors offer the potential to increase converter efficiency and/or reduce heatsink and passive component size. This paper investigates the use of GaN technology to enhance the performance of power factor correction (PFC) and LLC converters for battery charging applications. First the efficiency performance of non-isolated PFC converters using GaN transistors is compared by simulation, the asymmetric bridgeless PFC converter is shown to achieve the best efficiency, with a predicted figure of 99% in a 1MHz, 200W design. The predictions are validated by an experimental prototype using a GS66502B, GaN Systems E-mode GaN transistor. Then the efficiency comparison of the PFC and LLC converter using GaN devices for battery charging applications is included in the paper. The experimental results of the PFC converter with GaN devices are also included. Additionally, this paper includes the analysis and design of a common mode input filter for the GaN-based high frequency converters for battery charging application. The size of both the converters using GaN devices is reduced by 40% than the converters based on Si devices. The switching loss comparison of GaN and Si devices are also included in the paper.

Place, publisher, year, edition, pages
IEEE, 2019
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-37563 (URN)10.1109/IECON.2019.8927651 (DOI)978-1-7281-4878-6 (ISBN)
Conference
IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society
Available from: 2019-10-22 Created: 2019-10-22 Last updated: 2019-12-12Bibliographically approved
Akram, S., Bertilsson, K. & Sidén, J. (2019). LTspice electro-thermal model of joule heating in high density polyethylene optical fiber microducts. Electronics (Switzerland), 8(12), Article ID 1453.
Open this publication in new window or tab >>LTspice electro-thermal model of joule heating in high density polyethylene optical fiber microducts
2019 (English)In: Electronics (Switzerland), ISSN 2079-9292, Vol. 8, no 12, article id 1453Article in journal (Refereed) Published
Abstract [en]

At present, optical fiber microducts are joined together by mechanical type joints. Mechanical joints are bulky, require more space in multiple duct installations, and have poor water sealing capability. Optical fiber microducts are made of high-density polyethylene which is considered best for welding by remelting. Mechanical joints can be replaced with welded joints if the outer surface layer of the optical fiber microduct is remelted within one second and without thermal damage to the inner surface of the optical fiber duct. To fulfill these requirements, an electro-thermal model of Joule heat generation using a copper coil and heat propagation inside different layers of optical fiber microducts was developed and validated. The electro-thermal model is based on electro-thermal analogy that uses the electrical equivalent to thermal parameters. Depending upon the geometric shape and material properties of the high-density polyethylene, low-density polyethylene, and copper coil, the thermal resistance and thermal capacitance values were calculated and connected to the Cauer RC-ladder configuration. The power input to Joule heating coil and thermal convection resistance to surrounding air were also calculated and modelled. The calculated thermal model was then simulated in LTspice, and real measurements with 50 µm K-type thermocouples were conducted to check the validity of the model. Due to the non-linear transient thermal behavior of polyethylene and variations in the convection resistance values, the calculated thermal model was then optimized for best curve fitting. Optimizations were conducted for convection resistance and the power input model only. The calculated thermal parameters of the polyethylene layers were kept intact to preserve the thermal model to physical structure relationship. Simulation of the optimized electro-thermal model and actual measurements showed to be in good agreement. 

Keywords
Cauer network, Electro-thermal model, Foster network, High-density polyethylene, RC-ladder, Thermal capacitance, Thermal resistance
Identifiers
urn:nbn:se:miun:diva-38208 (URN)10.3390/electronics8121453 (DOI)000506678200080 ()2-s2.0-85075926885 (Scopus ID)
Available from: 2020-01-10 Created: 2020-01-10 Last updated: 2020-01-31Bibliographically approved
Barg, S., Alam, F. M. & Bertilsson, K. (2019). Modeling of the Geometry Effect on the Core Loss and Verification with a Measurement Technique Based on the Seebeck Effect and FEA. In: IEEE (Ed.), IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society: . Paper presented at IECON 2019 (pp. 1832-1837). IEEE
Open this publication in new window or tab >>Modeling of the Geometry Effect on the Core Loss and Verification with a Measurement Technique Based on the Seebeck Effect and FEA
2019 (English)In: IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society / [ed] IEEE, IEEE, 2019, p. 1832-1837Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, the effect of the core geometry of non-toroidal magnetic cores on the magnetic loss is investigated. A frequency dependent core material-geometry loss factor is developed. This factor is function of the change in the non-toroidal core section and the Steinmetz parameter “β”. In addition, the temperature effect is included in the developed loss model for wide range of frequency and magnetic flux density. The model is applied for ER core and 3C92 ferrite material. The core loss measurements are performed using a Peltier cell. The principle of operation of the Peltier cell is based on the Seebeck effect, which convert the heat flow due to the temperature difference into electric power.  The calibration of the Peltier cell is validated with a resistive load and a relative error lower than 1% is achieved. The accuracy of the developed model is assessed with FEA and the experimental results. A maximum error of 10% is registered of the developed core loss model.

Place, publisher, year, edition, pages
IEEE, 2019
Keywords
core loss, core geometry effect, Peltier cell, Seebeck effect, FEA
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-37591 (URN)10.1109/IECON.2019.8927344 (DOI)978-1-7281-4878-6 (ISBN)
Conference
IECON 2019
Available from: 2019-10-28 Created: 2019-10-28 Last updated: 2019-12-20Bibliographically approved
Barg, S. & Bertilsson, K. (2019). Multi‑objective Pareto and GAs nonlinear optimization approach for fyback transformer. Electrical engineering (Berlin. Print), 101(3), 995-1006
Open this publication in new window or tab >>Multi‑objective Pareto and GAs nonlinear optimization approach for fyback transformer
2019 (English)In: Electrical engineering (Berlin. Print), ISSN 0948-7921, E-ISSN 1432-0487, Vol. 101, no 3, p. 995-1006Article in journal (Refereed) Published
Abstract [en]

Design and optimization of high-frequency inductive components is a complex task because of the huge number of variables to manipulate, the strong interdependence and the interaction between variables, the nonlinear variation of some design variables as well as the problem nonlinearity. This paper proposes a multi-objective design methodology of a 200-W flyback transformer in continuous conduction mode using genetic algorithms and Pareto optimality concept. The objective is to minimize loss, volume and cost of the transformer. Design variables such as the duty cycle, the winding configuration and the core shape, which have great effects on the former objectives but were neglected in previous works, are considered in this paper. The optimization is performed in discrete research space at different switching frequencies. In total, 24 magnetic materials, 6 core shapes and 2 winding configurations are considered in the database. Accurate volume and cost models are also developed to deal with the optimization in the discrete research space. The bi-objective (loss–volume) and tri-objective (loss–volume–cost) optimization results are presented, and the variations of the design variables are analyzed for the case of 60 kHz. An example of a design (30 kHz) is experimentally verified. The registered efficiency is 88% at full load.

Place, publisher, year, edition, pages
Germany: Springer Berlin/Heidelberg, 2019
Keywords
Genetic algorithms, NSGAII, Pareto front, Flyback converter, Transformer, Core loss, Winding loss
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-37384 (URN)10.1007/s00202-019-00836-3 (DOI)000498167600024 ()2-s2.0-85074033042 (Scopus ID)
Projects
WIRIC
Available from: 2019-09-26 Created: 2019-09-26 Last updated: 2020-01-16Bibliographically approved
Bakar, M. A., Alam, F. M., Das, M., Barg, S. & Bertilsson, K. (2019). Reconfigurable three state dc-dc power converter for the wide output range applications. In: IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society: . Paper presented at 45th Proceedings of inductrial electronics, Lisbon, Portugal (pp. 4911-4916). Lisbon: IEEE
Open this publication in new window or tab >>Reconfigurable three state dc-dc power converter for the wide output range applications
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2019 (English)In: IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society, Lisbon: IEEE, 2019, p. 4911-4916Conference paper, Published paper (Refereed)
Abstract [en]

Improving the dc voltage gain of power converters has been the primary focus of the current and past research in the area of power electronics. This work presents another solution to widen the range of the output voltage. It proposes three reconfigurable steps for the output voltage. The range of theoutput voltage varies up to four times the base level. These configurations together vary the output voltage from 15 to 96 volts. A soft switched dc-dc power converter is built with the traditional topology of phase shifted full bridge converter along with improved characteristics. For better management of thetransformer loss, a configuration of four transformers has been employed. The proportional gate drive approach is implemented to obtain four similar isolated blocks of the output voltage. This makes it possible to either configure these blocks all in series,parallel or in series/ parallel combination of two. The concept is verified in a low-profile prototype. The hardware is characterized up to the load power of 1kW for the input voltage of 400Vdc. The converter reports better efficiency over the complete range of output voltage.

Place, publisher, year, edition, pages
Lisbon: IEEE, 2019
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-37646 (URN)10.1109/IECON.2019.8927652 (DOI)978-1-7281-4878-6 (ISBN)
Conference
45th Proceedings of inductrial electronics, Lisbon, Portugal
Available from: 2019-11-08 Created: 2019-11-08 Last updated: 2019-12-20
Bakar, M. A., Alam, F. M. & Bertilsson, K. (2016). A phase shifted full bridge converter with novel control over the leakage inductance. In: 2016 18TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'16 ECCE EUROPE): . Paper presented at 18th European Conference on Power Electronics and Applications (EPE), SEP 05-09, 2016, GERMANY. Institute of Electrical and Electronics Engineers (IEEE), Article ID 7695545.
Open this publication in new window or tab >>A phase shifted full bridge converter with novel control over the leakage inductance
2016 (English)In: 2016 18TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'16 ECCE EUROPE), Institute of Electrical and Electronics Engineers (IEEE), 2016, article id 7695545Conference paper, Published paper (Refereed)
Abstract [en]

The electronics industry is progressing towards the high density board solutions due to the requirement of compact and intelligent electronic systems. In order to meet the industry demands, the power system is required to be of high power density. This article proposes one of the solution to improve the power density for the medium power applications. In phase shifted full bridge converter, the intrinsic leakage inductance of the main transformer is not high enough to obtain the zero voltage switching of the power switches for the entire operating conditions. An additional shim inductor is usually connected in series with the primary winding of the main transformer to increase the collective leakage inductance. This additional shim inductor degrades the power density of the converter. This paper proposes a method to embed and control the resonance inductance inside the main transformer. In addition to the increased inter-winding spacing, this paper proposes a practical approach to integrate the ferrite rods inside the main transformer for further increase in the leakage inductance. A power transformer is constructed and investigated by using the modelled equations to estimate the leakage inductance. A prototype phase shifted full bridge converter is also developed to investigate the performance of the proposed transformer. The converter is designed for the switching frequency of 400kHz, and tested up to 600watts output power at the input voltage of 200Vdc. The performance of the proposed converter is also compared with the converter of using an external inductor. The investigations show that, in addition to the improved power density, the converter with the proposed transformer is more efficient than the converter with the traditional transformer.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2016
Series
European Conference on Power Electronics and Applications, ISSN 2325-0313
Keywords
ZVS converter, Transformer, Device modelling, High power density systems, Efficiency
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-29392 (URN)10.1109/EPE.2016.7695545 (DOI)000386637300294 ()2-s2.0-84996605370 (Scopus ID)STC (Local ID)STC (Archive number)STC (OAI)
Conference
18th European Conference on Power Electronics and Applications (EPE), SEP 05-09, 2016, GERMANY
Available from: 2016-12-02 Created: 2016-12-02 Last updated: 2017-06-29Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0208-9112

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