Hibrit büyük patlama büyük çöküş-nelder mead algoritması kullanarak solar hücre parametre kestirimi
Solar parameter estimation by using hybrid big bang big crunch-nelder mead algorithm
Yazar: ÖMER GÖNÜL
Danışman: DOÇ. DR. OSMAN KAAN EROL
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Mekatronik Mühendisliği Ana Bilim Dalı / Mekatronik Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2018
Konu: Mekatronik Mühendisliği = Mechatronics Engineering
Dizin: Evrimsel algoritmalar = Evolutionary algorithms    ; Güneş enerjisi = Solar energy ; Parametre optimizasyonu = Parameter optimization

Özet:
Dünya genelinde oluşan sosyal, ekonomik ve politik ilişkiler, çevresel bilincin artma hususu, gelişen teknolojiyle birlikte artan enerji talebi ve buna bağlı olarak konvansiyonel enerji kaynağı bulunmayan ülkelerin ekonomilerinin ciddi bir kısmını enerji harcamalarının kapsaması durumu, son yıllarda yenilenebilir enerji kaynaklarına yönelimi artırmıştır. Bununla birlikte uzun vadeli planlamalarda ülkelerin sahip oldukları potansiyeli dikkate alarak, yenilenebilir enerji oranlarında artış görülen stratejiler geliştirilmeye başlanmıştır.
Güneş enerjisi de son yıllarda ilgi odağı haline gelen yenilenebilir enerji kaynaklarından biri konumundadır ve konuyla ilgili birçok araştırma geliştirme faaliyetleri ve yatırım çalışmaları bulunmaktadır.
Kullanım olarak güneş enerjisi sistemlerinde en büyük payı fotovoltaik modüller almaktadır. Yarı iletken malzemelerden meydana gelen modüllerin teorik olarak ulaşabilecekleri belirli verimlilik değerleri bulunmaktadır. Elde edilen verimlilik değerleri ise laboratuvar ortamında değerler olup, çevresel şartlardan, kullanım şeklinden ve başka nedenlerden dolayı daha da aşağı çekilmektedir. Bu nedenlerden dolayı elde edilecek enerji miktarının doğru kestirilmesi, planlamaların daha gerçekçi yapılabilmesi için simülasyon çalışmaları oldukça önem arz etmektedir.
Bu tez çalışmasında da güneş hücrelerini bilgisayar ortamında daha hassas modelleyebilmek için literatürde kullanılan elektrik eşdeğer devre modelleri içerisinde bulunan fakat modül üreticileri tarafından paylaşılmayan parametrelerin kestirimi yapılmıştır.
Birinci bölümde, yenilenebilir enerji kaynaklarından birisi olan güneş enerjisi kullanımının yıllar içerisinde evrilmekte olduğu durum anlatılmış, çalışma kapsamında ortaya koyulan hipotez ve amacı açıklanmış ve bu konuyla ilgili olarak yapılan literatür çalışmalarından bahsedilmiştir.
İkinci bölümde ise, güneş hücrelerini veya modüllerini bilgisayar ortamında kolayca modellemek için kullanılan tek diyot, çift diyot ve üç diyot yapılı elektrik eşdeğer devre modelleri anlatılmıştır. Ayrıca modüllerde kullanılmak üzere, elde edilen bu modeller uyarlanmıştır.
Üçüncü bölümde, çalışmada kullanılmak üzere amaç fonsiyonunun tanımı oluşturulmuş ve kullanılan algoritmanın temelleri verilmiştir. Buna göre ilk olarak yerel aramada başarılı olan Nelder Mead yöntemi, daha sonrasında ise Büyük Patlama Büyük Çöküş algortimasının temel adımları anlatılmıştır. Bölümün sonunda ise bu iki yöntemin çalışmada kullanılan hibrit hali anlatılmıştır.
Simülasyon sonuçlarının paylaşıldığı dördüncü bölümde, literatürde açık olarak paylaşılan veri setleri kullanılarak yapılan simülasyon sonuçları verilmiş ve elde edilen sonuçlar ise literatürde var olan diğer çalışmalarla karşılaştırılmıştır. Çalışmada kullanılan güneş hücresine ait veri setine tek ve çift diyot modelleri uygulanmıştır. Diğer kullanılan iki güneş modülü için ise, tek kristal yapılı olana tek ve çift diyotlu model, çok kristal yapılı olan module ise ek olarak üç diyotlu model için parametre kestirimi uygulanmıştır.
Son bölümde ise, çalışmanın genel özeti paylaşılmış, sonuçlar hakkında yorumlar yapılmış ve gelecekte yapılabilecek çalışmalarla ilgili bilgi verilmiştir.

Abstract:
Social, economic and political relations around the world, increasing environmental awareness, increasing demand for energy along with developing technology and also the fact that energy expenditures cover a significant portion of the economies of some countries which do not have conventional energy resources have increased the tendency to the renewable energy resources in recent years. Nevertheless, taking into account the potential of the countries in long-term planning, strategies have started to be developed which have an increase in renewable energy rates.
Solar energy is one of the renewable energy sources that has become a focus of attention in recent years and there are many research and development activities and investment studies.
The use of photovoltaic modules is the largest share of solar energy systems. Modules which constitute semiconductor materials have specific efficiency values that can be reached theoretically. However, the obtained efficiency values are obtained in the laboratory environment and due to environmental conditions, usage and other reasons, these efficiency values further reduce. For these reasons, simulation studies are very important in order to determine the amount of energy to be obtained and to make plans more realistic. The purpose of simulation operations is to make analysis of return from the system before the installation. In the solar energy systems, the behaviour of the panel to be used must be accurately determined, however photovoltaic panel manufacturers provide information about open-circuit voltage, short-circuit voltage, current at maximum power point, voltage at maximum power point and power at maximum power point. Besides, some manufacturers also present open-circuit voltage temperature coefficient and short-circuit voltage temperature coefficient. These parameter values are usually given under the standart test conditions (1000 W/m2 solar radiation and 25 ⁰C ) and do not include the knowledge and effect of the environmental conditions because the temperature of the panel working under the sun an reach higher than the standart temperature. For this reason, the model of the system should be done in computer in order to make the system simulations more accurate. In other words, the most striking point in the simulations is how closely the photovoltaic cell or module model can respond to the behaviour of the physical system. If data obtained from photovoltaic cells or panels corresponds to the results obtained from the computer, the model can be easily used in solar simulators and more realistic, accurate results can be obtained. In this respect, numerous modeling methods have been developed and tested. Electrical equivalent circuit models are among the most widely used models and they can be transferred to the computer environment and can be simulated easily.
In this thesis, in order to model the solar cells more accurately in computer environment, parameters which are found in electrical equivalent circuit models used in literature but which are not shared by module manufacturers were estimated.
In the first section, the situation in which the use of solar energy has been evolving over the years, the hypothesis and purpose of the study has been explained and the literature studies on this subject have been mentioned.
In the second section, the single diode, double diode and three diode electrical equivalent circuit models which are used to model solar cells or modules in computer environment are described. In the absence of solar radiation, the solar cell behaves like a simple p-n junction diode. On the other hand, in the case of solar radiation, current flows through the circuit. However, this structure is quite ideal and does not reflect real conditions. For instance, there is a contact resistance between the silicon and the electrode surfaces. For this reason, a series resistance is added to the ideal diode model to include more realistic behaviour. Although the single diode with series resistance model improves the ideal single diode model, the accuracy of this model decreases when sudden temperature changes occur. In addition, a parallel resistance was added to the model considering the leakage current losses. By doing this, the accuracy of the model can be increased. The effects of the recombination losses in the depletion region have not been mentioned in the previously studied single diode equivalent circuit models. Considering this loss, a more sensitive solution was needed and therefore a second diode was added to the equivalent circuit. In addition, there is a model with three diodes, this model is not applied to any kind of material structure because it takes into account the particle structure of the material. The quality of multi-crystalline materials is lower than the single-crystalline structures, because the multi-crystalline material has many boundaries in the particle structure and these boundaries block the carriers. Particularly, the formation of boundaries on the material of multi-crystalline photovoltaic cells with large area and these effects are more dominant. To model this effect, a third diode was added to the model.
In the third section, the definition of the objective function is used for the study and the basics of the algorithm used are given. According to this, firstly the basic steps of Nelder Mead method which is successful in the local search and then Big Bang Big Crunch algorithm are explained. At the end of this section, the hybrid form of these two methods is described. In hybridized form, firstly, a random N candidate solution determined for the population. Then, the objective function of each candidate solution is calculated and the best point (the smallest one) is stored. Following to this, the D+1 best point where D is the dimension number is given to the Nelder Mead algorithm. If the new best point obtained from NM has better than the previously stored point, the best point is updated. If not, it is continued with the stored point. Afterthat, a new population around the best point which can be also called center of mass is created. If the maximum number of function evaluation (NFE) is not reached, the algorithm turn back to initial point and the processes continue until the maximum NFE is reached. In this study, the NFE was determined as 10000, 20000 and 30000 for single, double and three diode models respectively. The populations created in algortihm have 10 individuals. In BBBC, the parameter which adjust the explosion strenght set as 1. On the other hand, in NM part the reflection, expansion, contraction and shrinking factors are selected as 1,2,0.5 and 0.5 respectively.
In the fourth section, simulation results are given by using the data sets that are shared in the literature and the obtained results are compared with the other studies in the literature. Single and double diode models were applied to the solar cell (R.T.C. France) data set used in the study. For the other two used solar modules (STM6-40/36 and STP6-120/36), single and double diode models with a single crystal structure and multi-crystalline module are implemented. Additionally, three diode model is performed for multi-crystalline module (STP6-120/36).
In the last section, the general summary of the study was shared, comments were made about the results and information was given about future works.