Multi-physics design optimisation of a GaN-based integrated modular motor drive system

Here, a multi-physics approach is presented for the design optimisation of an integrated modular motor drive (IMMD). The system is composed of a modular permanent magnet synchronous motor (PMSM) and a GaN-based modular motor drive power stage. The multi-physics model includes motor drive inverters and DC-link capacitor bank (electrical model), stator windings and rotor magnets (electromagnetic model), heat sink (thermal model), and a geometrical model. The main purpose of the design optimisation is to obtain the highest power density possible, which is quite critical in integrated drives. Due to the integrated structure, the system has several interdependencies and parameters are selected based on those relationships. An 8kW IMMD system design is proposed from the developed optimisation tool and evaluated. The resultant system has a power density of 0.71kW/lt, drive efficiency of 98.3%, and motor efficiency of 96.6%

Evaluation of Semicircular Canal Functions by the Video Head Impulse Test (vHIT) in Individuals with Motion Sickness

Background: In the occurrence of motion sickness, the functioning of the vestibular system in harmony has an important role. Aim/Objective: To evaluate the effectiveness of the vestibular system in individuals with motion disease with the Video Head Impulse Test (vHIT) device, which evaluates the vestibulo-ocular reflex (VOR). Materials and Methods: Thirty individuals with motion sickness (21 females, 9 males) and 30 healthy individuals (11 females, 19 males) without any vestibular complaints were examined with the vHIT device. All participants were older than 18 years. Results: It was observed that VOR gain values of the individuals with motion disease were significantly lower than those of the healthy individuals. Asymmetry values of the individuals with motion disease in all semicircular canals were higher than those of the healthy individuals; however, this difference was statistically significant only in the anterior semicircular canal. Conclusion and Significance: The observation of low gain values in all semicircular canals in individuals with motion sickness suggested that individuals with motion sickness may experience dysfunction in the sensory organelles in the vestibular system. Studies with larger case series and audiological test batteries will help us better understand motion sickness. Keywords: Motion sickness; vestibular; vHIT DOI: 10.7176/JHMN/79-05 Publication date:August 31st 202

Neurobiological Components of Sexual Identity Development and Epigenetic Effects of Environmental Stressors

In this review, we explore the intricate development of sexual identity, drawing insights from genetic, endocrinological, neuroanatomical, and neurophysiological studies. Gender identity, encapsulating an individual's internal perception as male or female, undergoes a nuanced and gradual formation, commencing early in life and progressing through distinct stages. Gender nonconformity delineates behaviors that diverge from culturally prescribed norms, while gender dysphoria encompasses the emotional distress experienced by some individuals due to a mismatch between their gender identity and assigned sex at birth. The genesis of sexual identity involves multifaceted processes spanning numerous years. Human sex differentiation involves the suppression or inactivation of specific genes, a phenomenon illuminated by genetic investigations into gender dysphoria, which have shown comparable rates of genetic variations to the general population. Nevertheless, twin studies suggest an augmented likelihood of transsexuality among family members, hinting at potential environmental influences. Brain sexual differentiation occurs during mid-to-late pregnancy due to the impact of gonadal hormones. The mechanisms underpinning the loss of feminine brain characteristics and subsequent masculinization likely involve a combination of factors, indicating a complex interplay rather than a singular cause. Studies propose that human sexual behavior is not governed by a solitary gene but rather by a network of genes dispersed across the genome. Notably, disparities in brain structures, functionalities between genders, as well as variations in endocrine and serotonin-dopamine levels, are implicated in the etiology of gender dysphoria, contributing to the understanding of this complex phenomenon situated between genders

AA lokomotifler için faz kaymalı bir DGM doğrultucu tasarımı ve laboratuvar prototipi uygulaması.

This research work is devoted to the design, and prototype implementation of a single-phase, unity power factor, Pulse Width Modulated (PWM) Rectifier for use in traction converters of AC locomotives. The PWM Active Rectifier is supplied from a front-end transformer, with two isolated secondary windings. The associated power stage is composed of two single-phase, H-bridge voltage-source converters, which are interleaved via a common DC link. Interleaved connection of converters is used to reduce the line current total demand distortion on the grid side of the traction transformer, to comply with the IEEE Std. 519-1992. Control techniques and PWM methods used in AC locomotive traction applications are analyzed, compared and digitally implemented on a DSP microcontroller. The design and optimization of this system is achieved on MATLAB/Simulink simulation environment. The performance of the implemented system is tested on a low power laboratory prototype composed of the developed PWM rectifier, and a four-quadrant, frequency-controlled induction motor drive and satisfactory results have been obtained.M.S. - Master of Scienc

GaN Tabanlı Bir Tümleşik Modüler Motor Sürücü (IMMD) Tasarımı ve Geliştirilmesi

Bu projenin amacı, süreceği motor ile tümleşik olan, modüler yapıda ve yeni nesil Galyum Nitrat (GaN) transistörler içeren bir motor sürücü sistemi geliştirmektir. Tümleşik modüler motor sürücü (Integrated modular motor drives, IMMD) teknolojisi, temelde güç yoğunluğunu arttırmak amacıyla, motor ile sürücüyü tek bir pakette entegre eden bir teknolojidir. Elektrik motorlarının günümüzde enerji piyasasının yüzde 45’ini oluşturduğu düşünülürse, elektrik motorları ve sürücülerinde enerji verimi artışının ekonomik ve çevresel anlamda çok büyük faydaları olduğu söylenebilir. Bu nedenle, yüksek verim hedeflenen IMMD uygulamaları son yıllarda popüler bir araştırma konusu haline gelmiştir. Bu proje ile birlikte başlatılmak istenen araştırma ve geliştirme sürecinde gidilmek istenen nihai amaç, hem elektriksel açıdan (güç elektroniği), hem elektromekanik açıdan (motor), hem termal açıdan (soğutucu) hem de mekanik açıdan IMMD sisteminin detaylı modellenmesi ve tüm bu yapıların ortak bir potada birleştirilerek bir eniyileme çalışması yapılmasıdır. Bu proje kapsamında, temel yapıların modellenmesi, benzetim çalışması ile karşılaştırma ve tasarımın yapılması ve bir prototip geliştirilerek elde edilen bulguların doğrulanması hedeflenmektedir. Bunun yanında, proje çıktısı olarak bir IMMD donanımı elde edilmiş olursa, Elektrik Makinaları Laboratuvarı’nda ileride çeşitli araştırma ve geliştirme çalışmalarının test edilmesine olanak sağlanmış olacaktır

Design of a GaN Based Integrated Modular Motor Drive

In this study, design procedure of an Integrated Modular Motor Drive (IMMD) is presented focusing on high power density. The design is based on a permanent magnet synchronous motor (PMSM) and GaN FETs. Fractional slot concentrated windings are used on the stator. Slot/pole combination and winding configuration is selected based on having low cogging torque and high winding factor. An extended motor drive inverter topology is proposed where 2-level voltage source inverters are connected both in series and parallel. Optimum selection of number of modules is discussed and power semiconductor devices are selected based on loss characterization. Optimum DC link capacitor bank is determined and the effect of interleaving is investigated. The performance of the motor is validated with ANSYS/1V1axwell simulations. Motor drive performance is obtained with MATLAB/Simulink simulations. The efficiency of the motor drive is enhanced by 2% compared to a conventional motor drive. An overall system power density over 1 kW/It has been achieved with the proposed series/parallel motor drive configuration having GaN FETs

FEN BİLİMLERİ ENSTİTÜSÜ/LİSANSÜSTÜ TEZ PROJESİ

AA LOKOMOTİF CER SİSTEMLERİ İÇİN DGM AKTİF DOĞRULTUCU TASARIMI VE PROTOTİP UYGULANMAS

Design of an Integrated Modular Motor Drive System

Bu çalışmada, bir Tümleşik Modüler Motor Sürücü (TMMS) sistemi tasarımı gerçekleştirilmiştir. TMMS sistemi için modüler bir kesirli oluklu, konsantre sargılı (FSCW), sabit mıknatıslı senkron motor (PMSM) ile birlikte Galyum Nitrat (GaN) teknolojisine dayalı modüler motor sürücü güç katı tasarımı yapılmıştır. Konvansiyonel sistemlere göre %2’lik verim artışı sağlanmıştır. Tümleşik motor sürücü sistemine uygun DA bara kondansatör seçimi gerçekleştirilmiştir. Interleaving tekniği kullanılarak kondansatör boyutu, sığa ve akım gereksinimi yaklaşık yarı yarıya azaltılmıştır. Tasarlanan sistemin başarımı, MATLAB/Simulink ortamında yapılan benzetim çalışmaları ile elde edilmiştir. TMMS sistemi ile konvansiyonel sistemlerde mümkün olmayan 15 W/cm3’ün üzerinde güç yoğunluğuna ulaşılmıştır.In this study, design of an Integrated Modular Motor Drive (IMMD) System is performed. Design of a modular fractional slot concentrated winding (FSCW) permanent magnet synchronous motor (PMSM) and the modular motor drive power stage is performed which is based on Gallium nitride (GaN) technology. The efficiency of the motor drive is increased by 2% compared to conventional motor drive system. Selection of optimum DC bus capacitor suitable for the IMMD is achieved. DC Link capacitor bank size is reduced to its half in terms of both capacitance and current requirement with the utilization interleaving technique. The performance of the designed system is obtained via the simulations carried on MATLAB/Simulink. Power density values larger than 15 W/cm3 has been achieved with the IMMD system which is not possible for a conventional drive