Mehmet Timur Aydemir

Mehmet Timur Aydemir

orcid

Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
30 December 2021 in IEEE Access
Verified
Journal Article
Open access
MEMehmet Zahid EREL
Mehmet Zahid EREL
KBKamil Cagatay Bayindir
Kamil Cagatay Bayindir
MAMehmet Timur Aydemir
Mehmet Timur Aydemir
Sanjay Kumar ChaudharySanjay Kumar Chaudhary
Sanjay Kumar Chaudhary
Josep M. GuerreroJosep M. Guerrero
Josep M. Guerrero
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 $\mu \text{W}$ 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 $\mu \text{m}$ 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.

20 September 2013 in IEEE Transactions on Power Electronics
Verified
Journal Article
Closed access
FEFatih Evran
Fatih Evran
MAMehmet Timur Aydemir
Mehmet Timur Aydemir
Fuel cell stacks and photovoltaic panels generate rather low dc voltages and these voltages need to be boosted before converted to ac voltage. Therefore, high step-up ratio dc-dc converters are preferred in renewable energy systems. A new Z-source-based topology that can boost the input voltage to desired levels with low duty ratios is proposed in this paper. The topology utilizes coupled inductor. The leakage inductance energy can efficiently be discharged. Since the device stresses are low in this topology, low-voltage MOSFETs with small RDS(on) values can be selected to reduce the conduction loss. These features improve the converter efficiency. Also, the converter has a galvanic isolation between source and load. The operating principles and steady-state analysis of continuous and discontinuous conduction modes are discussed in detail. Finally, experimental results are given for a prototype converter that converts 25 V dc to 400 V dc at various power levels with over 90% efficiency to verify the effectiveness of the theoretical analysis.

1 January 2013 in IET Power Electronics
Verified
Journal Article
Open access
PDF file
FEFatih Evran
Fatih Evran
MAMehmet Timur Aydemir
Mehmet Timur Aydemir
Continuous input currents and high step‐up ratios are desired from the dc–dc converters that work with renewable energy sources such as photovoltaic panels and fuel cells. Most dc–dc converters use transformers to have high step‐up ratios. There is another type of converters that use coupled inductors, but they need to operate at high duty cycles to increase the gain. These converters suffer from low efficiency values because of the leakage inductance values and long reverse recovery times of the diodes. A new dc–dc converter based on Z‐source topology is proposed in this study. It uses coupled inductors to increase the step‐up ratio. Its main features are high step‐up ratios, continuous input currents, high efficiency and galvanic isolation between input and output. Simulation and experimental results are given for a prototype converter that converts 25–400 V dc at 300 W with over 91% efficiency.

1 April 2014 in International Journal of Hydrogen Energy
Verified
Journal Article
Closed access
MŞMustafa Ergin Şahin
Mustafa Ergin Şahin
HOHalil İbrahim Okumuş
Halil İbrahim Okumuş
MAMehmet Timur Aydemir
Mehmet Timur Aydemir

19 April 2004 in IEEE Transactions on Applied Superconductivity
Verified
Journal Article
Closed access
GSG. Stumberger
G. Stumberger
MAMehmet Timur Aydemir
Mehmet Timur Aydemir
Damir ŽarkoDamir Žarko
Damir Žarko
TLT.A. Lipo
T.A. Lipo
High-temperature superconducting (HTS) material in bulk form is used to design a linear synchronous motor for an electromagnetic aircraft launch system. The motor is designed without an iron core. Stator coils are placed in the air while the permanent magnets used in conventional design of linear permanent magnet synchronous motors are replaced by the HTS bulk magnets. The physical, operational, and equivalent circuit parameters of the linear motor with HTS bulk magnets are compared with those of a linear permanent magnet synchronous motor and linear induction motor designed for the same application. Results show that utilizing superconducting magnets is only superior at temperatures below 40 K.

6 July 2022 in Energies
Verified
Journal Article
Open access
PDF file
EAEmrullah Aydin
Emrullah Aydin
MAMehmet Timur Aydemir
Mehmet Timur Aydemir
Ahmet AksözAhmet Aksöz
Ahmet Aksöz
MBMohamed El Baghdadi
Mohamed El Baghdadi
Omar HegazyOmar Hegazy
Omar Hegazy
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.