Browsing by Author "Ozdemir, Mehmet Akif"

Now showing 1 - 4 of 4

Citation - WoS: 4
Citation - Scopus: 9
Design and Practical Implementation of a Parallel-Switched Power Factor Correction Boost Converter
(IEEE, 2021) Rahman, Showrov; Özdemir, Serpil; Kosesoy, Yusuf; Aydemir, Mehmet Timur; 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 - WoS: 1
A Load Adaptive Cascade Pi Controller for Buck Converters Operating in Wide Load Range in Cathodic Protection Systems
(IEEE, 2021) Ozdemir, Mehmet Akif; Aydemir, Mehmet Timur; Simsek, Oguz; Özdemir, Serpil; 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 - WoS: 1
Citation - Scopus: 1
A Novel Hybrid Coil Design and Implementation for Wireless Power Transfer Systems
(Edp Sciences S A, 2024) Pashaei, Ali; Aydemir, Mehmet Timur; Özdemir, Serpil; 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%.
Solar Energy-Powered Wireless Charging System for Three-Wheeled E-Scooter Applications
(Pergamon-elsevier Science Ltd, 2025) Erel, Mehmet Zahid; Ozdemir, Mehmet Akif; Aydemir, Mehmet Timur
Wireless power transfer (WPT) is a remarkable charging technology that addresses the range limitations and complexity of light electric vehicles. This study presents a novel approach to a solar-powered WPT system designed for three-wheeled e-scooter applications. The proposed system offers compact, lightweight, and costeffective solution with a ferrite-less structure and a series-series (SS) compensation topology, resulting in enhanced system efficiency and adaptability. The compact and efficient converters are designed to enhance performance and reduce system size. A Proportional-Integral (PI) controlled Perturb and Observe (P&O) maximum power point tracking (MPPT) method is implemented to optimize energy extraction from three solar panels. The design is validated through comprehensive simulations and demonstrates a superior dynamic response over the Incremental Conductance MPPT (ICM) method. Performance tests confirm the reliability of the experimental prototype, achieving a system efficiency of 88.5 % at 300-W output power over a 100 mm transfer distance under fully aligned condition. Comparative analyses with existing solar-powered e-cycle systems highlight the proposed design's superiority in efficiency, cost-effectiveness, and adherence to safety standards. The results indicate that the proposed design enhances sustainable urban transportation by reducing carbon emissions and decreasing reliance on fossil fuels, facilitating the wider integration of renewable energy sources.