Analytical modeling of magnetically saturated inductance by Lambert W function

Inductance is one of the most important components in order to make energy conversion in the power converters. The dynamics of power converter are affected by inductance. Therefore, in order to obtain accurate power converter dynamic model, one needs to have accurate inductance model. An inductance value is not always constant as it depends on current. Especially in the saturation region, inductance value decreases when current increases. On the other hand, exact eddy current and hysteresis losses estimation can be obtained with an accurate inductance model. This paper proposes an improved analytical inductance model that considers nonlinear B-H curve of a core material. A nonlinear B-H function is fitted using the Matlab Curve Fitting Toolbox. This function includes magnetic flux density (B) against magnetic field strength (H) variation in the both linear and saturation regions. The magnetic circuit model is obtained using a lumped parameter method and the Lambert W function is used to solve the equation which includes nonlinear core reluctance. In conclusion, a nonlinear analytical inductance model is proposed. © 2017 Journal of Magnetics and The Korean Magnetics Society. All rights reserved

Reduced q axis nonlinear MEC model for single layer IPM

2017 IEEE International Magnetics Conference, INTERMAG 2017 -- 24 April 2017 through 28 April 2017 -- 129920Interior Permanent Magnet machine (IPM) has several advantages such as high power density and wide constant power speed ratio, therefore, it is very popular in electric and hybrid automotive industry. © 2017 IEEE

Control of Variable Flux Reluctance Motor in Field Weakening Region

2021 International Aegean Conference on Electrical Machines and Power Electronics, ACEMP 2021 and 2021 International Conference on Optimization of Electrical and Electronic Equipment, OPTIM 2021 -- 2 September 2021 through 3 September 2021 -- -- 173666In this paper, the operating point of variable flux reluctance motors (VFRMs) using voltage and current limits in the field weakening region is investigated. The voltage and current limits of VFRM, which depend on the current capacity of the inverter and the voltage limit of the inverter, are investigated by using MATLAB/Simulink. The d-axis and q-axis currents are represented using a mathematical model of VFRM. According to the analyses, the control algorithm for VFRMs is investigated in the field weakening region. VFRM can properly operate in the constant power region with this method. The conventional inverter is used to supply required d-axis and q-axis currents to armature windings with the space vector pulse width modulation (SVPWM) technique. The DC/DC converter is used to control field windings. For the validation of the investigated control algorithm, 12 slots, 10 poles VFRM is implemented in MATLAB/Simulink. The simulation results show that the investigated field weakening method for VFRM controls the motor in constant power region and extends the speed range. © 2021 IEEE.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 218E057ACKNOWLEDGMENT This work is being supported by TUBITAK (The Scientific and Technological Research Council of Turkey) under contract number 218E057

Power System Installation Area

Shading analyzer systems are necessary for selecting the most suitable installation site to sustain enough solar power. Afterwards, changes in solar data throughout the year must be evaluated along with the identification of obstructions surrounding the installation site in order to analyze shading effects on productivity of the solar power system. In this study, the shading analysis tools are introduced briefly, and a new and different device is developed and explained to analyze shading effect of the environmental obstruction on the site on which the solar power system will be established. Thus, exposure duration of the PV panels to the sunlight can be measured effectively. The device is explained with an application on the installation area selected as a pilot site, Denizli, in Turkey

Diagnosis of late-onset congenital adrenal hyperplasia in clinical practice: current evaluation

Aim. Aim of the study was to investigate the need to perform the adrenocorticotropic hormone (ACTH) stimulation test by recognizing the importance of a second look at basal serum 17-alpha hydroxyprogesterone (17-OHP) levels and calculating new serum 17-OHP cut-off level

ЗАГРЯЗНЕНИЕ ТЯЖЕЛЫМИ МЕТАЛЛАМИ ДОННЫХ ОСАДКОВ ЗАЛИВА ЧАНДАРЛЫ, ТУРЦИЯ

Донные осадки являются природной летописью изменений среды, и их точная датировка обеспечивает хронологию процесса. В частности, датировка ненарушенного керна с помощью 210Pb является наиболее широко используемым и надежным методом для изучения изменений в экосистемах за последние 100 лет. Также часто для независимого контроля и проверки 210Pb-метода используется 137Cs-метод. Залив Кандарли – один из важнейших индустриальных регионов на побережье Эгейского моря в Турции. Таким образом, целью работы было исследование истории загрязнения тяжелыми металлами и определение их содержания в морских грунтах залива Кандарли (включая бухту Алиага) с помощью хронологии 210Pb и 137Cs. Результаты обеспечивают достоверную картину изменений среды в заливе Кандарли.Sediments are historical natural archive of environmental changes, and accurate sediment dating provides a chronology of these changes. In particular, 210Pb is the most common and reliable method during more than 5 decades, through dating of undisturbed sediment cores, to study ecosystem changes during the last 100 yrs. Meanwhile, it is common practice to use 137Cs as an independent age control to verify 210Pb method. Candarlı Gulf is one of the major industrial regions on the Aegean side of Turkey. Hence the study is dealing with the determination of the sedimentation rates and heavy metal pollution history in the sediments from Candarlı Gulf (including Aliaga Bay) derived from 210Pb and 137Cs chronology. The results were provided a realistic picture of the environmental changes of the Candarli Gulf