Murat Ayaz

Bio: Murat Ayaz is an academic researcher from Kocaeli University. The author has contributed to research in topics: Permanent magnet synchronous generator & Electromagnetic coil. The author has an hindex of 5, co-authored 35 publications receiving 94 citations.

Design considerations for dual winding permanent magnet synchronous machines

Abstract: This paper presents design and analysis performed for a dual winding electric machine. Windings of the machine are concentrated type so that electrical and magnetic isolation is maintained. For this reason, the proposed structure could be a reasonable candidate for fault tolerant applications. As required by some applications (electric accessory drive system (EADS) for hybrid electric vehicles), simultaneous motoring and generating operations can be implemented in a single housing of electric machine. Design considerations of the proposed electric machine are outlined in the paper. Also a comparison between distributed winding topology and concentrated winding topologies is performed. Finally experimental results discussed.

Analytical Modeling of Dual Winding Surface-mounted Permanent Magnet Synchronous Machine for Hybrid Electric Vehicle Accessory Drive Systems

Abstract: Fast and accurate electromagnetic torque calculation of unconventional Permanent Magnet Synchronous Machines (PMSMs) is very important in order to reduce design effort. Dual winding PMSMs (DWPMSMs) can be categorized as unconventional and commonly available fast design software that usually lacks predicting machine performance. In this study, an analytical modeling approach has been proposed to calculate electromagnetic torque of DWPMSMs, which has motor and generator windings in a single stator core. Conformal mapping is used for the calculation of flux levels at various locations in the machine. Radial and tangential components of flux densities due to magnet and winding are determined analytically. Instantaneous value of electromagnetic torque due to generator or motor windings is calculated by integrating the Maxwell stress tensor in the middle of the air gap. Accuracy of the proposed analytical solution is confirmed with finite element analysis results. For further validation, an experimental...

An equivalent circuit model for switched reluctance motor

Abstract: The switched reluctance motor (SRM) is an old member of machine family. Its simple structure, ruggedness, and inexpensive manufacturability make them attractive for industrial applications. This paper presents an equivalent circuit model for switched reluctance motor. Its linear model and dynamics are discussed in detail. Parameters and its approximate equivalent circuit are obtained by using linear model and dynamics of the switched reluctance motor. Simulation studies are performed for phase currents and the steady-state motor operation.

A comprehensive review on hybrid electric vehicles: architectures and components

Abstract: The rapid consumption of fossil fuel and increased environmental damage caused by it have given a strong impetus to the growth and development of fuel-efficient vehicles. Hybrid electric vehicles (HEVs) have evolved from their inchoate state and are proving to be a promising solution to the serious existential problem posed to the planet earth. Not only do HEVs provide better fuel economy and lower emissions satisfying environmental legislations, but also they dampen the effect of rising fuel prices on consumers. HEVs combine the drive powers of an internal combustion engine and an electrical machine. The main components of HEVs are energy storage system, motor, bidirectional converter and maximum power point trackers (MPPT, in case of solar-powered HEVs). The performance of HEVs greatly depends on these components and its architecture. This paper presents an extensive review on essential components used in HEVs such as their architectures with advantages and disadvantages, choice of bidirectional converter to obtain high efficiency, combining ultracapacitor with battery to extend the battery life, traction motors’ role and their suitability for a particular application. Inclusion of photovoltaic cell in HEVs is a fairly new concept and has been discussed in detail. Various MPPT techniques used for solar-driven HEVs are also discussed in this paper with their suitability.

A novel computational approach for harmonic mitigation in PV systems with single-phase five-level CHBMI

Abstract: In this paper, a novel approach to low order harmonic mitigation in fundamental switching frequency modulation is proposed for high power photovoltaic (PV) applications, without trying to solve the cumbersome non-linear transcendental equations. The proposed method allows for mitigation of the first-five harmonics (third, fifth, seventh, ninth, and eleventh harmonics), to reduce the complexity of the required procedure and to allocate few computational resource in the Field Programmable Gate Array (FPGA) based control board. Therefore, the voltage waveform taken into account is different respect traditional voltage waveform. The same concept, known as “voltage cancelation”, used for single-phase cascaded H-bridge inverters, has been applied at a single-phase five-level cascaded H-bridge multilevel inverter (CHBMI). Through a very basic methodology, the polynomial equations that drive the control angles were detected for a single-phase five-level CHBMI. The acquired polynomial equations were implemented in a digital system to real-time operation. The paper presents the preliminary analysis in simulation environment and its experimental validation.

Improved performance of PEM fuel cells stack feeding switched reluctance motor using multi-objective dragonfly optimizer

Abstract: In this article, a switched reluctance motor (SRM) powered by autonomous stacked proton exchange membrane fuel cells (PEMFC)’s stack with the purpose of optimizing their operating performances is addressed. Three key performance indices are examined that include: (1) torque per ampere ratio, (2) torque smoothness factor and (3) average starting torque. The later mentioned adapted indices characterize the objective functions that can be optimized individually and concurrently using a novel application of multi-objective dragonfly approach (MODA). The MODA is applied to generate the optimal turn (on/off) angles of H-bridge converter and the gains of a proportional-integral speed controller. A Pareto front optimal solutions are made, and the final best compromise solution is carefully chosen. The terminal voltage of the PEMFC is fine controlled by a boost converter, to overcome the noticeable decline of its voltage profile with the increase in loading current. The system under study is demonstrated at various loading conditions with necessary comparisons to other recent competing methods complete with subsequent discussions. The cropped numerical results indicate that PEMFC energy saving, reduction in SRM torque ripples and PEMFC current ripples can be enhanced. In addition, higher average starting torque of the SRM is realized.