This document discusses electric propulsion technologies for rockets. It describes three main types of electric propulsion: electrothermal, electrostatic, and electromagnetic. Electrothermal propulsion heats propellant electrically, including resistojets which heat propellant on a solid surface and arcjets which use an electric arc. Ion engines and Hall thrusters are examples of electrostatic propulsion which accelerate ions with electric and magnetic fields. Electric propulsion provides much higher specific impulse than chemical rockets, allowing for higher exhaust velocities and lower fuel usage. While slower, electric propulsion can reduce launch costs for missions where time is not critical.
Fuses are short pieces of metal that melt and break the electric circuit when excessive current flows. They provide overcurrent protection in a cheap, automatic, and maintenance-free way. There are two main types: low voltage semi-enclosed fuses that can be rewired after blowing, and high rupturing capacity cartridge fuses that must be replaced after operation. High voltage fuses come in cartridge, liquid, and metal clad types to interrupt higher fault currents. Compared to circuit breakers, fuses have smaller breaking capacity, faster operation time but require replacement after each operation.
This document discusses methods for obtaining peak power from photovoltaic (PV) systems, including manual tracking and maximum power point tracking (MPPT) algorithms. It describes how PV cells work to convert sunlight into electricity. MPPT algorithms like perturb and observe (P&O) and incremental conductance (INC) are used to automatically track the peak power point by matching the impedance of the solar module to the load. These algorithms help ensure PV systems operate efficiently without needing manual adjustment.
A basic presentation on Solar Cell, principle of Solar Cell, Types of Solar Cell and the advantage & disadvantage of solar cell with its application. The presentation is fully explained using diagram.
Solar sails use radiation pressure from the sun for propulsion and have minimal moving parts. They produce very small thrusts but can be used repeatedly over long periods. A seminar discussed the physical principles behind solar radiation pressure and how it produces small forces on sails. Attitude control is needed to maintain the craft's orientation against various forces. Testing is challenging on Earth but applications could include satellites for trajectory corrections and missions close to the sun. Various sail configurations and materials have been proposed but deployment challenges have limited real-world testing until Japan's 2010 IKAROS mission, the first to use a solar sail as a primary propulsion system.
An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower, thus benefiting from more mechanical and aerodynamic options.
The Ion-propulsion engine or Ion thruster system’s efficient use of fuel and electrical power enables modern spacecraft to travel farther, faster, and cheaper than any other propulsion technology. Chemical rockets have a fuel efficiency up to 35%, but ion thruster have demonstrated fuel efficiencies over 90%. An ion thruster ionizes a neutral gas by extracting some electrons out of atoms, creating a cloud of positive ions. These thrusters rely mainly on electrostatics as ions are accelerated by the Coulomb force along an electric field. Temporarily stored electrons are finally reinjected by a neutralizer in the cloud of ions after it has passed through the electrostatic grid, so the gas becomes neutral again and can freely disperse in space without any further electrical interaction with the thruster.
PV cells convert sunlight directly into electricity without moving parts. PV systems can be installed on rooftops and other structures. The sun is a nuclear fusion reactor that provides radiation energy, with only a small proportion reaching Earth's surface. Traditional energy sources like gas, oil and coal are finite, while sunlight reaching Earth could meet energy needs with only 0.01% utilization. PV cell performance is affected by factors like temperature, shading, and irradiance level, with output decreasing at higher temperatures. Different cell types have varying efficiencies depending on material used.
This document discusses electric propulsion technologies for rockets. It describes three main types of electric propulsion: electrothermal, electrostatic, and electromagnetic. Electrothermal propulsion heats propellant electrically, including resistojets which heat propellant on a solid surface and arcjets which use an electric arc. Ion engines and Hall thrusters are examples of electrostatic propulsion which accelerate ions with electric and magnetic fields. Electric propulsion provides much higher specific impulse than chemical rockets, allowing for higher exhaust velocities and lower fuel usage. While slower, electric propulsion can reduce launch costs for missions where time is not critical.
Fuses are short pieces of metal that melt and break the electric circuit when excessive current flows. They provide overcurrent protection in a cheap, automatic, and maintenance-free way. There are two main types: low voltage semi-enclosed fuses that can be rewired after blowing, and high rupturing capacity cartridge fuses that must be replaced after operation. High voltage fuses come in cartridge, liquid, and metal clad types to interrupt higher fault currents. Compared to circuit breakers, fuses have smaller breaking capacity, faster operation time but require replacement after each operation.
This document discusses methods for obtaining peak power from photovoltaic (PV) systems, including manual tracking and maximum power point tracking (MPPT) algorithms. It describes how PV cells work to convert sunlight into electricity. MPPT algorithms like perturb and observe (P&O) and incremental conductance (INC) are used to automatically track the peak power point by matching the impedance of the solar module to the load. These algorithms help ensure PV systems operate efficiently without needing manual adjustment.
A basic presentation on Solar Cell, principle of Solar Cell, Types of Solar Cell and the advantage & disadvantage of solar cell with its application. The presentation is fully explained using diagram.
Solar sails use radiation pressure from the sun for propulsion and have minimal moving parts. They produce very small thrusts but can be used repeatedly over long periods. A seminar discussed the physical principles behind solar radiation pressure and how it produces small forces on sails. Attitude control is needed to maintain the craft's orientation against various forces. Testing is challenging on Earth but applications could include satellites for trajectory corrections and missions close to the sun. Various sail configurations and materials have been proposed but deployment challenges have limited real-world testing until Japan's 2010 IKAROS mission, the first to use a solar sail as a primary propulsion system.
An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower, thus benefiting from more mechanical and aerodynamic options.
The Ion-propulsion engine or Ion thruster system’s efficient use of fuel and electrical power enables modern spacecraft to travel farther, faster, and cheaper than any other propulsion technology. Chemical rockets have a fuel efficiency up to 35%, but ion thruster have demonstrated fuel efficiencies over 90%. An ion thruster ionizes a neutral gas by extracting some electrons out of atoms, creating a cloud of positive ions. These thrusters rely mainly on electrostatics as ions are accelerated by the Coulomb force along an electric field. Temporarily stored electrons are finally reinjected by a neutralizer in the cloud of ions after it has passed through the electrostatic grid, so the gas becomes neutral again and can freely disperse in space without any further electrical interaction with the thruster.
PV cells convert sunlight directly into electricity without moving parts. PV systems can be installed on rooftops and other structures. The sun is a nuclear fusion reactor that provides radiation energy, with only a small proportion reaching Earth's surface. Traditional energy sources like gas, oil and coal are finite, while sunlight reaching Earth could meet energy needs with only 0.01% utilization. PV cell performance is affected by factors like temperature, shading, and irradiance level, with output decreasing at higher temperatures. Different cell types have varying efficiencies depending on material used.
This document provides an overview of how alternators work in vehicle charging systems. It discusses the major components of the charging system including the battery, alternator and regulator. It then describes the internal components and functioning of the alternator, including the rotor assembly, stator windings, rectifier bridge and regulator. Diagrams are included to illustrate the charging circuit, alternator component identification and the magnetic and electrical processes within the alternator that produce direct current output.
This document discusses different methods of grounding electrical systems, including solid grounding, resistance grounding, reactance grounding, and resonant groundings using a Peterson coil. Solid grounding directly connects the neutral point to earth, holding it at earth potential but allowing high fault currents. Resistance grounding limits fault current by connecting through a resistor. Reactance grounding uses an inductor instead of resistor. Resonant grounding with a Peterson coil adjusts the inductance to balance capacitive currents and prevent arcing faults.
The document discusses reliability criteria for bulk power supply systems. It defines key terms like reliability, security, adequacy, and discusses how reliability criteria are used in system planning and operation. Specifically, it establishes the most economic operating conditions under normal conditions and ensures the system can withstand disturbances without violating criteria. The document uses examples of system operating limits and disturbance-performance tables to illustrate how limits are determined and assessed using reliability criteria.
The functions of an excitation system are
to provide direct current to the synchronous generator field winding, and
to perform control and protective functions essential to the satisfactory operation of the power system
The performance requirements of the excitation system are determined by
Generator considerations:
supply and adjust field current as the generator output varies within its continuous capability
respond to transient disturbances with field forcing consistent with the generator short term capabilities:
rotor insulation failure due to high field voltage
rotor heating due to high field current
stator heating due to high VAR loading
heating due to excess flux (volts/Hz)
Power system considerations:
contribute to effective control of system voltage and improvement of system stability
The document discusses eddy current brakes, which use magnetic fields to induce eddy currents in conductors to slow rotation or movement. There are two types - circular brakes use a disc that generates eddy currents when exposed to a magnetic field, while linear brakes induce currents in rails using a magnet held near the rail. Eddy current brakes have advantages like contactless braking and adjustable braking force, but cannot hold stationary loads. They are used in trains and rollercoasters for safety braking at high speeds. Future applications could replace ordinary brakes and control high speed trains entirely with eddy current brakes.
Maglev trains use magnetic levitation to move along guideways at high speeds without friction. They work by using electromagnetic forces for levitation, guidance, and propulsion. Maglev trains can travel at over 300 mph and have advantages like high speed, low noise and friction, and not needing fossil fuels. However, the initial costs are very high. Current projects exist in Germany, Japan, and China. India is reviewing a proposal for a Maglev train system between Pune and Mumbai. Maglev trains represent an environmentally friendly high-speed transportation option.
Electric propulsion is a form of spacecraft propulsion that uses electrical energy to accelerate propellant using electric and/or magnetic fields. There are several types of electric propulsion systems including electrostatic, electromagnetic, and electrothermal. Electric propulsion provides higher fuel efficiency than chemical rockets by expelling propellant at higher velocities, though it produces significantly lower thrust. While not suitable for launching from Earth, electric propulsion is well-suited for missions requiring small thrust over long durations, such as maintaining a spacecraft's orbit or powering interplanetary transfers.
This document provides an overview of flywheel energy storage systems. It discusses how flywheels store kinetic energy by rotating a mass at high speeds, and can act as both a load to charge the flywheel using a motor and a source to discharge energy using a generator. The key components are the flywheel, motor/generator, power electronics, magnetic bearings, and external inductor. Flywheel systems are best for high power applications between 100kW-2MW for durations of 12-60 seconds. The advantages are high power and energy density, long lifetime, and fast recharging, while disadvantages include complex bearings and potential safety issues if the flywheel fails.
The document discusses flywheel energy storage systems (FESS). It first provides an introduction to energy storage and defines FESS. It then reviews literature on FESS technology and applications. The main components of FESS are described as the flywheel rotor, electric machine, power electronics, bearings and housing. Examples of FESS applications discussed include use in the Porsche 911, transportation, railways, and spacecraft. FESS provide advantages like high power capability and long lifespan but also have limitations such as potential energy losses over time.
This document discusses different types of starters for 3-phase induction motors, including their operation and advantages/disadvantages. It describes stator resistance, auto-transformer, star-delta, rotor resistance, and direct online starters. The star-delta starter connects the motor in a star configuration at start to reduce voltage and current by 1/3, then switches to delta for run. The direct online starter connects the motor directly to full voltage, providing maximum torque but also maximum starting current of 6-8 times full load current. Variable frequency drives control motor speed by varying supply frequency and voltage.
This document provides an overview of energy efficient motors. It defines an energy efficient motor as one that uses less power to produce the same output as a standard motor. It notes that energy efficient motors have higher efficiencies of 2-6% compared to standard motors due to features like more copper in the windings and reduced fan losses. The document discusses the need for and advantages of energy efficient motors, including energy and cost savings. It also notes some potential disadvantages like higher initial cost and issues with speed control. Applications mentioned include various industrial uses.
There are two types of traction motors used in CLW locomotives: Co-Co and Bo-Bo. Co-Co motors are used in WAG 9 and WAP7 locomotives and have two pinion sizes (15 or 20 teeth), while Bo-Bo motors in WAP5 locomotives do not use pinions. Co-Co motors are 850kW with speeds up to 2584 RPM while Bo-Bo motors are 1150kW with speeds up to 3174 RPM. Both use labyrinth seals including inner and outer seals in the end frames, rotor, and other parts to reduce leakage of gear case oil. Pinions are fitted to the Co-Co motor shafts using a high pressure machine applying 2000 bars
Inrush current reduction in three phase power transformer by using prefluxing...IAEME Publication
This document discusses reducing inrush current in power transformers. It begins by introducing transformers and explaining that inrush current can be up to 10 times the nominal current and cause issues. One method to reduce inrush current is point-on-wave switching, which controls energization based on residual flux. However, measuring residual flux is difficult. The paper proposes a prefluxing technique which sets the initial flux in the transformer before energization using controlled switching. It models a 300MVA, 11/400kV transformer in MATLAB and compares inrush current reduction using point-on-wave switching and prefluxing. The aim is to minimize the peak inrush current and reach steady state current faster.
A flywheel, in essence is a mechanical battery - simply a mass rotating about an axis.Flywheels store energy mechanically in the form of kinetic energy.They take an electrical input to accelerate the rotor up to speed by using the built-in motor, and return the electrical energy by using this same motor as a generator.Flywheels are one of the most promising technologies for replacing conventional lead acid batteries as energy storage systems.
This document provides an overview of ultracapacitors, also known as supercapacitors or double-layer capacitors. It defines ultracapacitors as energy storage devices that store energy electrostatically without chemical reactions. The document describes the construction of ultracapacitors including porous electrodes, an electrolyte, separator, and current collectors. It also explains the formation of an electric double layer and types of ultracapacitors such as double-layer, pseudocapacitors, and hybrid capacitors. Applications mentioned include electronics, electric vehicles, and backup power systems.
This document discusses flywheel energy storage systems. It describes the main components which include the flywheel, motor/generator, power electronics, magnetic bearings, and external inductor. It explains that the motor charges the flywheel by accelerating it to store kinetic energy, and acts as a generator to return the stored energy as electricity. Applications include electric vehicles, backup power systems, and industrial pulsed power. Advantages are high power/energy density and long lifetime, while disadvantages include potential hazards if the flywheel fails and short discharge times.
This document summarizes a study on laser ignition systems for internal combustion engines. It discusses the limitations of conventional spark plug ignition systems and how laser ignition could address these issues. It describes four main types of laser ignition mechanisms and provides details on experiments conducted using a combustion bomb and engine to test laser ignition of fuels like biogas and gasoline. The document also discusses properties and durability testing of optical windows used for laser ignition systems.
1. Unit commitment involves determining the optimal mix of generators to meet expected demand while satisfying operational constraints like minimum up and down times. It aims to minimize total costs which include start-up costs and variable running costs.
2. The example problem determines the lowest cost combination of 3 generators to produce 550MW of power. Various constraints like minimum generation levels and ramp rates must be considered.
3. Key constraints in unit commitment include minimum and maximum generation limits, minimum up and down times, and ramp rates for changing output. System constraints require matching generation to load while maintaining sufficient operating reserves. Environmental and network limits also factor into the optimization.
This document discusses power quality issues related to wind power integration. It begins with an abstract noting how increasing electricity demand is leading to more renewable energy sources like wind power, but wind integration can negatively impact the grid's power quality. The document then covers international power quality standards, defines power quality, and lists various power quality issues caused by wind power like power imbalances, voltage variations, harmonics, and flickers. Challenges of wind power integration to power system stability are also discussed. Finally, the document presents some mitigation strategies for integrating wind energy conversion systems onto the grid.
This document provides an overview of how alternators work in vehicle charging systems. It discusses the major components of the charging system including the battery, alternator and regulator. It then describes the internal components and functioning of the alternator, including the rotor assembly, stator windings, rectifier bridge and regulator. Diagrams are included to illustrate the charging circuit, alternator component identification and the magnetic and electrical processes within the alternator that produce direct current output.
This document discusses different methods of grounding electrical systems, including solid grounding, resistance grounding, reactance grounding, and resonant groundings using a Peterson coil. Solid grounding directly connects the neutral point to earth, holding it at earth potential but allowing high fault currents. Resistance grounding limits fault current by connecting through a resistor. Reactance grounding uses an inductor instead of resistor. Resonant grounding with a Peterson coil adjusts the inductance to balance capacitive currents and prevent arcing faults.
The document discusses reliability criteria for bulk power supply systems. It defines key terms like reliability, security, adequacy, and discusses how reliability criteria are used in system planning and operation. Specifically, it establishes the most economic operating conditions under normal conditions and ensures the system can withstand disturbances without violating criteria. The document uses examples of system operating limits and disturbance-performance tables to illustrate how limits are determined and assessed using reliability criteria.
The functions of an excitation system are
to provide direct current to the synchronous generator field winding, and
to perform control and protective functions essential to the satisfactory operation of the power system
The performance requirements of the excitation system are determined by
Generator considerations:
supply and adjust field current as the generator output varies within its continuous capability
respond to transient disturbances with field forcing consistent with the generator short term capabilities:
rotor insulation failure due to high field voltage
rotor heating due to high field current
stator heating due to high VAR loading
heating due to excess flux (volts/Hz)
Power system considerations:
contribute to effective control of system voltage and improvement of system stability
The document discusses eddy current brakes, which use magnetic fields to induce eddy currents in conductors to slow rotation or movement. There are two types - circular brakes use a disc that generates eddy currents when exposed to a magnetic field, while linear brakes induce currents in rails using a magnet held near the rail. Eddy current brakes have advantages like contactless braking and adjustable braking force, but cannot hold stationary loads. They are used in trains and rollercoasters for safety braking at high speeds. Future applications could replace ordinary brakes and control high speed trains entirely with eddy current brakes.
Maglev trains use magnetic levitation to move along guideways at high speeds without friction. They work by using electromagnetic forces for levitation, guidance, and propulsion. Maglev trains can travel at over 300 mph and have advantages like high speed, low noise and friction, and not needing fossil fuels. However, the initial costs are very high. Current projects exist in Germany, Japan, and China. India is reviewing a proposal for a Maglev train system between Pune and Mumbai. Maglev trains represent an environmentally friendly high-speed transportation option.
Electric propulsion is a form of spacecraft propulsion that uses electrical energy to accelerate propellant using electric and/or magnetic fields. There are several types of electric propulsion systems including electrostatic, electromagnetic, and electrothermal. Electric propulsion provides higher fuel efficiency than chemical rockets by expelling propellant at higher velocities, though it produces significantly lower thrust. While not suitable for launching from Earth, electric propulsion is well-suited for missions requiring small thrust over long durations, such as maintaining a spacecraft's orbit or powering interplanetary transfers.
This document provides an overview of flywheel energy storage systems. It discusses how flywheels store kinetic energy by rotating a mass at high speeds, and can act as both a load to charge the flywheel using a motor and a source to discharge energy using a generator. The key components are the flywheel, motor/generator, power electronics, magnetic bearings, and external inductor. Flywheel systems are best for high power applications between 100kW-2MW for durations of 12-60 seconds. The advantages are high power and energy density, long lifetime, and fast recharging, while disadvantages include complex bearings and potential safety issues if the flywheel fails.
The document discusses flywheel energy storage systems (FESS). It first provides an introduction to energy storage and defines FESS. It then reviews literature on FESS technology and applications. The main components of FESS are described as the flywheel rotor, electric machine, power electronics, bearings and housing. Examples of FESS applications discussed include use in the Porsche 911, transportation, railways, and spacecraft. FESS provide advantages like high power capability and long lifespan but also have limitations such as potential energy losses over time.
This document discusses different types of starters for 3-phase induction motors, including their operation and advantages/disadvantages. It describes stator resistance, auto-transformer, star-delta, rotor resistance, and direct online starters. The star-delta starter connects the motor in a star configuration at start to reduce voltage and current by 1/3, then switches to delta for run. The direct online starter connects the motor directly to full voltage, providing maximum torque but also maximum starting current of 6-8 times full load current. Variable frequency drives control motor speed by varying supply frequency and voltage.
This document provides an overview of energy efficient motors. It defines an energy efficient motor as one that uses less power to produce the same output as a standard motor. It notes that energy efficient motors have higher efficiencies of 2-6% compared to standard motors due to features like more copper in the windings and reduced fan losses. The document discusses the need for and advantages of energy efficient motors, including energy and cost savings. It also notes some potential disadvantages like higher initial cost and issues with speed control. Applications mentioned include various industrial uses.
There are two types of traction motors used in CLW locomotives: Co-Co and Bo-Bo. Co-Co motors are used in WAG 9 and WAP7 locomotives and have two pinion sizes (15 or 20 teeth), while Bo-Bo motors in WAP5 locomotives do not use pinions. Co-Co motors are 850kW with speeds up to 2584 RPM while Bo-Bo motors are 1150kW with speeds up to 3174 RPM. Both use labyrinth seals including inner and outer seals in the end frames, rotor, and other parts to reduce leakage of gear case oil. Pinions are fitted to the Co-Co motor shafts using a high pressure machine applying 2000 bars
Inrush current reduction in three phase power transformer by using prefluxing...IAEME Publication
This document discusses reducing inrush current in power transformers. It begins by introducing transformers and explaining that inrush current can be up to 10 times the nominal current and cause issues. One method to reduce inrush current is point-on-wave switching, which controls energization based on residual flux. However, measuring residual flux is difficult. The paper proposes a prefluxing technique which sets the initial flux in the transformer before energization using controlled switching. It models a 300MVA, 11/400kV transformer in MATLAB and compares inrush current reduction using point-on-wave switching and prefluxing. The aim is to minimize the peak inrush current and reach steady state current faster.
A flywheel, in essence is a mechanical battery - simply a mass rotating about an axis.Flywheels store energy mechanically in the form of kinetic energy.They take an electrical input to accelerate the rotor up to speed by using the built-in motor, and return the electrical energy by using this same motor as a generator.Flywheels are one of the most promising technologies for replacing conventional lead acid batteries as energy storage systems.
This document provides an overview of ultracapacitors, also known as supercapacitors or double-layer capacitors. It defines ultracapacitors as energy storage devices that store energy electrostatically without chemical reactions. The document describes the construction of ultracapacitors including porous electrodes, an electrolyte, separator, and current collectors. It also explains the formation of an electric double layer and types of ultracapacitors such as double-layer, pseudocapacitors, and hybrid capacitors. Applications mentioned include electronics, electric vehicles, and backup power systems.
This document discusses flywheel energy storage systems. It describes the main components which include the flywheel, motor/generator, power electronics, magnetic bearings, and external inductor. It explains that the motor charges the flywheel by accelerating it to store kinetic energy, and acts as a generator to return the stored energy as electricity. Applications include electric vehicles, backup power systems, and industrial pulsed power. Advantages are high power/energy density and long lifetime, while disadvantages include potential hazards if the flywheel fails and short discharge times.
This document summarizes a study on laser ignition systems for internal combustion engines. It discusses the limitations of conventional spark plug ignition systems and how laser ignition could address these issues. It describes four main types of laser ignition mechanisms and provides details on experiments conducted using a combustion bomb and engine to test laser ignition of fuels like biogas and gasoline. The document also discusses properties and durability testing of optical windows used for laser ignition systems.
1. Unit commitment involves determining the optimal mix of generators to meet expected demand while satisfying operational constraints like minimum up and down times. It aims to minimize total costs which include start-up costs and variable running costs.
2. The example problem determines the lowest cost combination of 3 generators to produce 550MW of power. Various constraints like minimum generation levels and ramp rates must be considered.
3. Key constraints in unit commitment include minimum and maximum generation limits, minimum up and down times, and ramp rates for changing output. System constraints require matching generation to load while maintaining sufficient operating reserves. Environmental and network limits also factor into the optimization.
This document discusses power quality issues related to wind power integration. It begins with an abstract noting how increasing electricity demand is leading to more renewable energy sources like wind power, but wind integration can negatively impact the grid's power quality. The document then covers international power quality standards, defines power quality, and lists various power quality issues caused by wind power like power imbalances, voltage variations, harmonics, and flickers. Challenges of wind power integration to power system stability are also discussed. Finally, the document presents some mitigation strategies for integrating wind energy conversion systems onto the grid.
Betonarme yapilardaki donati korozyonunun kimyasal analiziIlhan Söylemez
Turkey is on one of the most active seismic zones in the world. Due to its location, there are countless earthquakes every year. Life and property losses are alive.It is a well-known fact that buildings are damaged due to the corrosion of reinforced concrete structures due to the earthquake reality.In this study, samples of untreated and samples of corrosion were taken from different points of the structure at Istanbul, Ataşehir, Küçükbakkalköy Mah., Cengiz Topel Cad., No: 25 / 27B, the results of the chemical analysis were determined with a spectrometer, the results were interpreted comparatively and the importance of the corrosion of the reinforcement was emphasized.
İş sağlığı güvenliği mevzuat ve kişisel koruyucu donanımlar .pdfŞahabettin Akca
İş sağlığı kanunu,
Mevzuatlar,
Hıfzısıhha kanunu,
Yönetmelikler,
Anayasal güvenceler,
Kişisel koruyucu donanımlar,
Baş, kulak, göz, ayak, solunum ve genel koruyucular vb genel kkd konuları
Hayatı Ahmet Yesevî, Kazakistan Cumhuriye6nin güneyindeki Çimkend şehri yakınlarında bulunan, eski ismi “Sayram”, bugünkü adı “İsCcâp” olan kasabada doğmuştur. Sayram, BaK Türkistan’ın Çimkend şehrinin doğusunda, Şâhyâr nehrinin kolu olan Kara-su üzerinde bulunan bir kasabadır. Bazı kaynaklarda, özellikle Alî Şîr Nevâî’nin “Nefehâtü’l-Üns” adlı eserinde, onun doğum yeri olarak Yesi gösterilmektedir. “Yesi” adı Sovyet döneminde Türkistan olarak değiş6rilmiş6r. Yine onun hikmetlerinde, adının Ahmet, doğum yerinin ise Yesi olduğu geçmektedir.
Analog Sayısal ve Sayısal Analog Çeviriciler hakkında genel bilgiler, mikro işlemci uygulamaları ile çevirimler ve örnek uygulamalar.
kaynak: 320volt.com
Bor Elementi - Şahabettin Akca
1. Doğada Bulunuşu, Minerallerinin Formülleri ve İsimleri....................................3!
2. Fiziksel ve Kimyasal Özellikleri...................................................................6!
3. KullanımAlanları......................................................................................7!
4. Bileşiklerinin Formülleri ve İsimleri.............................................................11!
5. Kaynaklar..............................................................................................12
Magnetic Levitation (Manyetik Levitasyon) - Elektromekanik sistemleri
1. Tokat Gazi Osman Paşa Üniversitesi
Fen Bilimleri Enstitüsü
Danışman
Prof. Dr. Ahmet FENERCİOĞLU
Hazırlayan
Şahabettin AKCA
Mekatronik (Bilgisayar) Mühendisliği
Magnetik Levitasyon
20 Aralık 2018
1
2. Magnetik Levitasyon
Levitasyon (levitation) Türkçe karşılığı ile yükselinimidir. İnsan yada
hayvan vücudunun veya özgül ağırlık olarak havadan daha ağır nesnelerin
görünür herhangi bir fiziksel etkenin yardımı olmadan havaya kaldırılması,
havada asılı kalmasına verilen addır.
Manyetik levitasyon, bir nesnenin manyetik alanlardan başka bir destek
olmadan askıya alındığı bir yöntemdir. Manyetik kuvvet ise yerçekimi
ivmesinin ve diğer ivmelerin etkilerini ortadan kaldırmak için kullanılır.
2
3. Kullanım Alanları
Magnetik levitasyonun kullanım alanları; Maglev trenler, temassız erime
magnetik rulmanlar ve ürün teşhir amaçlı kullanılır. Örnek olarak NASA gibi
şirketlerde simülasyon test uygulamaları rüzgar tünellerinde, enerji üretiminde
kullanılan rüzgar tribünlerinde verimi maksimize etmek için ve askı sistemleri
tozsuz ve temassız olduğu için üretim aşamasında yarı iletken levhaların
taşınmasında yoğun olarak kullanılmaktadır.
Magnev sistemleri elektromanyetik alanın yapısından dolayı doğrusal
olmayan sistemlerdir. Etkin bir kontrol sistemi geliştirebilmek için bu
sistemlerin bir çalışma noktasından doğrusallaştırılması gerekir. Bu amaca
yönelik en popüler denetleyici türlerinden biri olan PD denetleyicilerin
kullanılması bahsedilen çalışma noktasının daha uygun bir şekilde tayini için
idealdir.
MAGLEV SİSTEMİNİN GENEL YAPISI
Tasarlanan magnev sistemi temel olarak demir çekirdek üzerine sarılmış
bobin ve kontrol devrelerinden oluşur.
3
Manyetik
Levitasyon
Örnek Ürün ve
Materyal
Görünümleri,
Maglev Treni
4. !
Yukardaki şekilde de görüldüğü gibi magnev sisteminin genel tasarımı ve
ana elamanları görülmektedir.
$
Yapılan tasarımda görüldüğü üzere sistem demir çekirdek üzerine sarılmış
bobin ve bobinin monte edileceği boyutları verilmiş olan demir sac levhaların
birleşiminden oluşmuştur. Soğutucular, bobindeki bakır iletkenlerin içerisinden
akım geçmesi nedeniyle demir çekirdekte meydana gelecek olan ısınmayı
mümkün olduğunca azaltmak ve sistemin aşırı ısınma nedeniyle zarar
görmesine önlemek amacıyla konulmuştur.
4
5. Bobinin monte edildiği demir sac levha bobin çevresi boyunca
delinmiştir. Bunun nedeni sistemde kaçak akı olması durumunda delikler
vasıtasıyla oluşturulan hava aralıklarının kaçak manyetik akıya büyük bir direnç
göstermesini sağlayarak akıyı zayıflatmak ve akı yolunun demir gövde
üzerinden tamamlamasını engellemektir.
MAGLEV SİSTEMİNİN TEORİK ALT YAPISI VE
MODELLENMESİ
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Yukardaki şekildede görüldüğü gibi daha basit alt sistemle gösterilmiştir.
Bu sistemler; konum algılama alt sistemi, Manyetik indiksiyon alt
sistemi, Denetleyici alt sistem ve DC yükselteç alt sistemleridir. Bu sistemleri
kısaca açıklayacak olursak;
Konum Algılama Alt Sistemi;
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6. !
Kızıl ötesi ışın yayıcı ve alıcı elemanlar manyetik levitasyon sisteminin
gövdesine sabitlenmiştir. Bu sayede kızıl ötesi işinların dağılımının
değişmemesi sağlanmıştır. Yine Şekilde görüleceği üzere cisim direkt olarak bu
kızıl ötesi yayıcı ve alıcı arasında askıda kalmaktadır. Böylece alıcı tarafından
toplanan kızılötesi sinyalinin yoğunluğundaki değişim sadece askıda kalan
cismin dikey eksendeki konumuna bağlıdır. Sonuç olarak algılayıcının
terminallerinde üretilen gerilimi küresel topun bir fonksiyonu olarak uygun bir
hassasiyetle elde edebiliriz.
Yukarıdaki şekilde görülen denkleme göre çıkış gerilimi cismin
konumunu temsil eden x ile olarak değişmektedir.
Vx=Gs.x
Vx:Sensör Çıkış gerilimi
Gs: Sensör Kazanç
Manyetik indiksiyon alt sistemi;
Fg: yerçekimi kuvveti
Fm: Elektro manyetik kuvvet
Fa: İvme Kuvveti
Fa= Fm-Fg
Fg=Mg
Fa=M*d2x/dt2
Burada M=Küresel topun Kütlesi
X=Küresel Topun Konumu
G=Yerçekimi Sbt
6
7. MAGNETİK LEVİTASYON YÖNTEMİYLE CİSİMLER NASIL
HAVADA KALIR?
Fiziksel olarak süper iletken maddelerin varlığına dayanmaktadır.
Kullandığımız iletken maddeler, büyük veya küçük iç dirence sahiptir. Bu
sebeple bize; enerji ile ısı kaybı olarak geri dönmektedir. Süper iletkenlerde bu
sorun yoktur.
Süper iletken madde : Elektiriksel iletkenlikleri sonsuza yaklaşan
maddelerdir. Elektrik akımı dirençle karşılaşmadan süper iletken maddelerin
üzerinden geçebilmektedir. Süper iletkenlerin başka özelliği ise içindeki
mağnetik akıyı mükemmel bir diyamagnetiklik özelliği göstererek dışarı
itmeleridir. Bu diyamanyetik özelliği, Meissner Etkisi olarak tanımlanır. Ayrıca
süper iletken maddelerden yüksek akımlar geçebilir.
Bu iletkenler soğuk alanlarda -189 ile 267 C derece aralığında üretilir.
İnsan yaşamı için çok düşük değerlerde ve bazı canlı gibi davranan metallerde
soğuk onların ham maddesi olduğu için belli bir sıcaklık değerinden sonra süper
iletken özelliğini kaybediyorlar. Kimyasal yöntemler ile maddeyi soğutma
işlemine tabi tutarsak dirençlerini kaybederler. Süper iletkene özelliği kazanan
metaller bundan sonra akım kaynağına olarak kullanılabilirler. Akım Manyetik
alan yayılımı iç alandan dış alana atar, bu sayede büyük kuvvetlerin doğmasını
sağlar. Sıradan mıknatıslardan 10 kat daha güçlü manyetik alan üretirler.
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Süper iletken maddelerin diyamanyetik özelliği sayesinde cisim
yüzeyinde elektirik akımı oluşturularak neredeyse tüm manyetik alanı
itilebilmektedir. Cismin yüzeyinde oluşan manyetik alan maruz bırakılan
manyetik alanı Meissner Etkisi altına alır fakat çok ince bir tabaka da olsa
kullanılan süper iletken madde manyetik alanın kullanılan cisme geçmesine
7
8. sebebiyet veriri. Kullanılan cisme geçen manyetik alan Voretex denilen tüp
şeklinde biliniyor. Bu tüplerin içinde bulunan süper iletkenlik de yerel olarak
kırılıyor ve cisim mnyetik akımının tüplerin içine hapsedilmesini sağlıyor.
Cisim kendini olduğu yere sabitleyebiliyor. Böylelikle magnetik levitation
gerçekleşmiş oluyor.
Maglev Trenleri
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Maglev olarak da bilinen magnetik levitation trenleri de temel olarak bu
ilkeye bağlı olarak çalışmakta. Magnev trenlerinin altında mıknatısa benzetilen
bir yapı bulunmakta bu yapı ile birlikte tren havada asılı bulunmakta havada
haraket edebilmekte Teknolojininde gelişimi ile birlikte mevcut trenlere
kazandırılan hız sürekli arttırılabilmektedir.
Brookhaven Laboratuvarında James Powell ve Gordon Danby, manyetik
levitasyon trenin ilk patentini 1960’lı yıllarda aldılar. Trenlerin araçlardan daha
iyi bir ulaşım aracı olması gerektiğinden yola çıkarak bulundu. Süper iletken
mıknatıs sayesinde treni havaya kaldırıp sürtünmesiz olarak ilerletebileceğini
düşündü.
Ticari olarak ilk defa süper iletken kullanılan yüksek hızlı Maglev treni
2004 yılında Şangay’da açıldı. Şekil olarak U harfine benzer bir modelde
rayların üstünde havada asılı durur. Aynı kutuplar denk geldiğinde bir birini iter,
bu şekilde trenin hareketi sağlanır.
Rayların üç adet görevi vardır:
1) Treni raylardan 12.7 cm havada tutacak manyetik alan oluşturmak.
2) Yatay açıdan, trenin dengede kalmasını sağlamak, istenen konumdan
uzaklaştığından manyetik alan artırılarak raydan çıkmaması sağlanır.
3) AC akım kullanılarak, manyetik olarak itme ve çekme sistemidir.
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9. Maglev trenleri saatte 600 kilometre hızlara çıkabilmektedir. Rekor
sürekli ilerletilmektedir. Prototip olarak Çinde kullanılan trenler saatte 1000 km/
saat hızlara ulaşmaktadır. Bu hızda Türkiye’nin bir ucundan diğer ucuna
yaklaşık 1.5 - 2 saatte gidilebilecektir.
Maglev trenleri sürücüsüz ve sabit hızda hareket etmektedir. Buda kaza
ve çarpışma riskini minimuma indirmektedir.
Vakumlu yapılacak tren veya benzeri sistemler ile 2900 km/saat hızlara
çıkması planlanmaktadır.
Manyetik levitasyon, gelişmekte olan bir alan ilerleyen günlerde kullanım
yerleri ve kapasitesinin artacağı öngörülmektedir.
9
10. Kaynaklar
1-) WHYTE, Chelsea, “How Maglev Works”, U.S. Department of Energy, Washington June 2015
<https://www.energy.gov/articles/how-maglev-works>, (Erişim Tarihi: 15.12.2018)
(Çeviren: http://fizikakademisi.com/2016/06/29/maglev-treninin-calisma-prensibi/ )
2-) YÜCEL Oğulcan, Manyetik Levitasyon, KTÜ-FBE, Lisans, Trabzon Mayıs 2012
3-) Dr. BİLGİSİ, Zeynep, “Maglev Treninin Hızı Saatte 1000 km’nin Üzerine Çıktı”, Tübitak Bilim Genç
Dergisi, 2016 Kocaeli
4-) "Süperiletkenlik." Vikipedi, Özgür Ansiklopedi. 4 Eyl 2018, 18.51 UTC. 15 Ara 2018, 12.31 <//
tr.wikipedia.org/w/index.php?title=S%C3%BCperiletkenlik&oldid=19973417>.
5-) Wikipedia katılımcıları (2017). Levitasyon. Vikipedi, Özgür Ansiklopedi. Erişim tarihi 12.32, Aralık
11, 2018 url://tr.wikipedia.org/w/index.php?title=Levitasyon&oldid=18706423.
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