Browsing by Author "Ozdemir, Mehmet Akif"

Now showing 1 - 3 of 3

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: 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 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%.