Sabit mıknatıslı senkron motorun uzay vektör modülasyonlu doğrudan moment kontrolünün benzetimi

Günümüzde mikroişlemci teknolojisindeki gelişmeler ve güçlü mıknatısların üretilmesine bağlı olarak Sabit Mıknatıslı Senkron Motorların (SMSM) kullanımı giderek artmaktadır. Önceleri endüstriyel sürücü sistemlerde yaygın olarak kullanılan asenkron motorların yerini artık SMSM’ler almıştır. SMSM’ler günümüzde asansörler, çamaşır makineleri, elektrikli araçlar, fanlar, pompalar, otomasyon teknolojileri vb. birçok alanda yaygın bir şekilde kullanılmaktadır. SMSM’lerde vektör kontrol yöntemleri olarak Alan Yönlendirmeli Kontrol ve Doğrudan Moment Kontrolü (DMK) kullanılmaktadır. DMK’da stator akısı ve moment, inverter için uygun bir anahtarlama stratejisinin kullanılması ile doğrudan kontrol edilmektedir. Sürücü sistemlerde DMK’nın kullanılması ile modern sürücü sistemlerden istenen iyi bir dinamik cevap ve esnek bir kontrol yapısı elde edilmektedir. DMK, histerezis ve uzay vektör modülasyonlu olmak üzere iki faklı şekilde gerçekleştirilmektedir. Uzay vektör modülasyonlu DMK yöntemi inverterin sabit anahtarlama frekansında çalışmasına imkân sağlaması nedeniyle yaygın bir şekilde kullanılmaktadır. Bu çalışmada SMSM’nin uzay vektör modülasyonlu DMK’sının Matlab/Simulink benzetimi yapılmış ve elde edilen sonuçlar irdelenmiştir. Benzetim sonuçlarından, uzay vektör modülasyonlu DMK ile kontrol edilen SMSM’nin, modern sürücü sistemlerden istenen geniş bir hız aralığında kararlı çalışma ve değişken yük durumları için hızlı moment cevabına sahip olduğu görülmektedir.In parallel to the recent developments in microprocessors technology and production of strong magnets the interest on Permanent Magnet Syncronous Motors (PMSM) increases continuously. PMSM are begun to be used in industrial driver set ups instead of asynchronous motors which were used commonly before. Today PMSM are used in different applications such as elevators, washing machines, electrical vehicles, fans, pumps and automation technologies. In PMSM, Field Oriented Control and Direct Torque Control (DTC) are used as vector control methods. In DTC, stator flux and torque are directly controlled using a suitable switching strategy for the inverter. With the use DTC in driver systems, a better dynamic response and a flexible control which are expected in modern driver systems is obtained. DTC is realized in two ways namely hysteresis and space vector modulation. DTC method with space vector modulation is commonly used since it gives an opportunity for inverter to work at a constant switching frequency. In this study, the simulation of PMSM’s DTC with space vector modulation is generated with Matlab/Simulink and the results are discussed. According to the simulation results, it is observed that PMSM controlled by DTC with space vector modulation has stable action in a wide speed range which is requested from modern drivers systems and fast torque response for variable load states

Outer Rotor SRM Design for Electric Vehicle without Reducer via Speed-Up Evolutionary Algorithm

Reducers utilized in automotive industry provide motor to run in most effective region and transmission output torque to increase. However, they cause mass and cost to increase and also efficiency to decrease due to mechanical losses. The aim of this study is to design a direct drive motor (outer rotor switched reluctance motor (OR-SRM)) without reducer resulting in enhanced efficiency for electric vehicle (EV). To estimate dimension and electrical parameters of OR-SRM, mathematical equations are originally derived from its geometry. Considering the constraints of package size and outer diameter, all the dimension parameters of the motor are optimized via multi-objective genetic algorithm (MOGA) to get the desired efficiency and torque. In order to validate the results in the proposed approach, OR-SRM is modeled by Maxwell 3D using optimized dimension parameters. In-wheel OR-SRM with 18/12 poles (30 kW) is manufactured to employ it in an EV. Theoretical results are compared to experimental results. It can be concluded that the results are satisfactory

Buzağılarda uzun kemik kırıklarının Ilızarov tekniği ile sağaltım olanaklarının araştırlıması

Bu çalışma Ankara Üniversitesi Veteriner Fakültesi Ortopedi ve Travmatoloji Bilim Dalı Kliniği'ne getirilen 3 adet buzağı üzerinde gerçekleştirildi. 2 olguda parçalı tibia kırığı, bir olguda parçalı metacarpus kırığı saptandı. Olguların belirlenen kırıkları genel anestezi altında Iliz.arov'un sirküler eksternal fikz.asyon sistemi ile sağaltıldılar. Birinci olguda (Olgu no: 1) 150 mm çaplı 3 halkalı, 3 rodlu; 2. olguda 150 mm çaplı proksimal 1. halka 1/2 olmaküzere 3 halkalı, 3 rodlu ve 3. olguda proksimal halka 1/2 olmak üzere ve buna hibrid fikz.asyon amacı ile iki adet 4 numara Schanz vidası ile 3 halkalı, 3 rodlu tliz.arov'un sirküler eksternal fıkzasyon sistemi uygulandı. Olguların apareyi çok iyi talere ettikleri ve reaksiyon göstermedikleri belirlendi. Olgular ekstremitelerini ilk kullanmaya sırasıyla postoperatif 2, 6 ve 5. günlerde başlarken, vücut ağırlıklarını ise postoperatif sırasıyla 15, 20 ve 17. günlerde ekstremitelerine vermeye başladılar. Radyografik takipler sonucunda kırık konsolüdasyonunun olgularda postoperatif sırasıyla 45, 35 ve 48. günlerde tamamlandığı izlendi. Olgulardan aparey sırasıyla postoperatif 60, 45 ve 60. günlerde anestezi uygulanmadan çıkarıldı. Bir olguda (Olgu no:3) pin dibi enfeksiyonu izlenirken, başka bir problem olmadan tüm olgularda tam fonksiyonel iyileşme sağlandı. Sonuç olarak Türkiye'de ilk kez buzağıların uzun kemik kırıklarının sağaltımında Iliz.arov'un sirküler eksternal fikzasyon sistemi kullanıldı ve alınan sonuçlara dayanarak bu sistemin buzağılarda güvenle kullanılabilecek bir sistem olduğu kanısına varıld

A survey on comparison of electric motor types and drives used for electric vehicles

In this study, Switched Reluctance Motor (SRM), Induction Motor (IM), Brushless DC Motor, and Permanent Magnet Motor (PM), and their drives have been compared with the efficiency, cost, weight, cooling, maximum speed, reliability, fault tolerance, power ratings, and vehicle acceleration time. Hence, a comprehensive literature research on motor types and their drives used in EV has been made. According to these researches, some conclusions have been obtained. It has been seen that PM BLDC motors and their drives are the most efficient and have high power density, brushless DC motors and their drives have low cost, IM is appropriate for controllability and cost, the weight of SRM is low, its reliability is high, it operates fault-tolerance and according to the acceleration time, its performance is better than IM and BLDC. Hence, SRM is the most appropriate motor for EV

An effective variable selection algorithm for aggressive/calm driving detection via can bus

In this research, the aim is to come up with an algorithm determining most appropriate variables of CAN (Controller Area Network) bus data for Aggressive/Calm Driving detection problem. This study assists drivers to take attention their Aggressive/Calm Driving habits on steering wheel. System complexity increases as involving all the variables in the problem. Therefore we can get cost efficiency by eliminating variables. With this aim, the proposed algorithm is applied to find optimal variables before identifying driving mood. As an initial phase, we have realized several test-drives having employed drivers with different driving styles being aggressive and calm in order for collecting data needed. Afterwards the novel algorithm developed is applied to eliminate trivial variables. Proposed method is based on exploiting similar correlation characteristics related to variables appearing in both Aggressive and Calm driving. As applying the selection algorithm, similar relation clusters are obtained with the aim of searching for redundant variables that will be eliminated. In this manner we reach a favorable set belonging to optimal variables. This novel algorithm can be easily applied for the systems including binary data set

Road geometry based risk estimation model for horizontal curves

Rural roads present potential risks for drivers. One of them is horizontal curve, which poses higher risk than freeway. This is the major theme for the presented work here aiming to develop a model that predicts risk of curved roads. Major road geometry components associated with curve structure are road slope type being uphill or downhill, road curvature, and curve direction along with vehicle speed as being a critical factor. In this study, cameras mounted in rear and front ends of a vehicle that capture road images are utilized to detect the components emerging risk. This two-view approach is exploited to obtain vehicle speed and bend slope type, whereas curve direction and road curvature are determined by single-view front camera. The proposed approach is leveraged by geometrical derivations using salient visual clues such as vanishing points and road boundary. Additionally, velocity is estimated by reverse-view technique, that is, plane of front view at instance t and the plane of rear view in t+1. Subsequently, overall potential hazard is predicted by assigning weights for each risk components via developed risk estimation model. The proposed model would be an integral part of an advanced driver assistant system by alerting driver about the prominent risk of horizontal curve ahead of time

Electronic differential system for an electric vehicle with In-wheel motor

This paper presents modeling and simulation of Electronic Differential System (EDS) for the dual-front-wheel independently driven Electric Vehicle (EV). Electronic differential is utilized in EVs due to some drawbacks of traditional mechanical differential such as being heavy and bulky systems which are not convenient for EV, and mechanical losses caused by the powertrains. In this study, an EDS for front wheels of an EV with in-wheel motor is modelled instead of rare wheels which has commonly been studied in the literature. The front wheel speeds are estimated by equations derived from Ackermann-Jeantand model using Codesys Software Package. Then, the simulation of EDS is also realized by Matlab/Simulink. According to the change of the vehicle speed and steering angle of EV, front wheel speeds estimated by Codesys are verified by Simulink results. It is observed that the modelled EDS is appropriate for EVs with in-wheel motors

Interactive risky behavior model for 3-car overtaking scenario using joint bayesian network

In this paper, we propose a new model for 3-car interactive risky behavior of vehicles travelling in front and behind of a driver (overtaken) car. Following distance of vehicles moving in front and at rear end of the car in question plays an important role for overtaking scenario. Moreover, the distance between the car in front and the vehicle following it should be sufficiently long for preventing collision if overtaking is inevitable for the motorist behind the middle subject vehicle. Here, we consider the roles of the vehicles involved in such a scenario. We observe the behaviors of moving vehicles in front and the rear end of the subject car. To this end, front and rear car images are acquired by two cameras and subjected to vertical and horizontal optical flow edge map creation. In classification stage of the optical flow edge map clusters, a motion vector histogram thresholding method is utilized in conjunction with a decision assessment strategy based on the joint Bayesian belief network statistical model. In turn, not only the trajectories of the cars are captured but also joint behavior of three cars over-taken scenario is estimated using the proposed interactive risk model