عنوان رویداد:
دانشگاه حکیم سبزواری
تاریخ برگزاری : 10 اسفند 1401
The demand for lightweight converters with high control performance and low acoustic noise, increased the switching frequencies of two-level low-voltage 3-phase converters over the last few years. For high switching frequencies, converter efficiency suffers and can be kept high only by employing cost-intensive switch technology such as SiC diodes or CoolMOS switches; therefore, و...
در این تحقیق، یک مطالعه شبیه سازی طراحی ساختار بهینه برای استاتور ژنراتور ورنیر روتور خارجی با آهنربا از نوع اسپوک، به منظور بهبود عملکرد کاربردهای مختلف مانند برخی از لوازم برقی خانگی و اکثر تجهیزات انرژی جدید مانند توربین های بادی مورد بررسی و مقایسه قرار گرفته است. در این مقاله طول دندان استاتور، عمق شکاف استاتور، فاصله بین دو شیار استاتور، ارتفاع باز شدن شیار به عنوان متغیر و...
از جمله خطا های رایج در موتور های القایی، خطای ناهم محوری است که تشخیص به موقع خطا به منظور پیشگیری از گسترش آن از اهمیت بالایی برخوردار است. یکی از رایجترین روشها برای تشخیص ناهممرکزی، تحلیل طیف جریان استاتور موتور (MCSA ) می باشد که تحلیل فوریه (FFT) از ساده ترین روشها برای پیاده سازی MCSA میباشد. در این مقاله مدل دقیقی از ماشین در شرایط سالم و معیوب با نرم افزار MAXWELL ا و...
Electric vehicles offer an unmatched experience thanks to their torque profiles. They must be optimized when considering intracity driving cycles (frequent start-stop) by dealing sensitively with the efficiency/performance relationship. Asynchronous motors are commonly used in electric vehicles. Parameters like stator/rotor geometry, number of slots, and materials used are incr و...
High voltage converters are commonly used in various applications, namely, PFC, HVDC, water treatment, and high-voltage dc power supplies. This paper proposes a high-voltage output DC-DC LLC resonant converter, which provides some good features such as soft switching leading to low electromagnetic interference, that can enable the opportunity to achieve higher efficiency and hi و...
خلاصه امروزه موتورهای القایی (IM) به طور گسترده مورد استفاده قرار می گیرند و تعمیر و نگهداری آنها مورد توجه زیادی قرار گرفته است. احتمال بروز عیب در یاتاقان و سیم پیچ استاتور در این موتورها زیاد است. این مقاله روشی را برای تشخیص خطای بلبرینگ (BF) و خطای سیم پیچ استاتور (SWF) در IM با استفاده از تحلیل امضای جریان موتور (MCSA)، مقدار RMS فعلی، فیلتر وینر و تبدیل موجک تجربی (EWT) و...
در این مقاله دو نوع موتور خطی سوئیچ فلاکس که هرکدام در دو ساختار متفاوت ارائه شده اند بررسی و عملکرد آنها آنالیز شده است. در یک نوع میدان از طریق سیمپیچی و در نوع دیگر میدان از طریق ماده مغناطیس دائم(آهنربا) تامین میشود. در هریک از این دو نوع مذکور دو ساختار متفاوت از نظر ترکیب دندانههای رتور و استاتور امکان پذیر است که به اختصار 10/12 و 14/12 نامگذاری میشوند. در این مقال و...
Consequent-pole Permanent Magnet (CPM) machines have been widely proposed due to the high Permanent Magnet (PM) utilization ratio. However, CPM machines suffer from asymmetrical air gap flux density due to using PMs with the same polarity, which causes high torque ripple and asymmetrical back Electro Motive Force (EMF) voltage. So, the purpose of this paper is to present a new و...
In this paper, a dual active bridge converter based on the utilization of two transformers is presented. Also, the principles of operation, switching strategy, and transmission power characteristics of the proposed converter are discussed. Moreover, the RMS current of two transformers with different values of inductances of the inductors that are in series with the transformers و...
In this paper, a method for Zero Crossing Point (ZCP) error correction to improve commutation accuracy, called Index Pulse Comparison (IPC), is proposed. Firstly, Brushless Direct Current (BLDC) motor is mathematically modeled and voltage and torque equations are extracted. Then, the twelve-pulse production strategy, which includes the creation of two types of pulses, is introd و...
The conventional direct torque control (DTC ) method suffers a flux drop at low speeds, which is due to the long selection of zero (neutral) voltage vectors in these speed areas. Past studies with the continuous switch of direct and reverse active vectors to achieve proper flux adjustment, this procedure causes high and consecutive overshoots in the hysteresis band that causes و...
The torque density of multiphase machines with a prime number of phases (five and seven) has been found to be superior compared to machines with other phase numbers. However, these machines need a unique stator design. Hence, either the manufacturing process of electric machine should be change or the three-phase machines should be upgraded to multiphase winding by rewinding te و...
Encoders are the most common speed/position sensors in industrial applications. The commercial encoders are divided into two groups: optical and magnetic types. From accuracy point of view, the first one has distinguished performance. While, the next has superior performance in harsh environments. The accuracy of the magnetic encoders is influenced by geometrical dimensions of و...
Nowadays, Interior Permanent Magnet Synchronous Motors (IPMSMs) are taken into attention in the industry owing to their advantages. Moreover, in many cases, performing static tests is not enough, and investigating electric machines under dynamic conditions is necessary. Accordingly, by employing a dynamometer system, the dynamic behavior of the electric machine under test is in و...
The main problem in the BLDC motor drive is high torque ripple. One reason for the torque ripple in this motors is the commutation torque ripple. An efficient method to reduce the commutation torque ripple is PWM-MPC . This method reduces the non-commutation phase current ripple by changing the duty cycle of the incoming and outgoing phase current path switches in the commutat و...
Renewable energy has been the topic of much research over the years. Wind power generation, categorized as a direct drive application, requires a low-speed and high-power density generator. The permanent magnet Vernier machine is one of the flux modulation ones which can have both features simultaneously. The axial flux structure can be a better solution for this application in و...
In this paper, the dual-rotor dual-stator axial field flux-switching PM (DR-DS-AFFSPM) topology is presented, designed, and analyzed to improve the cogging torque and torque ripple. The 12-pole dual-stator has been located on both sides of the 10-pole internal dual-rotor and phase-group concentrated-coil windings for the aim of increasing fault-tolerant capabilities. The 3D fin و...
Water coolers are one of the household appliances that have remained in their original form since they became popular, and few changes have been made. This high consumption device, which is widely used in Iran due to weather conditions, needs changes to improve its performance and efficiency, which has received little attention in recent years. Among its changes, we can mention و...
In this article, the calculation of momentary electromagnetic torque in a brushless shaft permanent magnet motor has been done using Lorentz force theory. In this method, the anti-motor voltage and phase current are used and a new method for calculating the different harmonics of the anti-motor voltage has been presented using an analytical method. The results of the presented و...
The induction motor (IM) is by far, the most used motor type in the industry, especially for fixed-speed line-start applications. But, due to the rotor slip and joule losses of the rotor cage, IM hardly reaches high-efficiency classes. A good candidate instead of IM to reach higher efficiency classes is the line-start synchronous reluctance motor (LS-SynRM). The main design cha و...
Using the structure of the dual-parallel motors fed by mono-inverter is developing in electric trains and cars for reasons such as managing energy consumption and reducing the volume, weight, and cost of electric motor drives. The major problem in this structure, also called Mono-Inverter Dual Parallel (MIDP), is the design of the current controller in the unequal load torque c و...
ژنراتورهای سنکرون بدون جاروبک بواسطه قابلیت اطمینان بالا و نیاز کم به تعمیر و نگهداری در بسیاری کاربردها مورد استفاده قرار می گیرند. در سیستم تحریک بدون جاروبک اندازه گیری ولتاژ و جریان تحریک ژنراتور اصلی امکان پذیر نیست و لذا تخمین این کمیت ها در مواردی چون پایش وضعیت و تشخیص خطا، تخمین پارامتر، کنترل و حفاظت از اهمیت ویژه ای برخوردار است. در این مقاله دو روش برای تخمین جریان و...
روش تحلیل پاسخ فرکانسی یک روش جدید تشخیص خطا در ترانسفورماتورها و موتورهای القایی سه فاز میباشد. این روش قادر به تشخیص خطاهای رایج در موتورهای القایی نظیر خطای سیمپیچی میباشد. این مقاله، از روش ذکر شده برای تشخیص خطای سیمپیچی استاتور موتورهای القایی سه فاز اعم از خطای اتصال کوتاه کلاف به کلاف و خطای اتصال کوتاه فاز به فاز استفاده میکند و وضعیت موتور را در حالات سالم بودن و...
Nowadays, Permanent Magnet (PM) motors are taken into attention and are widely used in various systems with high-efficiency concerns. In elevator systems, a direct connection is between fault tolerability and human lives, so reliability and lifetime management are significant concerns. The electric motor is the core of traction in the elevator. Although Induction Motors (IMs) a و...
In this paper, a new topology of fractional slot concentrated winding double rotor axial flux permanent magnet synchronous motor (FSCW-DRAFPMSM) is introduced. The desired structure consists of a non-slotted stator core and two rotor discs. The pole number of the two rotors is different and these two rotors rotate at different speeds in opposite directions. A sample motor with و...
ریزالوها از جمله مهمترین حسگرهای تعیین موقعیت هستند که به منظور تعیین موقعیت در حرکت چرخشی و خطی مورد استفاده قرار میگیرند. در ریزالورهای خطی وجود اثر انتهایی طولی و عرضی منجر به کاهش دقت در اندازهگیری موقعیت میشود. از این رو استفاده از روشهای جبران این اثرات ناخواسته به منظور کاهش خطا، از اهمیت زیادی برخوردار است. استفاده از ساختار لوله ای در مقایسه با ساختار مسطح، منجر و...
Torque and rotational speed scaling is a typical requirement of industry for a variety of applications. Magnetic gears benefit from numerous advantages due to their physically isolated rotors. Gearing action in magnetic gears occurs by the interaction of the modulated magnetic fields through modulators. The finite element method is typically utilized throughout the design proce و...
Because of robust rotor structure, switched reluctance motor (SRM) can be a good candidate for high-speed applications. Due to high centrifugal forces at high-speed, structural analysis of the rotor core in an indispensable part of the design. In this paper, a 4kW-3000rpm SRM is considered. The maximum speed of the case-study motor is 7000rpm. The aim is structural and failure و...
This work discusses the performance of the predictive functional control (PFC) approach by utilizing two well-known observers as disturbance estimators for permanent magnet synchronous motors (PMSMs), which are frequently characterized by nonlinearity and uncertainty. PFC serves as a link between complicated model predictive control (MPC) and PI(D)-based control. PFC is a simpl و...
This paper discusses the equivalent circuit of doubly fed induction machine in relevance to reactive power flow from the rotor. In particular, consistency of the traditional circuit model at super-synchronous speed is studied. It is proven that, while the existing model is valid for all rotor speeds, care is necessary when expressing rotor reactive power using the steady-state و...
Dynamometers are widely used for electric machines and their drive systems assessment, reducing prototyping time for many applications, such as Electric Vehicles machines. Having the same mechanical topology allows changing the control algorithm to significantly improve the overall functionality. Hence, this paper proposes dynamic load emulation by utilizing sliding mode contro و...
در این مقاله روشی برای کنترل بدون حسگر مکانیکی برای موتورهای جریان مستقیم بدون جاروبک با استفاده از دوازده پالس شاخص ارائه شده است. ابتدا، موتور BLDC به صورت ریاضی مدل سازی گردیده و معادلات ولتاژ و گشتاور استخراج شده است. سپس، روش تولید دوازده پالس که شامل پالس شاخص و کموتاسیون است، توضیح داده شده و مقدار سرعت و فاصله زمانی بین هر پالس محاسبه شده است. در آخر با استفاده از پا و...
This paper presents an equivalent circuit of the single-phase asymmetric induction machine based on the VBR (Voltage Behind Reactance) model, which is a Thèvenin equivalent, valid in transient and steady-state conditions. This model allows the electromechanical converter to be represented in circuit calculation programs such as Simulink, Proteus, PSIM or ATP-EMT, among others. و...
In dynamic-drive tests on electric motors, the dynamometer has a key role. An AC dynamometer has advantages such as higher dynamics, efficiency, and reliability among the other categories like eddy current brake. Since the accuracy of measurement in dynamic tests has a high dependency on the AC dynamometer s operating condition, proposing an electric motor with advantages inclu و...
در این مقاله به بهبود ساختار قطب روتور به منظور کاهش گشتاور دندانه ای موتور شار محور شار سوئیچینگ مغناطیس دائم پرداخته می شود. روش ارائه شده در این مقاله مشتمل بر دو تکنیک آنالیز ضریب کمان قطب روتور و تکنیک زاویه شکل دهی قطب روتور می باشد. غالب روش های ارائه شده برای کاهش گشتاور دندانه ای موتور شار محور شارسوئیچینگ مغناطیس دائم، موجب کاهش گشتاور الکترومغناطیسی موتور نیز می شوند و...
The evaluation and laboratory study of the electrical machines and their drive system can guarantee an optimum design and utilization of electrical drives in many industrial and research-based applications. Therefore, the testing standards and their required equipment are provided from the beginning of electrical motors commercialization. Using a mechanical load emulator is man و...
A new type of Dual Stator Permanent Magnet (DSPM) machine, which is capable of producing high torque at low operating speed, for direct-drive applications is proposed and analyzed in this study. ANSYS-MAXWELL-2D/3D computational software is employed in the prediction of the machine performances, using the finite element technique. The considered machine performance indices are و...
Currently, switched reluctance machines (SRMs) have attracted the attention of the research community for electric vehicle (EV) applications due to their good performance at high speeds. This paper presents a new converter that doubles the negative demagnetization voltage for EV applications, so that, the provided converter is capable of reducing demagnetization time considerab و...
Abstract: In hybrid vehicles, the electric motor and the combustion engine work as complements. In choosing the electric motor, the simplicity, cheap price, robustness and stability of the motor are considered, so the reluctance switch machine (SRM) is one of the best options. the beating heart of hybrid and electric vehicles is their drive, which is responsible for transferrin و...
In recent years, multilevel converters have received significant consideration as power-conversion systems for demanding applications requiring high power and power quality. Furthermore, Pulse-width sequences have been recognized as the primary defining factor of common-mode voltage (CMV), which through parasitic capacitances, generate bearing currents and shaft voltages, which و...
During conversation energy by electric machines, some energy will inevitably be wasted in the form of losses. The machine losses will be converted into heat and will increase the temperature of the machine components. Due to the dependence of electrical and mechanical properties of materials on temperature, investigating the heat transfer process in electric machines is imperat و...
Coreless Permanent Magnet machines are increasingly used in many industrial applications, such as automotive and aerospace applications, wind turbines, medical equipment, robotics, servo drives, etc. In coreless PMDC machines, the rotor has a coreless winding structure and due to the absence of iron core, the permanent magnet plays significant role in these machines. Also, the و...
Direct drive applications have become one of the most exciting research fields recently. Using the modulation effect (already known as the gearing effect), these kinds of machines can work at low speeds and have the low volume at the same time. Permanent magnet Vernier machine (PMVM) is one of these machines which have been the topic of papers during recent years. In order to r و...