Browsing by Author "Aydemir, Mehmet Timur"

Now showing 1 - 14 of 14

Citation Count: 5
A 1-kW wireless power transfer system for electric vehicle charging with hexagonal flat spiral coil
(Tubitak Scientific & Technical Research Council Turkey, 2021) Aydin, Emrullah; AydemIr, M. Timur
Wireless power transfer (WPT) technology is getting more attention in these days as a clean, safe, and easy alternative to charging batteries in several power levels. Different coil types and system structures have been proposed in the literature. Hexagonal coils, which have a common usage for low power applications, have not been well studied for high and mid power applications such as in electric vehicle (EV) battery charging. In order to fill this knowledge gap, the self and mutual inductance equations of a hexagonal coil are obtained, and these equations have been used to design a 1 kW WPT system with hexagonal coils for a mid-power stage EV charging. The theoretical and simulation results have been validated with an implementation in the laboratory and a DC-to-DC power efficiency of 85% is achieved across a 10 cm air gap between the perfect aligned coils. The misalignment performance of the system was observed for different positioning of the secondary coil, and the output power variation is given. In addition, the effect of shielding on magnetic field exposition of a driver sitting in an EV was obtained, and these simulation results were compared in order to check the compliance with international health standards.
Citation Count: 30
A Comprehensive Review on Wireless Capacitive Power Transfer Technology: Fundamentals and Applications
(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Erel, Mehmet Zahid; Bayindir, Kamil Cagatay; Aydemir, Mehmet Timur; Chaudhary, Sanjay K.; Guerrero, Josep M.
Capacitive power transfer (CPT) technology is becoming increasingly popular in various application areas. Due to its limitations, such as low frequency, low coupling capacitance, and the high voltage stress on metal plates, the studies on high power CPT applications fell behind previously. Therefore, the wideband gap (WBG) semiconductor devices and the compensation topologies are further adopted to tackle these limitations. The main purpose of the paper is to review CPT applications in terms of performance parameters, advantages, disadvantages, and also challenges. Initially, the basic principles of CPT technology are examined, which cover compensation topologies, coupler structures, transfer distance, power electronic components, and system control methods. Then, CPT applications are evaluated for performance parameters (i.e., power level, operation frequency, system efficiency, transfer distance) along with compensation types, inverter types, and coupler types. The applications are categorized into six main groups according to industrial topics as safety, consumer electronics, transport, electric machines, biomedical, and miscellaneous. Herein, power level changes from mu W to kW ranges, the operation frequency varies from 100s of kHz to 10s of MHz ranges as well. The maximum system efficiency is recorded as 97.1 %. The transfer distance varies from mu m range to 100s of mm ranges. The full-bridge inverter topology and four-plate coupler structure are noticeable in CPT applications. Finally, advantages, disadvantages, and challenges of CPT applications are evaluated in detail. This review is expected to serve as a reference for researchers who study on CPT systems and their applications.
Citation Count: 1
Design and Implementation of a 10 Kv/10 Kw High-Frequency Center-Tapped Transformer
(Springer, 2022) Rahman, Showrov; Candan, Muhammed Yusuf; Tamyurek, Bunyamin; Aydin, Emrullah; Mese, Huseyin; Aydemir, M. Timur
High voltage high-frequency (HVHF) transformers have a crucial part in the realization of high voltage direct current (HVDC) isolated power supplies. Nevertheless, they are the bulkiest component in the system besides being one of the major contributors to the power losses. Special care is therefore required to design HVHF transformers. The main objective of this paper is to design and implement a high voltage (10 kV), high-frequency (50 kHz) center-tapped transformer with high efficiency, small size, and low cost. The proposed transformer is designed as part of a 100 kV, 10 kW DC/DC converter for supplying power to a particle accelerator. The proposed transformer steps up the input voltage (500 V) to 10 kV. Then, a five-stage full-wave Cockcroft-Walton voltage multiplier (CWVM) is used for boosting the voltage to 100 kV. A detailed step-by-step design guideline for designing an HVHF transformer is also presented. To reduce the transformer's parasitic capacitance, the secondary windings are wrapped in segments. This taken approach has been illustrated in the paper and later verified through finite element analysis (FEA). The FEA analysis shows that the transformer parasitic capacitance has reduced significantly. Following the presented design guideline, the implemented prototype transformer has been built and later tested with a single-stage CWVM. The experimental results demonstrate that the prototype transformer has successfully met the design requirements including the small size, less weight, and low-cost objectives.
Citation Count: 2
Design and Practical Implementation of a Parallel-Switched Power Factor Correction Boost Converter
(IEEE, 2021) Rahman, Showrov; Kosesoy, Yusuf; Ozdemir, Mehmet Akif; Simsek, Oguz; Aydemir, M. Timur; Chub, Andrii
In the past years, applications of Power Factor Correction (PFC) boost converter have increased significantly. One recent application field that requires an efficient PFC boost converter is the Wireless Power Transfer system (WPT). In this paper, the design of a single-phase PFC boost converter is presented. The proposed converter comprises three parallel switches to reduce the component stress and ensuring safe circuit operation. It utilizes FAN6982 Continuous Conduction Mode (CCM) controller. The design of the controller circuit and the controller parameter specifications are presented. Design guidelines for components are provided. The designed PFC boost converter is first validated in PSIM simulation software and then a 1.5 kW/ 350 V-dc prototype is implemented. The experimental results verify that the PFC boost converter achieves the power factor of 0.99 at the full load.
Citation Count: 0
Dual Side Control Design for a 600w Lcc Compensated Wireless Power Transfer System
(Institute of Electrical and Electronics Engineers Inc., 2022) Pashaei, A.; Aydin, E.; Aydemir, M.T.
The purpose of this paper is to design a dual side control for a 600 W LCC resonant WPT electrical bicycle with an 85 kHz resonant frequency. Primary side control use inverter voltage and current to determine mutual inductance and load value in coils misalignment case. The secondary side control uses a DC-DC converter that has two voltage and current feedback with a PI controller to achieve CC/CV charging in the battery. Additionally, with primary side control the high-frequency inverter operates in ZVS mode. Optimal design parameters are obtained and results and control method feasibility validated by simulations. © 2022 IEEE.
Citation Count: 24
Inductive Power Transfer for Electric Vehicle Charging Applications: a Comprehensive Review
(Mdpi, 2022) Aydin, Emrullah; Aydemir, Mehmet Timur; Aksoz, Ahmet; El Baghdadi, Mohamed; Hegazy, Omar
Nowadays, Wireless Power Transfer (WPT) technology is receiving more attention in the automotive sector, introducing a safe, flexible and promising alternative to the standard battery chargers. Considering these advantages, charging electric vehicle (EV) batteries using the WPT method can be an important alternative to plug-in charging systems. This paper focuses on the Inductive Power Transfer (IPT) method, which is based on the magnetic coupling of coils exchanging power from a stationary primary unit to a secondary system onboard the EV. A comprehensive review has been performed on the history of the evolution, working principles and phenomena, design considerations, control methods and health issues of IPT systems, especially those based on EV charging. In particular, the coil design, operating frequency selection, efficiency values and the preferred compensation topologies in the literature have been discussed. The published guidelines and reports that have studied the effects of WPT systems on human health are also given. In addition, suggested methods in the literature for protection from exposure are discussed. The control section gives the common charging control techniques and focuses on the constant current-constant voltage (CC-CV) approach, which is usually used for EV battery chargers.
Citation Count: 0
Investigation of External Factors for Wireless Capacitive Power Transfer Systems
(Univ Osijek, Tech Fac, 2023) Erel, Mehmet Zahid; Bayindir, Kamil Cagatay; Aydemir, Mehmet Timur
Capacitive power transfer (CPT) technology has gained more and more importance in recent years. This paper investigates the effects of temperature and relative humidity on CPT system performance. The conventional four-plate horizontal and vertical coupler structures are built to observe the variations of coupling capacitances under external factors. The pressure of the coupler ambient is kept constant, and the effects of temperature and relative humidity are reviewed separately. The different temperature (25 - 105 & DEG;C) and relative humidity (43 - 80% RH) levels are reviewed in these scenarios. The obtained results indicate that the values of coupling capacitances are inversely proportional to the temperature level, whereas the values of coupling capacitances are directly proportional to the relative humidity level. In addition, the visible changes happen in coupling capacitances after 45 & DEG;C and 55 & DEG;C for horizontally and vertically arranged four-plate coupler structures, respectively. It is also observed that relative humidity level becomes a critical point after 60% RH for both coupler structures. Among the coupling capacitances, the main capacitances are the most affected during the variations for both couplers. This study is expected to be a reference for the researchers on external factors in CPT systems.
Citation Count: 1
A Load Adaptive Cascade Pi Controller for Buck Converters Operating in Wide Load Range in Cathodic Protection Systems
(IEEE, 2021) Ozdemir, Mehmet Akif; Simsek, Oguz; Aydemir, Mehmet Timur
This paper proposes a simple cascade PI controller for Buck converter to be used in impressed current cathodic protection (ICCP) systems which aim to operate in wide voltage and current ranges for any load condition. The Buck converter with cascade controller structure is a frequently used topology in ICCP systems to prevent buried steel pipelines from corrosion. Changes in the environment in which the pipe is embedded force the converter to operate at wide load and voltage ranges. However, in average current mode controllers, the gain of the current loop varies significantly with the load. At light loads, the inner current loop slows down dramatically and may stay behind the outer voltage loop. In order to solve these issues and to maintain the regulation of the pipeline voltage and the average load current, this paper presents a simple cascade PI controller whose coefficients are adapted to the changing load. The small signal analysis of the Buck converter in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is performed and variables determining the transfer characteristics are examined. For the proposed controller, a design criteria based on circuit parameters have been established. With the parameters obtained by the proposed method, a sample cascade controller is designed and compared with classical PI controller in simulation. Also, a digitally controlled 100-W converter prototype is built to validate the performance.
Citation Count: 0
A New Capacitive Coupler Design for Wireless Capacitive Power Transfer Applications
(Elsevier - Division Reed Elsevier India Pvt Ltd, 2023) Erel, Mehmet Zahid; Bayindir, Kamil Cagatay; Aydemir, Mehmet Timur
Capacitive power transfer (CPT) technology has become a promising alternative solution for wireless charging applications. This paper proposes a novel coupler design to form a resonant capacitor by inserting dielectric material between two bent metal plates for each primary and secondary circuit. The main purpose of the proposed coupler is to eliminate the external capacitors and solve the low coupling capacitance for CPT applications. A comparison to the conventional four-plate coupler is presented, which shows specifically higher coupling capacitance, lower required inductance, and lower cost. Finally, the effectiveness of the proposed coupler structure is verified by simulation and experimental results. (c) 2023 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Citation Count: 6
A New Semi-Analytical Approach for Self and Mutual Inductance Calculation of Hexagonal Spiral Coil Used in Wireless Power Transfer Systems
(SPRINGER, 2021-01) Aydın, Emrullah; Yıldırız, Emin; Aydemir, M. Timur
Several methods have been proposed in the literature for the calculation of self and mutual inductance. These methods include the use of complex integral analysis, the necessity of having primary and secondary coils with the same dimensions and the limitations of the ratio of the coil dimension to the distance between the coils. To overcome these restrictions, a new semi-analytical estimation method has been proposed in this paper. Calculation the self and mutual inductance by using the same basic formula which is based on Biot Savart Law prevents the formation of complex integrals and helps create a simple solution method. In order to verify the results obtained with the analytical approach, two hexagonal coils with 10 and 20 cm outer side lengths were produced by using litz wire with a conductive cross section of 1.78 mm(2). The results obtained with the new approach are compared with the finite element analysis, other work presented in the literature and experimental results in order to prove the accuracy of the proposed method.
Citation Count: 0
A Novel Hybrid Coil Design and Implementation for Wireless Power Transfer Systems
(Edp Sciences S A, 2024) Pashaei, Ali; Aydin, Emrullah; Ozdemir, Mehmet Akif; Kosesoy, Yusuf; Aydemir, Mehmet Timur
Wireless Power Transfer (WPT) has been drawing a lot of attention in the last ten years parallel with the market increase in electric vehicles. Although conductive charging methods are still the preferred ones, WPT-based charging systems are used as clean and flexible alternatives. At the center of these systems are the transmitting and receiving coils, and different coil types have been proposed in the literature. This study proposes a square-hexagonal hybrid coil structure to increase magnetic coupling by shaping the magnetic field. In addition, this design aims to minimize the coupling coefficient variation for misaligned coils which is one of the most significant problems in WPT systems. A 3D model of the coils was created and analyzed using ANSYS, Maxwell software. Compared to the conventional square coil structure the coupling coefficient of the proposed structure is less affected by misalignment on the x and y axes, and as a result, it has a better efficiency. In addition, a WPT system operating at 50 W, 85-kHz is designed and tested in a laboratory environment. The FEA analyses and experimental application results largely overlap, and accordingly, the coil-to-coil efficiency of our WPT system was 93.5% and the overall efficiency of the system was 87%.
Citation Count: 0
Parallel-Input Series-Output Z-Source Converters for High Voltage Dc Power Supplies
(Institute of Electrical and Electronics Engineers Inc., 2023) Ozdemir,M.A.; Aydin,E.; Dag,B.; Tamyurek,B.; Aydemir,M.T.
High Voltage DC power supplies typically employ a high voltage high frequency transformer to step-up the voltage generated by a high frequency inverter. Generally, the step-up ratio of the transformers is high and therefore the effect of the stray capacitance and inductance values is amplified, deteriorating the inverter operation. LCC converters utilizing these stray capacitors are suggested to generate soft switching for better efficiency, but this increases the complexity. Also, the varying nature of the stray capacitance may complicate the control. In this paper, a modular, Parallel-Input Series-Output converter utilizing two z-source dc-dc converters is proposed to step a 350V input to generate 2-kV, 2-kW output. Simulation and experimental results prove that impedance source converters which are generally used in renewable energy applications can also be used at high voltage applications. © 2023 IEEE.
Citation Count: 3
Yeni Nesil Yüksek Gerilim Kazançlı ve İzoleli Z-kaynak Da-da Dönüştürücü için K-faktör Tasarım Yöntemi ile Analog Denetleyici Tasarımı ve Uygulaması
(2021) Dağ, Bülent; Tamyürek, Bünyamin; Turan, Enes; Aydemir, M.Timur
Bu çalışmada yeni nesil yüksek gerilim kazançlı ve izoleli Z-kaynak da-da dönüştürücü için Kfaktör tasarım yöntemi kullanılarak analog denetleyici tasarımı ve uygulaması yapılmıştır.Denetleyici devresi ile oluşturulan kapalı çevrim dönüştürücü sistemi giriş geriliminde ve yüktebelirli sınırlar içerisinde değişim meydana gelmesine rağmen dönüştürücü çıkışında sabit çıkışgerilimi elde edilmesini sağlar. Denetleyici devresini tasarlamak için kullanılan K-faktörtasarım yöntemi ile geri besleme devresinin tasarımı belirli bir matematiksel denklem akışı ileelde edilir. Denetleyici devresinin elemanlarını hesaplamak için kullanılan matematiksel yöntemkapalı çevrim sistemin güvenilirliğini arttırmaktadır. Bu çalışmada ilk olarak K-faktör tasarımyöntemi ile yeni nesil bir Z-kaynak da-da dönüştürücü topolojisinin kapalı döngü denetimininteorik çalışması yapılmıştır. İkinci olarak PLECS de teorik çalışma sonuçları benzetim çalışmasıyapılarak incelenmiştir. Son olarak deneysel çalışma da yapılarak benzetim sonuçları vedeneysel sonuçlar karşılaştırılmıştır. Benzetim çalışması ve deneysel çalışma sonuçları K-faktörtasarım yöntemi ile oluşturulan denetleyicinin çıkış gerilimini denetim altına alabildiğinigöstermiştir. Sonuç olarak K-faktör tasarım yöntemi ile yeni nesil bir da-da dönüştürücü içingüvenilir bir kontrol yöntemi oluşturulabileceği gösterilmiştir.
Citation Count: 1
Yüksek Da Gerilim Uygulamaları için Empedans Kaynaklı Yükseltici Çevirici Tasarımı
(2023) Aydemir, Mehmet Timur; Dağ, Bülent; Özdemir, Mehmet Akif; Aydın, Emrullah; Tamyürek, Bünyamin
Bu çalışmada yüksek DA gerilimli bir güç kaynağında kullanılmak üzere yüksek kazançlı yeni nesil bir empedans kaynaklı yükseltici çeviricinin güç katı tasarımı yapılmıştır. Ele alınan empedans kaynaklı çevirici yeni geliştirilmiş bir topoloji olup, çeviricinin temel çalışma prensibi daha önceki bir çalışmada detaylı şekilde incelenmiştir. Bu çalışmada çeviricinin hedeflenen uygulamaya yönelik tasarımı için gereken gerilim-denge ve akım-denge eşitlikleri çıkarılmıştır ve bu eşitlikler kullanılarak uygun devre elemanları değerleri belirlenmiştir. Tasarlanan çeviricinin performansı Matlab-Simulink benzetim modeli ile doğrulanmıştır.