Elektrikle tahrik edilen gemi modelinin geliştirilmesi
Development of the electric ship propulsion model
Yazar: MEHMET ERDOĞAN
Danışman: DOÇ. DR. ÖZGÜR ÜSTÜN
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Elektrik Mühendisliği Ana Bilim Dalı
Derece: Yüksek Lisans, 2017
Konu: Elektrik ve Elektronik Mühendisliği = Electrical and Electronics Engineering

Özet:
Enerji tasarrufunun ve çevreye olan duyarlılığının öneminin giderek daha fazla anlaşıldığı günümüzde, hava kirliliğinin azalmasına, yakıt tüketiminin azalmasına ve ithal edilen yakıtların bağımlılığın azalmasına katkıda bulunan elektrikli taşıtlar, konvansiyonel içten yanmalı motorlu taşıtlara bir alternatif olma yönünde olumlu şekilde ilerlemektedirler.
90'lı yılların sonundan bu yana elektrikli taşıtlar piyasada artarak ve gelişerek yer almıştır. Yalnızca batarya veya yakıt pillerinden beslenen elektrikli taşıtlarının maliyetlerinin yüksek olması, uzun şarj süreleri ve kısa menzilleri, ayrıca yakıt pillerinin verim problemleri, hidrojenin depolanmasının zorluğu gibi sebepler yüzünden üretimde karma taşıtlar tercih edilmektedir.
Bu çalışmada yapılmakta olan katamaran tipi karma bir elektrikli geminin bilgisayar ortamında modelinin oluşturulması hedeflenmiştir. Bu modelin kapsamı batarya modeli, elektrik motoru modeli ve gemi modelinden oluşmaktadır. Bu çalışma sırasında en uygun elektrik motoru tipi belirlenmesi ve seçimi, batarya seçimi gibi konularda destek sağlanmış ve bunun için araştırmalar yapılmıştır. İlerleyen aşamalarda fırçasız doğru akım motoru ve kurşun asit batarya tipi belirmiş olduğu için modelleme de bu seçimler üzerinden ilerlemiştir. 
İkinci bölümde, karma elektrikli taşıtlar hakkında genel bilgiler verilmiş ve avantajları üzerinde durulmuştur. Ayrıca karma elektrikli taşıt konfigürasyonları ve özellikleri hakkında bilgiler verilmiştir.
Üçüncü bölümde gemi modeli hakkında genel bilgiler sunulmuştur. Geminin yük direnci oluşturulurken bu bölümdeki bilgilerden yararlanılmıştır. Gemi sevkinde tüm kuvvetlerin bulunması gemi modelini oluşturmasını sağlar. Gemi modelinin oluşturulması genel olarak iki başlıktan oluşmaktadır. Pervane, motordan gelen gücün geminde yarattığı itme kuvvetinin elde edilmesinde ve gemi dinamiği, bu itme kuvvetinin gemide yarattığı hızın bulunmasında kullanılır. 
Dördüncü bölümde, elektrik tahrikindeki alt bölümler incelenmiştir. İlk olarak batarya sistemleri tanıtılmış, batarya karakteristiği ve eşdeğer devreleri hakkında bilgiler verilmiştir. Güç elektroniği kısmında motor kontrolü için yapılan sürme devreleri ve çalışma mantığı anlatılmıştır. Son olarak da elektrik motoru hakkında bilgiler sunulmuş, matematiksel modellemesi yapılmıştır. 
Beşinci bölümde, Matlab Simulink'de yapılan model detaylarıyla anlatılmıştır. Batarya modeli, elektrik motoru modeli ve gemi modelinden oluşan bir sistem halinde sunulmuştur. Bu sistem parçalarının oluşturulurken izlenen yol ve model oluşturulurken yapılan matematiksel hesaplamalar verilmiştir. 
Altıncı bölümde, modelin simülasyon sonuçları ve grafikleri bulunmaktadır. Bu grafikler üzerinden inceleme ve çıkarımlar yapılmıştır. Yapılmakta olan gemi için optimizasyon hesaplamaları, kontrol yöntemlerinin geliştirmesini sağlanmıştır. 
Yedinci bölümde ise elde edilen sonuçlar yorumlanmış ve geleceğe dair çıkarımlar yapılmaya çalışılmıştır.

Abstract:
As the importance of the energy saving and the sensitivity towards environment significantly increases today, electric vehicles, which contribute to reduced air pollution, fuel consumption and dependence on imported fuels, are advancing positively as alternatives to conventional internal combustion engine vehicles.
Since the end of the '90s, electric vehicles have increased and developed in the market. Before that hybrid vehicles are not preferred in production because of the high cost of electric vehicles, powered only from batteries or fuel packs, long charging times, short distances, fuel cell efficiency problems and difficulty in storing hydrogen.
Today's propulsion systems consist of where combustion engines are used. Such systems have the disadvantages of releasing harmful gases and less efficient in energy consumption. These reasons lead to the development of alternative propulsion systems in vehicles. In recent years, technological improvements in power electronic components, motor control units and electrical energy storage systems have made electric propulsions even more usefull. Weight and volume reduction, the flexibility, which are the result of the ease of electrical connection, and improved control capability to make these types of propulsion available in vehicles, has significantly increased the efficiency of the electric propulsions.
In this research, advantages of the Hybrid type electrified vehicles against the conventional internal combustion engine vehicles have been studied. Battery systems, electric motors and the power electronics have been briefly discussed as well as explained in detail as the subdivisions of the electric propulsion systems. The improvements in performance of energy storage elements are the most important factor in extending the driving range of hybrid type vehicles. Although, some researches on various types of batteries continue, it is not hard to foresee that the increase in efficiency is just in near future. Recently produced batteries advantage is that the energy density is high and light weight. However, lead acid batteries also may be preferred in systems where weight can be tolerated to a certain extent, because of seated system and lack of security problems, especially sea transportation. It has been used for a long time and has become a technology that brings these batteries to an advantageous position. In electrical propulsion systems, permanent magnet motors has high power densities and high speed, on the other hand asynchronous motors also offer impressive solutions to meet the growing power needs of hybrid electric vehicles with its mature technology.
In this study, it is aimed to create a computerized model of a catamaran type hybrid electric ship. The scope of this model consists of battery model, electric motor model and ship model. Each section was modeled separately and presented as a system. Achieved results in the form of improved system operation. All these models are created in Matlab Simulink. During this study, support was provided for the selection of the most appropriate type of electric motor, battery types and so on. As the brushless DC motor and lead acid battery type appeared in the following stages, the modeling also advanced through these selections.
In the first section, the differant studies were examined and presented as a literature review. At the beginning of this section, general information about the thesis was given. Afterwards, all article and studies that related to this topic has been analyzed and described in detail.    
In the second part, general information about hybrid electric vehicles is given and its advantages are emphasized. A hybrid electric vehicle (HEV) is a type of hybrid vehicle and electric vehicle that combines a conventional internal combustion engine (ICE) system with an electric propulsion (hybrid vehicle drivetrain). The presence of the electric powertrain is intended to achieve either better fuel economy than a conventional vehicle or better performance. Hybrid electric vehicles has classified according to the way in which power is supplied to the drivetrain. These configurations are serial hybrids, paralel hybrids and serial-paralel hybrids. In series hybrids, only the electric motor propulsions the drivetrain, and a smaller ICE works as a generator to power the electric motor or to recharge the batteries. In parallel hybrids, the ICE and the electric motor are both connected to the mechanical transmission and can simultaneously transmit power to propulsion, usually through a conventional transmission. Serial-paralel hybrids have the benefits of a combination of series and parallel characteristics. This part also provides information on hybrid electric vehicle configurations and features.
In the third part, general information about ship model is presented. The information in this section has been utilized when building the load resistors of the ship. The presence of all external forces in the ship allows the ship model to be formed. The creation of the ship model generally consists of two parts. The propeller is used to obtain the thrust generated by ship's motor. The motor speed and the speed of the ship combined to find ship advance number. The thrust coefficient and the torque coefficient, which depend on this advance number, are calculated. Through these coefficients, torque and thrust are obtained. Ship dynamics are used to find the speed created by this thrust. Afterwards, all these terms are explained in this section to find the ship speed.
In the fourth chapter, the subdivisions in the electric propulsion are examined. In electric vehicles, the energy required to turn the motor is stored in the battery. For this reason, the batteries are vital for electric vehicles and a wide variety of batteries are used for this purpose. Lead acid batteries, Ni-MH batteries and lithium batteries are the most commonly used ones. In that rechargeable batteries, lead acid batteries has the largest share in the market. The reason for this battery is that the cost of the basic elements (lead, sulfuric acid, plastic housing) is low, it functions safely and it has a very high voltage per battery cell. The battery systems are introduced, information about battery characteristics and equivalent circuits are given. 
In the power electronics section, the driving circuits and the operating logic for motor control are described. Usually the BLDC motor control system consists of two parts: hardware and software. The hardware section consists of a main circuit, a drive circuit, a microprocessor control circuit and a protection circuit. The software part contains the main program, a timer interrupt subroutine. In this section, engine control and power electronics part is analyzed. The motors used in electric vehicles can be catogorized in four basic groups which are direct current motors, asynchronous motors, permanent magnet synchronous motors (brushless direct current motors) and switched reluctance motors. Brushless DC motors (BLDC) can be used in many cases in place of standard DC motors. DC voltage is applied and the commutating is done by electronic switching. The commutating is done with or without sensors, depending on the rotor position. BLDC motors have many advantages over conventional DC motors. That issues about the electric motor was presented and mathematical modeling was done.
In the fifth chapter, the model in Matlab Simulink is explained in a detailed manner. The battery model, electric motor model and ship model are presented as a whole system. The battery model is prepared based on the characteristics of the selected battery. Since the electric motors operate at 48V, four 12V batteries connected in series. The motor model is based on the brushless direct current motor which was selected. This engine is in 10kW power and works with 48V direct current. The operation of the BLDC motors is characteristically the same as the operation of the brush DC motors. In BLDC engines, the speed range varies according to speed, engine size and speed / load capacity of the engine. BLDC motors are preferred because they have a high maximum moment of inertia and have a speed, accuracy, and long-term stability. For this reason, speed control is very important. The maximum speed (idle) of the engine used for the ship is given as 5000 rpm. There is a varying speed graph depending on the load.
In the sixth section, there are simulation results and graphics of the model. Examination and deduction were done through these graphs. Optimization calculations for the ship under construction have been developed to improve the control methods.
In the seventh chapter, the results obtained are interpreted and the conclusions about the future are tried to be anticipated.
Within the scope of this thesis, it is planned to construct a catamaran type ship driven by electricity, with the cooperation of ITU and Teknokent. In this context, the shipbuilding department and the electrical department were investigated and the physical characteristics of the ship were revealed. In line with this information, the necessary engine power is provided for the desired ship speed. After that, the types of electric motors were examined and decided on the Golden Motor BLDC engine. Once this engine is supplied, the motor characteristics are calculated by inserting it into the motor tests. It is aimed to predict the performance that will occur during ship loading during motor tests. Since this engine is water-cooled, the heat exchanger system has been designed and made suitable for the ship. Sea water will cool the water which is circulating in the engine. After this system is installed and integrated into the motor, the battery systems for the motors are examined and their suitability investigated. As a result of these investigations, lead acid batteries were selected. Despite the fact that the energy intensity is not very high, it is an advanced technology. The capacity is selected according to the working time in the electric mode. The results of these selected motor features and calculations are used in the Matlab Simulink to prepare the electric motor model. A battery model has been created with battery characteristics and working characteristics. At the beginning of the surveys, ship physical model and ship load model were obtained and all the system was composed of these three models. The ship's load model is intended to give approximate values of the load model results as much as possible that calculated as mathematical calculations and empirical values. The methods used when preparing the model are also included in this thesis. Then, model results and generated graphs were examined and interpretations and conclusions were made in the direction of these results.
As a result, all of these performed test and model results have been used to determine the working characteristics of the ship and the issues that will occur in the following phases have been tried to be predicted.