Yilmaz Sozer

Yilmaz Sozer
University of Akron · Department of Electrical and Computer Engineering

PhD

About

288
Publications
37,423
Reads
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3,384
Citations
Additional affiliations
August 2009 - present
University of Akron
Position
  • Professor (Associate)

Publications

Publications (288)
Article
Multiphysics analysis and experimental validation of acoustic noise reduction in a high pole count, high power, switched reluctance machine (SRM), through skewing are explored in detail in this work. An iterative optimization strategy covering electromagnetic, structural, and thermal domains is proposed to investigate the effect of different skewin...
Article
State of charge (SOC) balancing of battery cells is very crucial for the battery management system (BMS) to prolong the operational lifetime of the battery system. In this paper, an adaptive control algorithm is proposed to balance the SOCs for a series-connected battery system. The control strategy achieves power balancing using the current-SOC dr...
Article
Full-text available
The objective of this paper is to determine the location and size of the renewable energy sources (RESs) to be installed in microgrid networks having multiple distributed generators (DGs). Since RESs have faster dynamics and low inertia, microgrid sources could encounter large disturbances in their power productions when RES is deployed. As the mag...
Article
Full-text available
This study proposes a flexible, compact, efficient, and cost effective electric vehicle-to-electric vehicle (V2V) charge sharing solution that will lead to faster and wider customer adoption of electric vehicles (EVs) as an alternative to current grid-to-vehicle charging methodologies. The energy will be transferred between EVs using a bidirectiona...
Article
Acoustic noise reduction is one of the main topics of switched reluctance motor (SRM) developments. One of the effective methods is flattening three-phase radial force sum. This method is verified in experiments by optimizing the current profile. Novel current waveforms have been proposed recently for acoustic noise reduction without sacrificing th...
Article
This study focusses on reducing the battery size requirements of electric busses using battery charging and speed profile optimization. To minimize the energy consumption costs and the battery size, an opportunity charging city bus networks have been investigated. An electric bus architecture, traffic, weather and road conditions, as well as the dr...
Article
Full-text available
Switched reluctance machine (SRM) drive requires a larger dc-link capacitor due to the low-frequency harmonics in battery current which is generated during the current commutation between phases. Installing a bulky capacitor bank in the drive has a significant impact on the cost and the overall volumetric power density of the drive. This paper anal...
Article
Noise, vibration and harshness (NVH) issue in switched reluctance machines (SRM), originating from their doubly salient structure and unique principle of operation, is addressed in this work by proposing a structural design modification in the stator which increases stiffness to mass ratio of the structure. A 24-slot 16-pole (24s/16p) SRM designed...
Article
Full-text available
With growing interest in electrification in automotive industries, the selection of suitable electric machine type based on application requirements are most important. In this paper, three electric machine types; axial flux machine (AFM), interior permanent magnet machine (IPM) and switched reluctance machine (SRM) are chosen to drive engine acces...
Article
Full-text available
The tradeoff between the operating cost and the reliability of microgrids imposes challenges of having cost-effective power dispatch and reliable operations. The work presented in this paper optimally solves this issue in a microgrid that contains PV, dispatchable generator, and storage battery. Flexible control algorithms are developed to enable h...
Article
This paper proposes a differential power processing (DPP) configuration applied to a series photovoltaic (PV) string. The proposed configuration operates each PV element at its local maximum power point (MPP) while processing only a small portion of its total generated power through the modular-integrated converters. The current processed through e...
Conference Paper
This paper presents a hook-shaped stator core with the ring winding transverse flux machine (TFM) for direct-drive wind turbine application. The proposed topology has a double stator with ring winding and a single rotor with a flux concentrating method to increase the air gap flux density. It has an axial air gap and better magnet utilization, whic...
Conference Paper
Noise, vibration, and harshness (NVH) in electric machines are mainly of electromagnetic and structural origin. This research focuses on isolating the structural and electromagnetic impacts on NVH performance, in a fractional slot concentrated winding (FSCW) permanent magnet synchronous machine (PMSM), brought by variation of different design param...
Conference Paper
A high saliency Transverse Flux Machine (TFM) with a novel rotor structure for traction application is proposed in this paper. The proposed topology has a double stator and a single rotor. For the stator, E shaped core and the concentrated windings are used. An axial airgap is used in the proposed topology, which helps in improving the torque densi...
Conference Paper
Full-text available
Switched reluctance machine (SRM) produces high noise and vibration due to its inherent torque production mechanism. This paper presents a new damping method for the SRM to improve the vibrational performance of the machine by using a damping material. Back iron of the stator pole is modified to place the damping material between the stator and the...
Conference Paper
This study proposes simultaneous DC-link current ripple, torque ripple, and radial force ripple reduction by injecting optimal phase currents obtained from multi-objective optimization techniques while maintaining the output performance of the machine. The user can select the weighting for different objectives in the optimization process depending...
Conference Paper
Full-text available
This paper analyzes the impact of interleaved PWM techniques on transverse flux machine (TFM) drive to achieve high volumetric and gravimetric power density along with high efficiency and low common-mode noise. Interleaving helps the dominant dc-link current ripple content shifts to twice the switching frequency, and a reduced amount of dc-link cap...
Conference Paper
This research focuses on wide speed range noise, vibration and harshness (NVH) performance comparison and optimization of different fractional slot concentrated winding permanent magnet synchronous machines (PMSM) for automotive application through a unit force response-based method of vibration prediction called vibration synthesis. Process verifi...
Conference Paper
Harmonic injection in dc-link current through phase current shaping is a well-known method to reduce the dc-link ripple in Switched Reluctance Machine (SRM) drive system while maintaining the machine performance. However, this method is susceptible to the accuracy of the position and the current sensors. This paper presents an analytical approach t...
Conference Paper
Phase current shaping is a common approach to reduce the radial force ripple and thus improve the noise, vibration, and harshness (NVH) performance of the switched reluctance machine (SRM). However, this method is reliant on the accuracy of the position and the current sensors. This paper presents an analytical approach to model the effect of posit...
Article
The use of direct-drive machines in renewable and industrial applications is increasing at a rapid rate. Transverse flux machines (TFMs) are ideally suited for direct-drive applications due to their high torque density. This article presents a comprehensive review of permanent magnet (PM) TFMs for direct-drive applications. It introduces TFMs and t...
Chapter
This chapter covers the topics of core loss measurement, analysis, modeling, and estimation in electric machines. First, the factors that influence the core losses are discussed, followed by a detailed literature review of core loss models. Then, core loss measurement techniques are reviewed, and measurement accuracy is investigated in various aspe...
Article
Switched Reluctance Machines (SRMs) have been studied by many researchers as an alternative to other types of electrical machines for use in electric and hybrid vehicle applications. SRMs are fault tolerant and have wide speed operating range. However, they suffer from several disadvantages including high vibration, acoustic noise and torque ripple...
Article
Full-text available
A low-loss and lightweight core material, with applications in electrical machinery, is made of highly packed and insulated magnetic microwires (MWs). These MWs are aligned in such a way as to guide the flux in the rotor/stator, with the ultimate goal of increasing efficiency and substantially reducing core losses. Commercial FebalNi29Co17-based MW...
Article
Full-text available
In this paper, micromagnetic analysis of an array of long magnetic nanowires (NWs) embedded in a nonmagnetic matrix is performed. It is found that for NWs with diameters on the order of a hundred nanometers, the anisotropy and exchange energies are negligible, so the total free energy is a sum of the Zeeman and magnetostatic energies. The minimum m...
Article
In this paper, a new protection scheme for DC electrical traction supply systems is introduced. The method is based on continuous high-frequency impedance measurement of the electric supply system. The correlation between high-frequency impedance of traction supplies and the physical integrity of the system is shown. The measurement is synthesized...
Article
This paper proposes an adaptive democratic current sharing control scheme for interleaved dc-dc converters under faulty condition. The proposed fault tolerant control approach can achieve the desired output voltage generation, and equal current sharing among the remaining healthy modules as more and more modules fail. The main idea is to adaptively...
Article
This research examines the vibration and thermal characteristics of double-sided flux concentrating Transverse Flux Machines (TFM), designed for direct drive application. Two TFM prototypes with different stator cores, one with Quasi U-Core and the other with E-Core, has been used for the study. 3D Finite Element Analysis (FEA) has been carried out...
Conference Paper
This research aims at experimental determination of modal damping ratios in fractional slot concentrated winding (FSCW) permanent magnet synchronous machines (PMSM) and utilizing that information to refine finite element analysis (FEA) based structural simulations for better prediction of vibration behavior. 12 slot-10 pole (12s10p) surface mounted...