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The effect of temperature on the nitrification rate in moving bed sequencing batch biofilm systems
Get PDFBu çalışmada hareketli yataklı ardışık kesikli biyofilm reaktörlerinde (HYAKBR) sıcaklığın nitrifikasyon hızı ve maksimum ototrofik çoğalma hızı üzerindeki etkilerinin ortaya konulması amaçlanmıştır. Çalışma kapsamında laboratuar ölçekli bir HYAKBR’de evsel nitelikli sentetik atıksu kullanılarak üç farklı sıcaklıkta (20, 15 ve 10°C) nitrifikasyon hızı ve kinetik katsayılar belirlenmiştir. Nitrifikasyon hızı, sıcaklıktan önemli derecede etkilenmiş, 20°C için 0.241 g NOX-N m-2gün-1 ve 10°C için 0.178 g NOX-N m-2gün-1 değerini almıştır. Aynı etki, maksimum ototrofik çoğalma hızı değerleri üzerinde de görülmüş, 20°C için 0.50 gün-1, 15°C için 0.32 gün-1 ve 10°C için 0.09 gün-1 olarak elde edilmiştir.Anahtar Kelimeler: Aktif Çamur; biofilm; hareketli yataklı ardışık kesikli biofilm reaktör; nitrifikasyon.This study investigates the effect of temperature on the nitrification rate and the maximum growth rate of an autotrophic biomass sustained in a moving bed sequencing batch biofilm reactor (MBSBBR). This type of a reactor is a novel hybrid system combining the advantages of attached and suspended activated sludge together with sequencing batch reactors. In this system, biofilm grows on small carrier elements that move along with the water in the reactor by aeration (aeration phase) or by mechanical stirring (anoxic/anaerobic phase). Experimental studies were carried out in a lab-scale MBSBBR, receiving a synthetic influent that had domestic wastewater characteristic, and operated at three different temperatures (20, 15, and 10°C). Evaluation of the results revealed that removal of organic matter at high rates and with efficiencies over 90% was secured at all operation conditions applied. Nitrification rate was significantly influenced by changes in temperature, resulting in a decrease from 0.241 g NOX-N m-2d-1 at 20°C to 0.178 g NOX-N m-2d-1 at 10°C. The same influence was observed on maximum autotrophic growth rate; values of 0.50 d-1, 0.32 d-1, and 0.09 d-1 at 20°C, 15°C, and 10°C were obtained, respectively. In the further studies, heterotrophic and autotrophic kinetic constants should be determined for municipal and different industrial wastewaters.Keywords: Activated sludge; biofilm; moving bed sequencing batch biofilm reactor; nitrification
Implementation of adaptive fuzzy logic based methods on parallel active filter systems
Get PDFParalel Aktif Filtreler (PAF), lineer olmayan yüklerin üç fazlı alternatif akım (AA) güç sistemlerinde yarattığı harmonik akım, reaktif güç gibi elektrik enerji kalitesini bozan etkilerini azaltmada oldukça başarılıdır. PAF’nin yük akım kompanzasyon yeteneği, güç yapısında yer alan pasif elemanlar kadar, gerilim ve akım kontrol çevrimlerinde kullanılan kontrol yöntemlerine de bağlıdır. Bu çalışmada PAF sisteminin doğru akım (DA) gerilim kontrol çevriminde kullanılan farklı kontrolörlerin performansları karşılaştırmalı olarak verilmiştir. Klasik Bulanık Mantık temelli PI (BPI) kontrolörünün performansı, kontrol parametrelerinin adaptasyonu ile arttırılabilir. Bu çalışmada, BPI kontrolörünün sadece çıkış ölçeklendirme katsayısının bir kazanç ayar mekanizması yardımıyla adaptasyonu incelenecektir.Anahtar Kelimeler: Paralel aktif filtre, harmonik, güç faktörü, bulanık mantık. Power Electronics based equipment characterised by non-linear and time varying operation are the common sources of current/voltage harmonics and reactive power in electric power systems. To reduce the effects of harmonic currents and reactive power, which significantly degrade the performance and efficiency of the electric power distribution system, three phase Parallel Active Filter (PAF) in which a Current Controlled, Voltage Source PWM IGBT power converter is the core element is connected in parallel with the non-linear load to compensate the load harmonic currents and reactive power drawn from the mains utility. In principle, PAF improves the electric power quality by drawing the same magnitude, but opposite phase harmonic and reactive current components consumed by the non-linear type power electronics loads and keeping the supply currents sinusoidal and in-phase with the related phase voltages. In this paper, classic and Adaptive Fuzzy Logic based PI controllers as well as linear PI controller are employed in the dc voltage control loop and their performances are compared. Two different adaptation methods for scaling factors of fuzzy controllers are studied. It has been found that self tuning adaptive fuzzy logic based controllers perform better than their classic fuzzy logic based counterparts in which input and output scaling factors are constant. Matlab 6.1 software package has been used in simulation studies. Keywords: Parallel active filter, harmonic, power factor, fuzzy logic
Development of a Digital Micromirror (DMDTM) based 3D profilmeter
Get PDFGelişen teknolojilere paralel olarak imal edilen ürünlerin boyutlarının küçülmesi ve yüzey hassasiyetlerinin artıp parçaların daha kırılgan yapıya sahip olmaları, araştırmacıları bilinen standart temaslı ölçme aletlerinin dışında hasarsız ve hızlı yeni ölçme tekniklerini aramaya yönlendirmiştir. Optik ölçme teknikleri de hasarsız ölçme kapasiteleri nedeniyle 1960’lardan başlayarak günümüze kadar büyük bir hızla gelişmiş ve günümüzde hiç tartışmasız mikro teknolojiden bio-teknolojiye birçok alanda temaslı ölçme cihazlarının yerini almıştır. Konfokal mikroskop ise 1960 yılında M. Minsky tarafından geliştirilmiş ve standart mikroskoplara oranla daha hassas ve detaylı ölçme kapasitesi sunması nedeniyle diğer optik ölçme metodları arasından hızla sıyrılmıştır. 1990’larda, Xiao, Corle, ve Kino’nun çalışmaları ile gerçek zamanlı görüntüleme özelliği kazandırılmış ve konfokal mikroskop endüstrinin vazgeçilmez temel optik ölçme cihazı haline gelmiştir. Bu çalışma kapsamında mikro ayna dizinli (DMD™) optik anahtarların yardımı ile yeni bir tip konfokal mikroskop geliştirilmiştir. Geliştirilen bu yeni ölçme sisteminde mikro ayna dizini ölçülecek yüzey üzerine 1-1 görüntülenmiş ve bu sayede yüzlerce noktanın aynı anda video frekansında ölçülmesi gerçekleştirilmiştir. 3D yüzeyin elde edilmesi çeşitli yüksekliklerde elde edilen 2D bilgilerinin üst üste getirilmesi ile oluşturulmuştur. Bu çalışma sırasında mikroskobun optik tasarımı ve elde edilen optik sistemin geliştirilme aşamaları bütün detayları ile verilmiş, geliştirilen deneysel düzenek detayları ile tartışılmıştır. Ölçümler sırasında 50 defa büyütmeli ve 0.95 NA’ya sahip mikroskop objektifi ile yapılan ölçümlerde yatay çözünürlük değeri 1.5 µm olarak bulunmuştur. Sonuçların bu kadar iyi olmasında kullanılan mikro ayna dizinli elemanın önemli bir rolü olmuştur. Geliştirilen sistemin ölçme kapasitesi farklı ölçme standartları kullanılarak örneklendirilmiştir. Anahtar Kelimeler: DMD, optik ölçümler, konfokal mikroskop.In this paper a new method for non-contact scanning of engineering surfaces will be presented. Similar to the classical confocal microscope principal but without using real physical pinholes a new method that uses Digital Micromirror Device (DMDTM) as virtual illumination pinhole and selective CCD camera as virtual detection is developed. With this study, this new, flexible and highly accurate a micromir-ror-based system will be introduced. The concept concerning system layout and system performance together with the measurement results will be presented.Confocal microscopy was first described by M. Minsky in 1957 and in last couple decades it becomes one of the most powerful tool for 3D characterization of complex engineering surfaces. In reflection mode confocal microscopy applications a point illumination source is imaged onto object by using a microscope objective (first focus point). This focusing point on object results with maximum intensity on a detector by passing through the detector pinhole (second focus point) where the lights from defocused neighborhoods object regions are strongly suppressed by the pinhole. In other words, the detector signal that is determined by the pinhole size is reduced strongly by defocusing the specimen. This characteristic of confocal system gives us a chance to make optical sectioning with high vertical resolution discrimination by suppressing the scattered light from defocused object position. It is also well known that confocal microscopy gives some improvements in the sense of lateral resolution compared to the classical microscopy. (DMDTM) technology was developed by Texas Instruments. The DMD that used in the setup consists of 600x800 programmable micromirrors. Each of these mirrors has 16 m x 16 m square size with a 1m gap between them and each mirror tilt 10 around the diagonal axis with help of underlying memory cel. DMD as a member of MEMS device can also be used as a light switch. By combining the DMD with a suitable light source and optics, the DMD reflects the incoming beam either into or out of the microscope objective pupil by using a simple beam steering technique. By combining the light switch advantages of DMD unit with pulse width modulation application it is also possible to create gray scale operation, which can be used to obtain uniform illumination on CCD. By controlling the DMD pixels as an optical light switch any size and any shape pinholes, which are imaged through the optical system onto object where they are reflected and later imaged again onto CCD camera chip, can be created. On the CCD camera reflected intensities from the object are measured by the CCD pixels that are related with DMD's "on" pixels. The measured intensities reach its maximum when the object is confocally in focus with the DMD and the CCD. Intensity data are measured and stored while the object is moving through the focal plane of the optical system. Finally maximum's of the obtained intensity curves, which are also known as depth response curves, link to the corresponding motor position and the 3D profile of the specimen can be reconstructed. The advantages of the DMD based optical scanner can be listed as follows; conventional scanning devices such as Nipkow disk or tilting mirrors that introduce vibration and mechanical noises to system are eliminated, important flexibilities are introduced by DMD application, critical parameters such as pinhole size and pinhole shape can easily be changed, local illumination, which supplies uniform illumination on detector, can be introduced. The main challenges are differences between the images produced by the real illumination pinhole and the DMD, respectively, is the contrast ratio. The ground level intensity of the DMD image is higher because of stray light from the mirror edges and the protective glass layer. At the same time, the maximum intensity is lower because of transmission loss through the glass and reflection loss of the mirror elements. However, although the contrast ratio is worse with a DMD, the depth response curves taken with a regular pinhole and with a DMD show perfect comparability. This new microscope offers unique flexibility for pinhole size and shape that existing system can not do. It is also showed that the measurement results of the developed system are comparable with the stylus instruments and DMD based optical systems are an alternative to tactile techniques. Keywords: DMD, optical measurement, confocal microscopy
Modeling and rule based control of hybrid electric vehicles
Get PDFHibrid elektrikli araçlar, atmosferi kirletmeyen taşıtların geliştirilmesinde ara çözüm olarak karşımıza çıkmaktadır. Global ısınmaya neden olduğu ve insan sağlığına zarar veren kirletici gazlar açığa çıkartmaları nedeniyle içten yanmalı motorlar ile çalışan yol taşıtlarında emisyonlara sıkı sınırlamalar getirilmekte, yenilenebilir ve temiz enerji üzerine yapılan çalışmalar giderek yoğunlaşmaktadır. Yakıt hücresi ve hidrojen enerjisi ile çalışan araç teknolojilerinde, hidrojen yakıtının doğada saf halde elde edilememesi ve bu nedenle hidrojen elde ediniminde fosil yakıtlar ile çalışan santrallerin kullanılması, daha az ya da hiç karbon içermeyen yakıtların yol taşıtlarında kullanılmasında engel teşkil etmektedir. Bataryaların fosil yakıtlara göre enerji kapasitelerinin ve sağladıkları menzil miktarının çok düşük olması nedeniyle, hibrid elektrikli araçlarda, içten yanmalı motorların düşük verim ile çalıştığı bölgelerde bataryalar yardımcı güç kaynağı olarak kullanılmakta, dolayısı ile araç seyahati süresince içten yanmalı motorların ortalama verimleri daha yüksek tutularak yakıt tasarrufu sağlanmaktadır. Hibrid elektrikli araçlar üzerine yapılan çalışmalar, sıfır emisyonlu araç teknolojilerinin alt yapısını da güçlendirmektedir. Hibrid elektrikli araçlarda ana problem, bir araya getirilen bileşenler arasındaki güç dağılımının, araç seyahati esnasında gerçek zamanlı olarak hesaplanabilmesi problemidir. Ticari hibrid elektrikli araçlarda, kural tabanlı kontrol yöntemleri ve mekanizmaları kullanılmaktadır. Hibrid elektrikli araçlarda bu kısıtlamaların giderilebilmesi için, gerçek zamanlı kullanılabilecek optimizasyon yöntemleri üzerinde çalışmalar yoğunlaşmıştır. Anahtar Kelimeler: Hibrid elektrikli araçlar, modellenmesi, kural tabanlı kontrol.The increase in temperature of atmosphere is mostly attributed to human activity due to the combustion products of excessively used fossil fuels.These products create greenhouse effect whereby the planet's surface temperature increases. Use of renewable and clean energy sources is the best solution to reduce increase rate of warming, to mitigate the results of climate change and not to go beyond the irreversible point for the sustainability of life on the planet. The second major source of green house gases comes after electricity generation is transportation sector due to increasing traveling demand as well as its fastest growing rate. There are stringent emission limits stipulated by governors. The proposed emission limits for near future can no longer be satisfied by Internal Combustion Engines (ICE) despite the good advancements in engine technologies. There are numerous studies to adapt clean energy sources on road vehicles. Hydrogen and pure electric energy is seen as an excellent solution for zero emission vehicles. But there are some obstacles for both power sources. The use of hydrogen as common fuel in internal combustion is seen to be unfeasible in immediate future, due to storage, production and availability problems. Hydrogen is not an energy source but it is an energy carrier. Besides this its well-to-wheel efficiency is low with respect to fossil fuels. As to batteries, their poor energy density and long charging time hampers the use of batteries as main power source in on road vehicles. The best solution is to use less or carbon intensive fuels or increasing average efficiency of ICE by using secondary power source in the vehicle. Hybrid vehicles which combine at least two power sources are temporary solution on the way of zero emission vehicles. Hybridization provides means of fuel consumption and emission reduction. Using secondary power source allows down-sizing the engine. Smaller engines operate more efficiently than bigger ones since internal combustion engines are designed to operate efficiently at high loads. Recuperation of the thrown energy and engine stop option are another advantages of hybrid vehicles in fuel economy. Power distribution strategy between energy sources and wheels is of great importance to exploit hybrid vehicles features and this may give satisfactory results even in the situations where engine down-sizing and idle stop cannot be implemented. Power management is a complicated global optimum problem since it involves too many objectives such as fuel consumption and emission reductions as well as drive-ability and acceleration performance of hybrid vehicle. Dynamic Programming (DP) technique generally is used to solve global optimum problems with non-linear constraints. Due to the computational burden and uncertainty in driver's power demand, dynamic programming technique cannot be handled real-time with available computation technologies. Optimum power split strategy is determined offline for a given drive cycle and control rules are extracted at the end of DP solution.There are alternative techniques developed that give sub-optimal solutions approaching global optimum results and can be implemented real-time. These methods are based on finding optimum power split ratio in a time interval by applying predictive control or finding instantaneous optimum power split by using equivalent fuel consumption methods. The vehicle speed profile in shorter time intervals is estimated and DP solution is computed for optimum power split in model predictive control methods. Equivalent fuel quantity of battery energy is converted by using mean efficiencies for a defined cycle and then best power split ratio is chosen. Modeling and rule based control methodology of a converted vehicle is explained in this study. The Ford Transit light commercial vehicle is converted to a hybrid electric vehicle. Since it has front and rear wheel drive versions are available in the market, mounting an electric motor to rear axle of front wheel drive version resulted in a parallel hybrid electric vehicle. The construction of longitudinal hybrid electric vehicle models is given. The use of these models to develop rule based control and simulation results are given. Keywords: Hybrid electric vehicles, rule based control
Hopf bifurcations in a power System and damping oscillations
Get PDFBu çalışmada, Senkronaltı Rezonans (SSR) oluşan bir elektrik güç sistemindeki Hopf çatallanmaları incelenmekte ve kararsız burulma salınımlarının sönümlendirilmesi için tasarlanan bir kontrolör sunulmaktadır. SSR araştırmaları için geliştirilen IEEE İkinci Gösterge Modelinin birinci sistemi kullanılmıştır. Senkron makinenin amortisör sargıları doğrusal olmayan modele dahil edilmiştir. Seri kompanzasyon kapasitörü tesis edilmiş olan enerji iletim hatlarına bağlı senkron makineler, potansiyel olarak senkronaltı elektrik modunun, türbin-generatör şaft sisteminin burulma salınım modları ile etkileşimine maruz kalabilirler. Modellenen elektrik güç sisteminde meydana gelen Hopf çatallanmalarının hangi tip olduğu, birinci Lyapunov katsayılarının analitik olarak hesaplanması ile belirlenmiştir. Sabit ikaz uygulanan modelde kritik-altı Hopf çatallanması meydana gelmektedir. Diğer yandan, Otomatik Gerilim Düzenleyicisinin (AVR) eklenmesi ile modelde kritik-üstü Hopf çatallanması oluşmaktadır. Ayrıca, SSR sonucu ortaya çıkan kararsız burulma salınımlarının sönümlendirilmesi için, zaman gecikmeli geri besleme kontrol teorisine dayanan bir kontrolör tasarlanmıştır. Kontrol girdisi olarak sadece senkron makine rotorunun açısal hızını kullanan kontrolörün zaman gecikme ve kazanç parametreleri için uygun değerler, sistemin dinamik cevabını değerlendiren bir performans endeksi hesaplanarak belirlenmiştir. Tasarlanan kontrolörün etkili sonuçlar verdiği benzetimler yardımı ile gösterilmiştir. Kontrolör etkinliği değerlendirilirken, AVR ve kontrolör çıkış sınırlayıcıları da modele dahil edilmiş ve seri kapasitör kompanzasyonunun pratik işletme değerleri için kontrolörün etkili olduğu görülmüştür. Anahtar Kelimeler: Senkronaltı Rezonans, hopf çatallanması, lyapunov katsayıları, zaman gecikmeli geri besleme kontrolü.Series capacitor compensation of AC transmission lines as a means of increasing load carrying capacity and enhancing transient stability has a widespread use in power systems, particularly in the North America. On the other hand, potential danger of interaction between torsional oscillation modes of the turbine generator shaft system and the subsynchronous electrical mode may arise in electric power systems consisting of turbine-generators con-nected to transmission lines with series compensation capacitors. This phenomenon is called Subsynchronous Resonance (SSR). Unless adequate measures are implemented, unstable torsional mode oscillations due to SSR can lead to catastrophic turbine-generator shaft failures, as occured at Mohave power plant in 1970 and 1971. Since then, considerable effort to the analysis of SSR phenomenon has been devoted by researchers and industry professionals. In this study, Hopf bifurcations in a power system susceptible to SSR is investigted and a novel controller based on the delayed feedback control theory to stabilize unstable torsional oscillations caused by SSR is presented. Bifurcation theory is employed for the analysis of torsional oscillations in a power system which consists of a synchronous generator connected to an infinite busbar through two parallel transmission lines one of which is equipped with a series compensation capacitor. The first system of the IEEE Second Benchmark Model for Subsynchro-nous Resonance studies has been used. Damper windings of the synchronous generator are included in the nonlinear model. The state equations representing the dynamics of the electrical system, mechanical system and the excitation system are obtained separately and then combined into one set of ordinary differential equations. Occurrence of Hopf bifurcations in the model at certain values of the series compensation factor has been verified by tracing the eigenvalues of the Jacobian matrix evaluated at equilibrium. Loss of stability occurs in the first and second torsional oscillation modes through Hopf bifurcation due to SSR. Instead of using the Floquet multipliers method, the first Lyapunov coefficient has been computed analytically to determine the type of Hopf bifurcations (supercritical or subcritical), thereby stability condition of the limit cycles emanating from the Hopf bifurcation points. It is found that subcritical Hopf bifurcation occurs in the model without an Automatic Voltage Regulator (AVR). On the other hand, in the model with AVR, supercritical Hopf bifurcation occurs. Time domain simulations in MATLAB-Simulink are presented to demonstrate the validity of analytic findings.The proposed controller is based on the delayed feedback control theory. The Time Delay Auto-Synchronization (TDAS) controller requires the measurement of the synchronous generator rotor angular speed as the only input. The difference between the value of the controller input signal in -time unit in the past and its current value is multiplied by a gain to obtain an output signal which is combined into the AVR as the stabilizing signal.The effective performance of the controller in providing sufficient damping for the unstable torsional oscillations depends on the correct setting of time delay and gain parameters of the controller. For this purpose, an optimization performance index (OPI), which evaluates damping performance of the controller in time-domain dynamic responses of the model, has been defined.Time-domain simulations in MATLAB-Simulink were carried out to evaluate the effectiveness of the TDAS controller in providing additional damping for the unstable torsional oscillations at various series compensation levels, provided that the time delay and gain parameters are correctly set. Performance of the TDAS controller has been investigated in the presence of AVR limiters in order to obtain a realistic assessment. The TDAS controller output limiter is also included so that the impact on the AVR's voltage regulating performance remains limited. Time domain simulations are presented to demonstrate the effectiveness of the proposed controller even in the presence of the limiters within the practical operating ranges of series capacitor compensation. Keywords: Subsynchronous Resonance, hopf bifurcation, lyapunov coefficients, delayed feedback control
Evaluating state of health of Li-ion polymer batteries
Get PDFGünümüzde birçok enerji depolama çözümünde, yüksek enerji ve güç yoğunluklarına sahip olmaları nedeni ile Li-iyon polimer tip hücreler tercih edilmektedir. Li-iyon polimer hücrelerde, elektrotlar arasında bulunan seperatör malzeme elektriksel olarak yalıtkan fakat iyonik olarak iletken bir malzemedir. Bu malzemenin yapısı, hücrenin aşırı zorlanma durumlarında özelliğini kaybetmekte ve hücreyi arızalı konuma düşürerek güvenlik problemleri meydana getirmektedir. Hücrelerde geri döndürülemez değişiklilerin meydana geldiği bölgelerden biri elektrot ile seperatör arası katı elektrolit geçişlerinin yaşandığı bölgedir. Bu çalışmada, elektrokimyasal empedans spektroskopi yöntemi ile li-iyon polimer pillerin hücre kinetik parametreleri elde edilmiştir ve hücrelerin zorlanmış dolma ve boşalma durumlarında bu parametrelerin değişimi kuramsal olarak incelenmiştir. Li-iyon polimer pillerde oluşabilecek yanlış doldurma ve boşaltma işlemleri sebebi ile meydana gelen geri döndürülemez etkilerin klasik hücre modelleri tarafından tam olarak yansıtılamadığı görülmüştür. Bu nedenle çalışmada hücre eşdeğer devre modeli arıza durumularına göre geliştirilmiş ve sınıflandırılmış, yeni geliştirilmiş hücre eşdeğer devresi modeli ile pil sağlamlık durumunun daha iyi yansıtılacağı önerilmiştir. Yapılan deneysel çalışma ile, normal dolma ve boşalma durumlarında klasik pil modelinin, sağlamlık durumunun değerlendirmesi için yeterli olduğu görülmüştür. Aşırı dolma ve boşalma durumlarının ve etkilerinin incelendiği deneysel çalışmalar neticesinde klasik modelin durum değerlendirme için yetersiz kaldığı ispat edilmiş ve bu çalışmada önerilen modelin arıza durumlarını daha gerçekçi biçimde yansıttığı görülmüştür. Anahtar Kelimeler: Li-iyon polimer hücre modeli, aşırı şarj, aşırı deşarj, sağlamlık durumu.As much as the batteries involve to our lives in any technologic area as energy storage devices -in our case Li batteries - gain is much importance. Battery state definition is even more important with the complex energy storage solutions. In most cases having a Battery Management System (BMS) integrated with cells is necessary, because of specific applications. One of the main tasks in Battery Management is the determining the battery state by means of charge and health. The battery manufacturers or suppliers have high concern to have a proper battery for the specific application. Charging and discharging of batteries are critical since it is an external intervention to the cell, exciting cell chemistry. When they are not controlled properly there is high risk for battery state of health and the application. The literature reports various different approaches to estimating state of heath (primarily capacity fade). These include the discharge test, which completely discharge a fully cell in order to determine its total capacity; chemistry dependent methods, such as measuring the electrolyte density; ohmic tests such as resistance, conductance or impedance tests perhaps combined with fuzzy logic algorithms. The impedance techniques have been widely used in the last two decades for investigating the kinetic of primary or secondary cells and determining their state of charge or state of health. Electrochemical impedance spectroscopy method is a time consuming but a well proven technique for impedance measurement. In order to have an idea or make a decision on a "Battery State", state of charge and state of health parameters should be obtained. State of function could easily be evaluated after these determinations. However, state of function may differ according to the operating conditions and it is "user defined". Having the accurate value of state of charge and state of health for detecting failure is very important. Changes in state of charge can be defined as reversible changes in a battery. After proper usage and charging of a battery, effective capacity, internal resistance, open circuit voltage and gas production of the battery yield positive trend comparing the initial values. If this parametric changes act as irreversible changes, battery state of health is affected negatively, comparing to the initial state of the battery. Measuring only the cell terminal voltage and esti-mating the cell status is commonly used technique in most applications, bringing us possible faults while easy measurement technique. On contrary to the fact that, it is possible to detect internal short circuit and cell open circuit while it is not possible to detect irreversible changes on self discharge and internal resistance increase or active power loss by only voltage measurement. Therefore generally a small excitation current signal is applied to cell terminals in order to involve impedance to the measurement parameters. This study aims to identify the measurable parametric changes between cell terminals occur during overcharge and overdischarge process of Li-ion polymer batteries. These parametric chances will give the opportunity to detect and evaluate the failure of the battery. In this study, Li-ion polymer cell kinetic parameters were obtained by electrochemical impedance spectroscopy method and changes in these parameters were analyzed theoretically in cases of forced charging and discharging. It was seen that, classical cell models were not sufficient enough to mirror the irreversible effects on Li-ion polymer cells caused by improper charging and discharging procedures. Therefore cell equivalent circuit was improved and classified according to the failure states and it is suggested that the improved model is better reflecting the cell state of health. Experimental studies denote that classical cell model is sufficient and classical method is proper for state of health determination under normal charging and discharging cases. It was proved by experiments concentrated on overcharge and overdischarge characteristics that classical cell model is not sufficient and suggested new model is more realistic for state of health determination. Keywords: Li-ion polymer battery model, over-charge, overdischarge, state of health
Fault morphology and paleoseismology of the İzmit-Sapanca Lake segment on North Anatolian Fault
Get PDFThe North Anatolian Fault (NAF) is one of the most destructive fault zones of the world and it lies throughout the northern Turkey with 1500 km length nearly in east-west trending arc shape. It is almost totally broken with large earthquakes during 20th century except two main seismic gaps: Yedisu seismic gap in the east and Marmara seismic gap in the west. The last destructive earthquakes occurred in the eastern Marmara region in 17 August and 12 November 1999 and 150 km and 50 km sections of the NAF were ruptured between Yalova and Düzce respectively. North Anatolian Fault has a relatively narrow deformation zone between Erzincan and Bolu, but it bifurcates to the west of Bolu and separates different main tectonic and morphological units from each other in the eastern Marmara Region. These units are; İstanbul-Zonguldak Zone (or Kocaeli peneplain in morphotectonic manner), Armutlu-Almacık Zone (Armutlu-Almacık High or Samanlı Mountains in morphotectonic manner) and Sakarya Continent (or Bursa-Bilecik relief in morphotectonic manner). Between the Gulf of İzmit and the Sapanca Lake the NAF follows an elongated depression and constitutes the boundary between Kocaeli peneplain and the Samanlı Mountains. The 17 August 1999 earthquake ruptured five segments on NAF between Yalova and Gölyaka (Düzce). These segments are named as Yalova, Karamürsel-Gölcük, İzmit-Sapanca Lake, Sapanca-Akyazı and Karadere from west to east. The surface rupture of 1999 İzmit earthquake between the Gulf of İzmit and the Sapanca Lake, the İzmit-Sapanca Lake segment, has mainly followed this elongated depressional morphology. The morphologic features, observed along the surface rupture, indicate that the surface rupture of 1999 İzmit earthquake was also followed by past earthquakes. These features are elongated ridges, offset streams and hills, sag ponds and depressional areas. In the eastern part of the Gulf of İzmit, in the southwestern part of Kullar village, Yaylacık Hill is offset as 420 m by the fault. The measured offset of the river next to the Yaylacık Hill is 380 m in minimum and 450 m in maximum. To the east, Sarımeşe Hill, on the south of Sarımeşe village, is mapped as an elongated ridge. The right step-overs on the west and east of Tepetarla village are represented by depressional swampy areas. To the eastwards, around Acısu village, the deflected streams and the sag ponds are the results of long-term activity of the NAF in the region. The comparison of the measured offset along the segment and the slip rates derived from recent GPS measurements reveals that the NAF has been active along the same traces at least since 20.000 years on İzmit-Sapanca Lake segment. In order to determine the past earthquakes that ruptured the segment, a trench is excavated on the eastern part of the İzmit-Sapanca Lake segment, east side of Acısu village, where the surface rupture follows the northern slope of an east-west trending ridge. On the trench site, 1999 İzmit earthquake surface rupture trends N85ºE direction as two branches and limits a depressed area which is located on the easternmost part of the site. The trench, with a length of 21 m and a maximum depth of 2,5 m, is excavated perpendicular to these two branches of the surface rupture. The stratigraphy of the trench is dominated by clay layers which have different physical properties. According to the stratigraphical and structural relationships three past event horizons are mapped in the trench. The event horizons are dated with radiocarbon dating (C14) of two charcoal samples. The youngest event horizon (ACSP-1) is before A.D.1300 and should represent an earthquake which happened around A.D.1000’s. Merging the results of previous paleoseismic investigations on the segment and correlation with historical records, 26 October 989 earthquake is a good candidate for this event horizon. The older event (ACSP-2) is before A.D.1300 and after A.D.79-140 dates. According to the calculated sedimantation velocity for the trench site with only these two dates, this event horizon may reveal the 15 August 554 historical earthquake. The oldest event horizon (ACSP-3) observed in the trench is before A.D.79-140 according to radiocarbon dating. The A.D.120 historical earthquake, which caused a considerable damage on the region is a possible earthquake for this event horizon. Keywords: North Anatolian Fault, 1999 İzmit earthquake, paleoseismology, fault morphology, İzmit-Sapanca Lake segment.Doğu Marmara Bölgesi’nde Kuzey Anadolu Fayı (KAF), Bolu’dan batıya doğru çatallanarak kollara ayrılır ve farklı ana morfotektonik üniteleri sınırlar. Bu üniteler; Kocaeli penepleni, Çamdağ-Akçakoca yükselimi, Adapazarı-Karasu koridoru, Armutlu yarımadasında yer alan Samanlı Dağları ve doğusundaki Almacık dağından oluşan Armutlu-Almacık yükselimi ile KAF zonudur. İzmit-Sapanca Gölü arasında KAF bir oluk morfolojisini takip eder ve kuzeyde ve güneyde iki farklı özellikte morfolojik alanı birbirinden ayırır. Kocaeli penepleni olarak anılan kuzey kesim oldukça yumuşak bir topografya sunar ve ortalama yüksekliği 250-300 m civarındadır. Güney kesimde ise, Samanlı Dağları, kuzeye göre oldukça yüksek bir topografya izlenir ve bu kesimdeki en yüksek nokta olan Kel Tepe 1602 m yüksekliğindedir. İzmit Körfezi ile Sapanca Gölü arasında kalan bölgede, 1999 İzmit depremi yüzey kırığı yaklaşık doğu batı yönde izlenen bu oluk morfolojisini takip etmiştir. Yüzey kırığı boyunca izlenen uzamış sırt, ötelenmiş dere ve tepeler, fay gölcükleri ve çöküntü alanları faylanmanın bir süredir bu güzergâhı takip ettiğini göstermektedir. Güncel GPS gözlemlerinden elde edilen kayma hızı değerlerine göre bu yapılar, İzmit-Sapanca Gölü segmenti üzerinde en az 20.000 yıldır KAF tarafından takip edilmiş olmalıdır. Segmentin doğu kesiminde eski deprem belirleme amacıyla açılan hendekte izlenen stratigrafik ve yapısal ilişkilerin değerlendirilmesi sonucunda 1999 İzmit depremi öncesi üç eski deprem seviyesi gözlenmiştir. Gözlenen eski deprem seviyeleri, tarihsel depremlerden M.S.120, 15 Ağustos 554 ve 26 Ekim 989 depremleri ile deneştirilmiştir. Anahtar Kelimeler: Kuzey Anadolu Fayı, 1999 İzmit depremi, paleosismoloji, fay morfolojisi, İzmit-Sapanca Gölü segmenti
Economic and technical evaluation of the desulphurization processes at power stations using lignite
Get PDFBu çalışmada, kömür kullanılan termik santrallerde oluşan baca gazı içerisindeki kükürt dioksit (SO2) yayınımının en aza indirilerek SO2’nin çevre ve insan sağlığına olumsuz etkilerini ortadan kaldıracak/azaltacak belli başlı baca gazı desülfürizasyon yöntemlerinin ekonomik ve teknik açıdan değerlendirilmesi amaçlanmıştır. Bu şekilde Türkiye’nin yerli kaynağı olan linyit, elektrik üretiminde daha etkin değerlendirilmiş olacaktır. Bu amaca yönelik olarak Türkiye’de mevcut linyit rezervlerinin durumu ve ortalama fiziksel ve kimyasal özellikleri verilerek Türkiye’de ve dünyada kullanılan yanma sonrası baca gazı arıtma prosesleri incelenmiş, bunlar arasından en yaygın kullanılan ıslak yöntem, yaygınlaşmakta olan püskürtmeli kurutma ve gelişmekte olan kuru enjeksiyon yöntemleri seçilerek irdelenmiştir. Yöntemlerde kullanılacak sorbent olarak kireçtaşı, kireç ve trona seçilmiştir. Proseslerin ekonomikliğini etkileyen en önemli parametrelerden olan sorbent maliyetini düşürmek ve SO2 tutma verimini arttırmak amacıyla Beypazarı trona yataklarının değerlendirilmesi konusunda araştırma yapılmıştır. Desülfürizasyon yöntemleri arasında ekonomik mukayese yapmak amacıyla yatırım maliyetlerinin hesaplanmasında Gutrie yöntemi kullanılmıştır. Termik santral kapasitesi, kullanılacak kömürün ısıl değeri ve toplam kükürt yüzdesi değişkenlerine bağlı olarak baca gazı arıtma tesislerinin seçilecek yöntem ve sorbente göre yatırım ve işletme maliyetini hesaplayabilen Turbo Pascal programlama dilinde bilgisayar programı yazılmıştır. Programda ıslak yöntem için iki ( kireçtaşı ve trona), püskürtmeli kurutma yöntemi için iki (kireç ve trona) ve kuru enjeksiyon için üç (kireçtaşı, kireç ve trona) farklı sorbent için yatırım ve işletme maliyeti hesaplanabilmektedir. Proseslerin yatırım maliyetlerinin, kapasite ve kullanılan kömürün kükürt yüzdesine bağlı olarak üç boyutlu grafikle gösterimi yapılmış ve bu değişkenlerin bir fonksiyonu olarak maliyet modeli geliştirilmiştir. Anahtar Kelimeler: Desülfürizasyon, termik santraller, kükürt dioksit, absorbsiyon, trona.Due to industrial development and population growth Turkiye’s energy demand is increasing every year. Although renewable energy sources are becoming widespread these sources are not sufficient enough to meet all of the energy demand of Turkey in the near future. Therefore fossil fuels are going to be used for a long time for domestic heating and electricity production. The disadvantage of using fossil fuels is sulfur dioxide (SO2) emissions during the combustion according to the sulfur content of the fuel. Turkey’s energy consumption depends heavily on fossil fuels. Therefore SO2 emission level is going to be higher than the legal limits according to Industrial Based air Pollution Control Regulation (22 JULY 2006) since our lignite has a low calorific heating valve and high sulfur content which are 1807 kcal/kg and 1.85 % respectively. Although there are disadvantages of using lignite for electricity production it’s our native energy source and by applying appropriate desulphurization methods it is possible to reduce emission of SO2 to lower levels. Removal of SO2 is not only legal obligation but also an act for protection of the public health and environment. Because an important effect of SO2 is it’s contribution to acid rain. Acid aerosols cause chlorosis, the loss of chlorophyll and plasmolysis, tissue collapse of leaf cells in plants. And cause bronchoconstriction, above 1 ppm in air and throat; eye and nose irritation above 10 ppm concentration, on human beings.In this study, most prevalent way to prevent SO2 emission, desulphurization flue gas after combustion of fossil fuel especially lignite, is elaborated. In pre-combustion processes coal is crushed, grinded in coarse particles and treated with water by flotation in lavers. But this physical treatment decrease the piritic sulfur in coal and can not remove the organic bonded sulfur. Overall decrease in sulfur content is 10-40% in this operation. In desulfurization during combustion dry sorbent is added to the combustion chamber or sorbent is pressed with the fine coal powder during briquetting operation. The disadvantage of this process is sintering of sorbent material such as limestone, lime or soda at higher temperatures up to 800-1000 ºC. Technical and economical evaluation of desulphurization methods is given. Conventional wet scrubbing, spray dry and dry sorbent injection methods are investigated. Types of sorbents used in desulphurization processes such as magnesium, calcium, sodium, potassium based and ammonia sorbents are illustrated and reactions of them with SO2 is given. In order to determine the most economical method capital investment of three different desulphurization processes (wet, spray dry and dry injection) is calculated by using Gutrie’s “equipment module cost technique”. In calculation of capital investment of those three major desulphurization methods these steps are followed; preparation of detailed process sheet, material balances, list of equipment and list of utility consumption. This technique depends on multiplying the bare module cost of equipment at base conditions by the factors relating to pressure, material and equipment type. Base case in this study is carbon steel material and operations near ambient pressure. By using the base case, that is 100 MW thermal power station using heating value of 2000 kcal/kg, 2% sulfur content coal and using 40% excess air for dry injection method and 210 MW for wet method, computer programme is produced for calculating the total capital investment and total annual cost. An algorithm for computer program is prepared to calculate the capital investment and total annual cost for desulphurization methods which are investigated. Finally a computer program is written to determine the lowest capital investment among those three methods of desulphurization is found as dry sorbent injection. The disadvantage of this method is the limitation of SO2 removal. Maximum SO2 removal efficiency is 75% for limestone and 85% when lime is used. In order to overcome this problem using more active sorbent, evaluation of Beypazarı trona is investigated(90 % desulfurization rate for dry injection). Although it is more active than calcium based sorbents, it is much more expensive in the market. But if obtained by solution mining from Beypazarı it is going to be cheaper than both lime-stone and lime. Capital investment cost model for certain methods are developed as a function of plant capacity and sulfur content for certainsorbents.As an example for dry sorbent injection method in the case of trona, as a sorbent, capital cost model is as follows; TCI= 230 600*(MW)0.61.(S%)0.3 ($). Keywords: Desulphurization, power stations, sulfur dioxide, sorbent, absorption, trona
State feedback control problem for a class of linear neutral systems
Get PDFBu çalışmada durumunun gecikmesi zaman değişkenli, durumunun zamana göre birinci türevinin gecikmesi sabit olan lineer neutral bir sistemin asimptotik kararlılığı için yeterli koşullar Lyapunov-Krasovskii yaklaşımı ile sistemin durumundaki gecikmeye bağımlı, durumunun zamana göre birinci türevindeki gecikmeden bağımsız olarak Lineer Matris Eşitsizliği (LME) cinsinden elde edilmiştir. Daha sonra sistemi asimptotik kararlı hale getirmek için, durum geri besleme kontrol kuralı bir kontrol girdisi vasıtası ile sisteme uygulanarak, kapalı çevrim sistemi elde edilmiştir. Elde edilen sistemin asimptotik kararlılığı için yeterli koşullar yine Lyapunov-Krasovskii yaklaşımı ile sistemin durumundaki gecikmeye bağımlı, durumunun zamana göre birinci türevindeki gecikmeden bağımsız olarak LME cinsinden elde edilmiştir. Elde edilen LME, Matlab LMI Toolbox paket programı ile çözülmüştür. Bu çalışmada, literatürdeki benzer çalışmalarda bulunan durum gecikmesinin zamana göre birinci türevinin birden küçük bir sayıya eşit olma şartı ortadan kaldırılmıştır. Burada yeterli koşullar simetrik bir LME’nin negatif belirli bir matris olması ile elde edilmiştir. Elde edilen LME’nin negatif belirli olması için köşegenindeki tüm elemanlarının negatif olmaları gerekmektedir. Durum gecikmesinin zamana göre birinci türevi birden büyük bir sayı olduğunda LME’nin köşegenine negatif olmayan bir terim gelmektedir. Burada bu sorunu ortadan kaldırmak için LME’yi elde etme aşamasında elde edilen eşitsizliğe sıfıra eşit olan bir terim eklenerek LME’nin sorun çıkaran köşegen elemanına serbest olarak seçilebilen bir terimin eklenmesi sağlanmıştır. Son olarak elde edilen sonuçlar örnekler üzerinde uygulanıp elde edilen sayısal değerler diğer çalışmalarla karşılaştırılmıştır. Anahtar Kelimeler: Durum gecikmesi, Asimptotik kararlılık, lineer matris eşitsizliği.The mathematical system representations of some physical and biologic control problems depend also on the states of the systems in the past. Systems of this type are called as time delay systems. The delay may also be on the first time derivative of the states of the systems. These types of systems constitute the general form of the time delay systems and are named as neutral systems. The delay, depending on the system considered can be constant or time varying, and the time delay systems are investigated as a separate class of dynamical systems. The existence of the time delay in any system, can cause to instability and bad performance. This is the reason why the stability and the performance analyses of this type of systems became important both in the theoretical and the practical means. The time delay systems are separated to two classes as, systems that can be represented with, a system of first order ODE?s and the system of first order PDE?s. In this article the time delay systems belonging to the first class are investigated.. In the years 1990?s, the time delay systems are classified as independent of the delay and as depended to the delay. In the case of independent of the delay, the system is stable for all positive values of the delay but for dependent to delay systems, the system is stable for only some positive values of the delay and unstable for the other values. In this article, at first, the model representation of a linear time delay system is introduced, in which the state has a time varying delay and the first time derivative of the state has a constant delay. The sufficient conditions for the asymptotic stability of the system is obtained as linear matrix inequality by the Lyapunov-Krosovskii approach as dependent to the delay of the state of the systems but independent of the delay in the first time derivative of the state. According to the Lyapunov-Krasovskii approach, the system is stable if the first time derivative of the Lyapunov-Krasovskii functional which is constructed for the system is less than zero. In this work, by writing the first time derivative of the functional in terms of a vector and a matrix, it is shown that it is less than zero by obtaining the matrix as a negative defnite matrix. Aiming to stabilize the time delay systems, state feedback control problems are investigated in the literature. The state feedback control problem is to investigate the closed loop system which can be obtained by appyling a control input to the system. In state feedback control problems the control input is constructed with the state of the system and a regulating matrix. In this article, it is also constructed a state feedback control problem for the system given in the first section. The sufficient conditions for the asymptotic stability of the closed loop system is abtained in terms of linear matrix inequality again by the Lyapunov Krasovskii approach as dependent to the delay of the state of the system but independent of the delay in the first time derivative of the state. In the literature,in most of the articles, there is a restriction on the first time derivative of the delays of time delay systems as it has to be less than one. In this article, this restriction is removed by adding a term which is equal to zero to the first time derivative of the Lyapunov-Krasovskii functional. Here the sufficient conditions are obtained with the matrices which are negative definite symetric matrices. For these types of matrices it is necesarry that their elements on the diagonal are all negative. Here, when the first time derivative of the delay is greater than one, nonnegative terms appear on the diagonal of the matrices. This problem is solved by adding a zero term on the first time derivative of the Lyapunov-Krasovskii functional. This provides to define a free parameter on the diagonals in order to make them negative in spite of a first time derivative of the delay function that is greater one. At last, the theoretical results obtained are applied to examples and the values obtained for the upper limit of the time delay are given in tables. Keywords: State Delay, asymptotic stability, linear matrix inequality
Improvement of structural dynamic finite elements responses by using super elements and structuring
Get PDFBu çalışmada yapısal dinamik problemlerin analizlerinde sonlu elemanlar yöntemi ile elde edilen cevaplarının süper elemanlar ile iyileştirilmesi incelenmiştir. Geliştirilen yeni model derecesi düşürme (MDD) yaklaşımları ile olumlu sonuçlar elde edilmiştir. Bu yeni yaklaşımlar sistem zaman cevaplarının eşitliğini sağlayacak serbestlik derecelerinin aktif serbestlik dereceleri olarak MDD uygulanmış sistemin içine taşınması temeline dayanmaktadır. Hazırlanan Matlab kodları ile geliştirilen model derecesi düşürme yöntemi örnek yapılara uygulanmış ve alınan zaman cevabı sonuçları, orijinal modelin sonuçları ile karşılaştırılmıştır. Tüm bu karşılaştırmalarda Rayleigh sönüm modeline uygun farklı katılık orantılı sönüm matrisi durumları dikkate alınmış ve farklı model dereceleri için hesaplama zamanları açısından sonuçlar değerlendirilmiştir. Ayrıca farklı MDD teknikleri ile elde edilen sistem toplam enerji miktarı orijinal modelin toplam enerjisi ile karşılaştırılmıştır. Çalışmada alt yapılara bölme (AYB)-“Substructuring” yöntemi de incelenmiştir. Geliştirilen Matlab kodu ile plak sistemleri üzerinde AYB uygulamları yapılmış, sonuçlar orijinal model cevabı ile karşılaştırılmıştır. Oluşturulan süper elemanların kullanılması ile de hesaplama zamanları önemli ölçüde düşürülmüştür. Ancak süper eleman oluşturmaya harcanan zamanın yüksek olduğu ve AYB yönteminin geliştirilen MDD yönteminden daha kötü performans gösterdiği görülmüştür. Yapılan tüm karşılaştırmalar sonucunda çalışmada incelenen yöntemlerin çok düşük olan sönüm durumları dışında, orijinal model ile uyumlu zaman ve frekans cevapları verdiği, MDD uygulanmış sistemin orijinal model ile aynı enerji seviyelerinde bulunduğu ve karşılaştırılan diğer MDD yöntemlerinden çok daha az hesaplama zamanına ihtiyaç duyulduğu görülmüştür. Anahtar Kelimeler: Sonlu elemanlar yöntemi, model derecesi düşürme, alt yapılara bölme, süper eleman.In this study, the responses obtained by the Finite Element Analyses of structural dynamic problems are studied. With the developed model order reduction approach, some improvements have been gained. The developed model order reduction method is essentially based on the equality of the total energies of both original and reduced systems and therefore it is named as “Equality of the total energies”. In the new approach, respecting the degrees of freedoms (DOF)s that give responses conforming with original system is assumed as the main criteria for selection of active DOFs. In this study, the main significant step is the selection of the active DOFs according to their influence to the system time response. The groups of active are application points of the external loadings and the DOFs having high stress or deflection values maximum because they are very important to reveal the right system response. For better accuracy, DOFs close to loading application points are also transferred into reduced system. Heuristic method had been also used for the selection of the active DOFs by some trials and errors to get better consistency between the original system response and reduced system response. Developed model order reduction method was applied to a sample 2D truss system and cantilever plate by some Matlab codes, and the results of the reduction analyses are compared with the original system responses in response to various loadings, eg. İmpulse, step and sinusoidal inputs. In the same Matlab codes, time responses of some other model order reduction methods –Forward differences, Newmark integration and impulse response invariant (IRI)- are also implemented to the same original model. Various Rayleigh damping models for the sample system are taken into account in all these comparisons and the results of analyses for different model orders are evaluated in terms of calculation time and accuracy. Frequency domain responses of the original and the reduced systems by different approaches are also compared with each other based on Bode diagrams by considering the stiffness proportional damping. In parallel, the total energy levels of the reduced systems are also compared with the original system energy level. While auditing of the system responses and Bode diagrams, it is noted that the compatibility of both the original and the reduced systems increases in parallel with the stiffness proportional damping value. In evaluation of the results, it could be expressed that the change in stiffness proportional damping value does not affect the calculation time. While comparing the total energies of original and reduced systems, it is observed that their consistency is good enough to state that both systems have the same system characteristic. Bode diagrams which reflect frequency response of a system, are assumed to be the main criteria to evaluate the performance of the reduced system for both high and low frequencies. It is concluded in general that when the number of an element type used in the analyses decreases, the amount of the DOFs which could be omitted from the original system increases and also the order of the reduced system decreases by keeping the same expected accuracy. As a result of observation, the limit of the model order reduction depends on the selected elemen type. Another conclusion is that general behavior of the damped or undamped systems do not affect the selected element numbers for the reduced system. In the study, substructing method is also taken into considerations. By using Matlab codes, substructuring is implemented into a plate system and the results are compared with the original system. It is observed that the calculation time is extremely reduced by using super elements Nevertheless, since the time for calculation of super elements is long, it is seen that substructuring exhibits worse performance than developed model order reduction method. After all comparisons, it is noted that the developed method gives compatible time and frequency responses with the original model except too low stiffness proportional dampings. It is also observed that the energy level of the reduced system obtained by this new model order reduction method is almost the same with the energy level of the original model. Finally, the most advantageous feature of equality of the total energies method was determined on the calculation time and it needs less calculation time than the other compared model order reduction methods during all examples carried out in the study. Keywords: Finite element method, model order reduction, substructuring, super element
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