Yazar "Yasa, Yusuf" seçeneğine göre listele

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  • Küçük Resim Yok
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    Acoustic Noise Mitigation of Switched Reluctance Machines With Leaf Springs
    (Ieee-Inst Electrical Electronics Engineers Inc, 2023) Yasa, Yusuf; Sozer, Yilmaz; Garip, Muhammet
    In this article, a leaf spring insertion to the stator back iron is proposed to reduce vibration and acoustic noise in a switched reluctance machine (SRM). The back iron of the tooth tip is curved out and the material made up of carbon spring steel is placed to dampen the vibration due to radial force. A 6/4 stator/rotor pole SRM is designed and its natural vibration mode frequencies are determined through finite-element analyses. The optimal current waveform is applied to the SRM model using the multidisciplinary coupled simulation method to determine the radial force with the harmonic orders. In the final step, the proposed leaf spring architecture is optimized to achieve the most dampening for the effective radial force harmonic orders. The simulation and experimental results confirmed the effectiveness of the leaf spring insertion in reducing the noise and vibration in SRMs.
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    Alçaltıcı/Yükseltici Dc/Dc/Ac Eviricilerle Yüksek Performanslı Anahtarlamalı Relüktans Motoru Sürücü Sistemi Tasarımı Ve Gerçeklemesi
    (2021) Tekgun, Burak; Boynuegrı, Alı Rıfat; Yasa, Yusuf; Alan, Irfan
    Anahtarlamalı relüktans motorları (ARM) 1800?lü yılların ortalarında keşfedilmesine rağmen, 1960?lı yıllarda yarı iletken anahtarların icat edilmesine kadar potansiyeli anlaşılamamış makinalardır. Modern yarı iletken teknolojisinin icadı ve gelişmesi ile birlikte ARM?lerin kullanımı yaygınlaşmıştır. ARM?ler basit yapıları, düşük üretim maliyetleri ve sağlamlıklarından dolayı birçok uygulamada tercih edilmişlerdir. Geleneksel olarak ARM, her bir faz için iki yarı iletken anahtar ve iki diyot kullanılarak oluşturulan sürücülerle sabit giriş gerilimi işlenerek, sırasıyla fazlar enerjilendirilmektedir. Faz sargılarındaki akımın enerjilendirilme esnasında yükselme süresi ve enerji kesildiği durumdaki akımın azalma süresi DC bara voltajına bağlıdır. Bu durum uygulamalarda enerjilendirme süresinin akımın sıfıra gitme süresi de göz önüne alınıp kısa tutulmasına, dolayısıyla komütasyon esnasında düşük tork üretimine, yüksek tork salınımına ve ortalama tork üretiminde azalmaya sebep olmaktadır. Bu projede, geleneksel sürücü topolojisinden farklı olarak ARM, bir DC/DC dönüştürücü ve tek fazlı bir tam-köprü evirici yardımı ile ideale yakın bir enerjilendirme akımı oluşturularak ARM daha yüksek performans ile kontrol edilmesi sağlanmıştır. Projede önerilen ARM sürücüsü her bir fazı bir DC/DC dönüştürücü ve bir tam-köprü evirici içeren modüler yapılı sürücülerden oluşmaktadır. Önerilen sürücü yapısını geleneksel ARM topolojilerinden ayıran özelliği DC/DC dönüştürücü devresidir. Burada makinanın faz sargılarının ihtiyaç duyduğu akım dalga şekli DC/DC dönüştürücü ile sağlanmaktadır. Tork üretiminin pozitif olabilmesi için stator ve rotor kutuplarının tam hizalandığı andan kısa bir süre önce negatif gerilim uygulanarak, faz akımının hızlı bir şekilde kesilmesi gerekmektedir. Bu durumda ise gerilim önerilen devredeki tam-köprü devresi yardımıyla tersine çevrilerek ve DC/DC dönüştürücünün çıkış gerilimi en yüksek seviyesine getirilmek suretiyle akımın hızlı şekilde sıfıra inmesi sağlanmıştır ve böylelikle makinanın performansı artmıştır. sadece DC/DC çevirici katında yüksek frekanslı anahtarlama olduğundan anahtarlama kayıplarının azalarak ve geleneksel topolojiye göre daha yüksek verim sağlanmıştır. Önerilen sürücü sisteminin AC motorların sürücüleri olarak yenilenebilir enerji sistemlerinde ara yüz elemanı olarak uygulanabilir olması, arıza giderme zamanında önemli ölçüde azalmaya neden olarak üretimdeki sürdürülebilirliğin artırılmasına destek olacağı öngörülmektedir.
  • Küçük Resim Yok
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    C-Rate- and Temperature-Dependent State-of-Charge Estimation Method for Li-Ion Batteries in Electric Vehicles
    (Mdpi, 2024) Aslan, Eyyup; Yasa, Yusuf
    Li-ion batteries determine the lifespan of an electric vehicle. High power and energy density and extensive service time are crucial parameters in EV batteries. In terms of safe and effective usage, a precise cell model and SoC estimation algorithm are indispensable. To provide an accurate SoC estimation, a current- and temperature-dependent SoC estimation algorithm is proposed in this paper. The proposed SoC estimation algorithm and equivalent circuit model (ECM) of the cells include current and temperature effects to reflect real battery behavior and provide an accurate SoC estimation. For including current and temperature effects in the cell model, lookup tables have been used for each parameter of the model. Based on the proposed ECM, the unscented Kalman filter (UKF) approach is utilized for estimating SoC since this approach is satisfactory for nonlinear systems such as lithium-ion batteries. The experimental results reveal that the proposed approach provides superior accuracy when compared to conventional methods and it is promising in terms of meeting electric vehicle requirements.
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    Comprehensive Multidisciplinary Electric Vehicle Modeling: Investigating the Effect of Vehicle Design on Energy Consumption and Efficiency
    (Mdpi, 2024) Aslan, Eyyup; Yasa, Yusuf; Meseci, Yunus; Arabul, Fatma Keskin; Arabul, Ahmet Yigit
    In this study, an electric vehicle (EV) dynamic model is devised that amalgamates mechanical design aspects-such as aerodynamic effects, tire friction, and vehicle frontal area-with crucial components of the electrical infrastructure, including the electric motor, power converters, and battery systems. Verification of the model is executed through a comprehensive multidisciplinary analysis utilizing CATIA, ANSYS Electromagnetics, ANSYS Fluent, and MATLAB-Simulink tools, which are applied to evaluate two alternative lightweight EV prototypes. The process involves initial computations of critical inputs for the dynamic model, including aerodynamic lift (C1), drag coefficients (Cd), and frontal area (Af). Subsequent stages entail the detailed design and analysis of a 2 kW brushless permanent magnet electric motor in ANSYS Electromagnetics to map efficiency contours across various speed-torque values. Integration of these parameters into a MATLAB-Simulink dynamic model, connected with motor drive inverter and battery models, allows for simulation-based energy consumption analysis under race track slope profiles. Remarkably, the findings underscore the considerable impact of neglected parameters on energy consumption, often exceeding fifty percent of the total. Consequently, an energy-efficient EV prototype is manufactured and rigorously tested under specified drive conditions, affirming the validation of the comprehensive multidisciplinary EV dynamic model.
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    Consideration of graphene material in PCM with aluminum fin structure for improving the battery cooling performance
    (WILEY, 2022) Aslan, Eyyüp; Aydın, Yusuf; Yasa, Yusuf
    Phase change material (PCM) based battery thermal management system (BTMS) provides even heat distribution and lower maximum temperature, but it suffers from low thermal conductivity. In this study, the impact of graphene additive on PCM was analyzed by presenting three experiments with various structures to solve PCM's low thermal conductivity problem. The results demonstrate that there is no positive impact of graphene additive in the first and third structures. The PCM-graphene additive between the second structure's fins significantly improves the battery heat transfer by allowing the battery to cool down 1500 seconds earlier than the graphene-free structure. Moreover, a thermal equivalent circuit model was derived for the second structure because of its enhanced performance. It is shown that the model works accurately and proves its ability to control not only temperature fluctuations but also transient behavior of the battery. This model provides that the battery temperature can be analyzed without experimentation for different charge-discharge scenarios in lithium-ion batteries with a shorter computation time.
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    Sensorless Control of Synchronous Reluctance Motor Based on Active Flux Vector and Extended Kalman Filter
    (Springer Singapore Pte Ltd, 2022) Cebeci, Emre; Yasa, Yusuf
    The need for high performance and high control accuracy in electric motors has made modern motor control techniques popular. Modern control techniques often require position sensors integrated into the electric motor. As an alternative to position measurement, the position estimation methods offer a cost advantage within acceptable error results. In this study, a new sensorless control method that includes both Active Flux Observer (AFO) and Extended Kalman Filter (EKF) is proposed. The active flux vector is obtained using stator currents and voltage data. The active flux vector components are separated and rotor position estimation is made. An angular velocity estimation is made to this vector by different methods. In this article, EKF, which can make less angular velocity estimation errors than angular velocity estimation methods obtained by AFO and other methods, is proposed. To validate the proposed method, the synchronous reluctance motor was modeled and controlled with the predicted position information. By applying EKF to the model, the load torque is estimated as well as the rotor angular velocity. Regarding position estimation, the results show that the EKF method is up to 50% more successful in the ramp and step load torques than other methods such as the Phase Locked Loop (PLL) and Flux Derivation Method in terms of rotor angular velocity estimation error.