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Showing posts with label Electrical Seminar Topics. Show all posts
Showing posts with label Electrical Seminar Topics. Show all posts

Wednesday, July 6, 2011

Adaptive Cruise Control

The concept of assisting driver in the task of longitudinal vehicle control is known as cruise control. Starting from the cruise control devices of the seventies and eighties, now the technology has reached cooperative adaptive cruise control. This paper will address the basic concept of adaptive cruise control and the requirement to realize its improved versions including stop and go adaptive cruise control and cooperative adaptive cruise control. The conventional cruise control was capable only to maintain a set speed by accelerating or decelerating the vehicle. Adaptive cruise control devices are capable of assisting the driver to keep a safe distance from the preceding vehicle by controlling the engine throttle and brake according to the sensor data about the vehicle. Most of the systems use RADAR as the sensor .a few use LIDAR also. Controller includes the digital signal processing modules and microcontroller chips specially designed for actuating throttle and brake. The stop and go cruise control is for the slow and congested traffic of the cities where the traffic may be frequently stopped. Cooperative controllers are not yet released but postulations are already there. This paper includes a brief theory of pulse Doppler radar and FM-CW LIDAR used as sensors and the basic concept of the controller.

Wednesday, January 12, 2011

Computer Clothing:Digital clothes that able to perform some of the PC functions

There is a major movement going on in the electronics and computer industries to develop wearable devices for what’s being called Post-PC era. We are now at the dawn of that era and some of these devices are already making their way to the consumer market .Computerized clothes will be the next step in making computers and devices portable without having to strap electronics into our body. These digital clothes will able to perform some of the PC functions. These devices are small in size and portable. This apparel can be used to read our heart rate and breathing. The LED monitors could even be integrated into this apparel to display text and images.

microprocessor based auto synchronization

The manual method of synchronization demands a skilled operator and the method is suitable for no load operation or normal frequency condition. under emergency condition such as lowering of frequency or synchronizing of large machines a very fast action is needed, which may not be possible for a human operator. Thus there is a need of autosynchroniser in a power station or in an industrial establishment where generator are employed. This paper describes a microprocessor based set up for synchronizing a three phase alternator to a busbar. Also existing methods of synchronization are mentioned.

Wednesday, November 10, 2010

Integrated Gate Commutated Thyristor (IGCT)

The Integrated Gate Commutated Thyristor (IGCT) combines the advantages of the hard driven GTO thyristor, including its dramatically improved turn- off performance, with technological breakthroughs at the device, gate-drive and application levels. Homogenous switching area of the IGCT up to the dynamic avalanche limits. Snubber circuits are no longer needed. Improved loss characteristics allow high frequency applications extending into the kHz range. A new IGCT device family with integrated high- power diodes has been developed for applications in the 0.5-6 MVA range, extending to several 100 MVA with series and parallel connections. A first 100 MVA inverter based on the IGCT has been in commercial operation and confirms the very high level of reliability of this new technology. Other new application using the IGCT platform includes ABB’s new ACS1000 drive for medium voltage applications.

BiCMOS silicon technology:Electronics Seminar

The need for high-performance, low-power, and low-cost systems for network transport and wireless communications is driving silicon technology toward higher speed, higher integration, and more functionality. Further more, this integration of RF and analog mixed-signal circuits into high-performance digital signal-processing (DSP) systems must be done with minimum cost overhead to be commercially viable. While some analog and RF designs have been attempted in mainstream digital-only complimentary metal-oxide semiconductor (CMOS) technologies, almost all designs that require stringent RF performance use bipolar or semiconductor technology. Silicon integrated circuit (IC) products that, at present, require modern bipolar or BiCMOS silicon technology in wired application space include the essential optical network (SONET) and synchronous digital hierarchy (SDH) operating at 10 Gb/s and higher.

The viability of a mixed digital/analog. RF chip depends on the cost of making the silicon with the required elements; in practice, it must approximate the cost of the CMOS wafer, Cycle times for processing the wafer should not significantly exceed cycle times for a digital CMOS wafer. Yields of the SOC chip must be similar to those of a multi-chip implementation. Much of this article will examine process techniques that achieve the objectives of low cost, rapid cycle time, and solid yield.

Adaptive Piezoelectric energy harvesting circuit

This paper describes an approach to harvesting electrical energy from a mechanically excited piezoelectric element. A vibrating piezoelectric device differs from a typical electrical power source in that it has a capacitive rather than inductive source impedance, and may be driven by mechanical vibrations of varying amplitude. An analytical expression for the optimal power flow from a rectified piezoelectric device is derived, and an “energy harvesting “ circuit is proposed which can achieve this optimal power flow. The harvesting circuit consists of an ac-dc rectifier with an output capacitor, an electrochemical battery, and a switch-mode dc-dc converter that controls the energy flow into the battery. An adaptive control technique for the dc-dc converter is used to continuously implement the optimal power transfer theory and maximize the power stored by the battery. Experimental result reveal that the use of the adaptive dc-dc converter increases power transfer by over 400% as compared to when the dc-dc converter is not used.

Coordinated secondary voltage control to eliminate voltage violation in power system contingencies

In order to achieve more efficient voltage regulation in a power system, coordinated secondary voltage control has been proposed, bringing in the extra benefit of enhancement of power system voltage stability margin. The study is presented by the e.g. with two SVCs and two STATCOMs in order to eliminate voltage violation in systems contingencies. In the paper, it is proposed that the secondary voltage control is implemented by a learning fuzzy logic controller. A key parameter of the controller is trained by P-type learning algorithm via offline simulation with the assistance of injection of artificial loads in controller’s adjacent locations. A multiagent collaboration protocol, which is graphically represented as a finite state machine, is proposed in the paper for the coordination among multiple SVCs and STATCOMs. As an agent, each SVC or STATCOM can provide multilocation coverage to eliminate voltage violation at its adjacent nodes in the power system. Agents can provide collaborative support to each other which is coordinated according to the proposed collaboration protocol.

Molecular Electronics:A new technology competitive to semiconductor technology

Semiconductor integration beyond Ultra Large Scale Integration (ULSI), through conventional electronic technology facing some problems with fundamental physical limitations. Beyond ULSI, a new technology may become competitive to semiconductor technology. This new technology is known is as Molecular Electronics.

Molecular based electronics can overcome the fundamental physical and economic issues limiting Si technology. Here, molecules will be used in place of semiconductor, creating electronic circuit small that their size will be measured in atoms. By using molecular scale technology, we can realize molecular AND gates, OR gates, XOR gates etc.

The dramatic reduction in size, and the sheer enormity of numbers in manufacture, are the principle benefits promised by the field of molecular electronics

Tele-Immersion (TI) :Free full Engineering seminar reort

It is 2010 and you have a very important meeting with your business associates in Chennai. However you have visitors from Japan coming for a mega business deal the same day. Is there any technology by which you can deal with both of them? The answer is yes and the name of that technology is Tele-Immersion. Tele-Immersion is a technology by which you’ll interact instantly with your friend on the other side of the globe through a simulated holographic environment. This technology, which will come along with Internet2, will change the way we work, study and get medical help. It will change the way we live. Tele-Immersion (TI) is defined as the integration of audio and video conferencing, via image-based modeling, with collaborative virtual reality (CVR) in the context of data-mining & significant computation. The 3D effect behind the tele-immersion makes it feel like the real thing. The ultimate goal of TI is not merely to reproduce a real face-to-face meeting in every detail, but to provide the “next generation” interface for collaborators, world-wide, to work together in a virtual environment that is seamlessly enhanced by computation and large databases. When participants are tele-immersed, they are able to see and interact with each other and objects in a shared virtual environment.

Tele-immersion can be of immense use in medical industry and it also finds its application in the field of education

Friday, October 22, 2010

Magnetic resonance imaging (MRI):most modern scanning techniques

Magnetic resonance imaging (MRI) is one of the most modern techniques which uses the principle of magnetic resonance to create the images of body parts for diagnostic purposes. When the resonating magnetic object is a an automatic nucleus, it is called nuclear magnetic resonance (NMR) the use of NMR to produce images of the body is called magnetic resonance imaging (MRI) Magnetic nuclei in the human body act like tiny bar magnets with north and south poles. When the body is placed in a large magnetic field, these bar magnet 1ine with the external magnetic field. Then by passing a radio frequency pulse through the body some of these little magnets absorb energy and change direction. When the radio waves are turned of, the body’s nuclei return to the original orientation releasing the absorbed energy and this is processed by a computer in to image.

Maglev: A combination of super conducting magnets and linear motor technology

Ever since the discovery of the wheel, man has been in constant pursuit to achieve better and faster means of transportation. Maglev means magnetic levitation. It is the system which magnetically levitates the vehicle. These ultra high speed trains are acting as an indispossible resource to make the world smaller.

Maglev is a generic term for a family of technologies in which a vehicle is suspended, Guided and propelled by magnetic forces. the basic idea of a maglev is to levitate it with magnetic fields. So there is no physical contacts between the train and rails. Recent developments in cryogenics, superconductivity, power electronics, aerodynamics and vehicle dynamics has led to a renewed. Maglev can move people and goods with much mobility and speed, using much less energy at lower cost and with greatly reduced pollution compared to the existing modes of transport.

Fault localization on ungrounded and high resistance grounded low voltage systems

One of the most common and difficult problems to solve in industrial power systems is the location and elimination of ground fault. Ground faults that occur in ungrounded and high resistance grounded systems do not draw enough current to trigger circuit breaker or fuse operation, making them difficult to localize. Techniques currently used to track down faults are time consuming and cumbersome. A new approach developed for ground fault localization on ungrounded and high resistance grounded low voltage systems is described. The system consists of a novel ground fault relay that operates in conjunction with low cost indicators permanently mounted in the circuit. The remote fault relay employs digital signal processing to detect the fault, identify the faulted phase and measure the electrical distance of the fault from the substation. The remote fault indicators are used to visually indicate where the fault is located. The resulting system provides a fast, easy, economical and safe detection system for ground fault localization.

FACTS :A concept introduced by Electric Power Research Institute (EPRI)

FACTS is a concept introduced by Electric Power Research Institute (EPRI), USA.It is actually a group of advanced transmission technologies that rely on high speed, solid-state electronics, rather than electromechanical devices. By this concept, the apparent impedance of a transmission line is controlled according to certain algorithm. Thus the power system operation is made more reliable, controllable and efficient.

FACT system is a promising method, which can be implemented into the system for enhancing system stability by damping out system oscillations. At the heart of FACT are thyristors, which permit control and switching of megawatt levels of power within milliseconds.

Electronic fuel injection system

In the electronic fuel injection system we use different sensor unit to assess accurate data from various engine parts and which is applied to Engine Control Unit (ECU), such as air manifold pressure, engine speed, crank shaft angle. ECU uses the data to calculate the required amount of fuel in the particular engine condition. This seminar deals with the basic principle of Electronic Fuel Injection (EFI).

Electric tractions:A pollutions free and energy efficient mode of transportations

Continuous development in semiconductor technology for the last three decades or more have led to the availability of a host of high power semiconductor devices and fast versatile VLSI (very large scale integration ) chips enabling proper control of such power devices. These developments have enabled a phenomenal growth of power electronics which basically deals with processing of electric power to make it suitably for various applications. A major application of power electronics in this period has been in the field of railways tractions all over the world. This had led to benefits like smoother drives for passenger comfort, energy conservation, higher operational speeds, cost effective maintenance besides helping the growth of electronics industry in general. Indian railways are helping the growth of electronics industry in general. Indian railways are one of the largest railways systems in the world and offer a big scope for applications of power electronics. From the late 60s few efforts have been made to introduce such systems with mixed results. Greater challenge lies before the Indian industry to make use of this particular application area for its growth.
Electric tractions is a pollutions free and energy efficient mode of transportations, it offers excellent alternative source of energy other than fossil fuels. Indian railways decided to go in for 25kv ac systems and selected main line heavy density routes.

Monday, September 20, 2010

Electronic nose(E-noses) A System that detect and identify odours and vapours

The harnessing of electronics to measure odour is greatly to be desired. Human panels backed up by gas chromatography and mass spectrometry are helpful in quantifying smells, but they time are consuming, expensive and seldom performed in real time in the field. So it is important that these traditional methods give way to a speedier procedure using and electronic nose composed of gas sensors. Electronic nose are E-noses are the systems that detect and identify odours and vapours, typically linking chemical sensing devices with signal processing, pattern recognition and artificial intelligence techniques which enable uses to readily extract relevant and reliable information.

CTs and PTs

With the increasing demand for electric power, the economics of power transmission requires the use of high transmission line voltages. This leads to escalation of cost for conventional CTs and PTs.

This paper provides an economical alternative, for the use of CTs and PTs for the measurement of current and voltage. The method is an optical method using lasers. The method employs two types of devices; free path and enclosed path devices. The basic principle of the optical method is based upon magneto-optic effect, electro optic effect and the electro gyration effect.

This paper concludes with the suggestion for future development. Instead of using free path, the enclosed path method is suggested.d88eafd484ee4ecf974e07836d1f6d30

Contactless Energy Transfer System (CETS)

Most mains operated equipment in use today is connected to the supply via plugs and sockets. These are generally acceptable in benign environments but can be unsafe or have limited life in the presence of moisture. In explosive atmospheres and in undersea applications special connectors must be used. This paper describes a technique, the Contactless Energy Transfer System (CETS), by which electrical energy maybe transmitted, without electrical connections or physical contact, through non-magnetic media of low conductivity. CETS, which has been used to transfer upto 5KWs across a 10mm gap, employs high frequency magnetic coupling and enables plug in power connections to be made in wet or hazardous environmental conditions without the risk of electric shock, short-circuiting or sparking. Energy may be transmitted without the necessity for accurately manufactured “plug and socket” mechanisms and may be transmitted from source to load even when there is a relative motion. Load source voltage matching may be made inherent to the system.

Condition monitoring of transformer: Electrical Seminar Topic

Transformers are a large part of the component structure of the electricity system. Knowing the condition is essential to meeting the goals of maximizing return on investment and lowering total cost associated with transformer operation.

In order to reconcile both decreasing maintenance spending and reliable service, condition based maintenance (CBM) is often proposed. The successful application of CBM lies in obtaining information transformers, so that, on the one hand, a critical condition will be noted early enough to take measures and on the other hand, so that only minimal maintenance is being applied to transformers still in good condition.

The paper covers the following areas.
• General aspects of aging in transformers.
• An overview of condition monitoring methodology with partial discharge patterns in focus.
• Partial discharge measurement and diagnostics on power transformer using a multi channel digital PD detector.

Brush-less servomotor

A brush-less servomotor has been developed by using interdisciplinary mechatronics engineering. A mechanical switching device (commutator) is replaced by electronic circuits and controllers resulting in maintenance free and high performance servo drive.
The brush-less servomotor is an ac motor, in all respects and is in fact called the ac servomotor. Combined with a dedicated control device, the performance of the brush-less servomotor is found to be equal to the performance of the high performance dc servo motor.
The rotational speed of dc servomotor is generally varied by changing the voltage applied to the armature. As the armature voltage is nearly proportional to the rotational speed, the speed can be slowed down as much as is required by lowering the applied voltage. On the other hand the rotational speed of the ac motor is generally varied by changing the frequency. However the frequency has its limits of variation. A wide range of speed variation, which is a feature of servomotors, cannot be obtained by using only a simple inverter.
In dc motor when the current flows in the electrical conductor, after passing through the brushes and the commutator in the magnetic field generated by permanent magnets N and S, torque is generated. For getting a stable torque proportional to current, the line of magnetic force should intersect the c of current at right angles in a dc motor. This is enabled by the use of rectifiers (a commutator and brushes).
In ac motors slip ring is used instead of a commutator and a power source of alternating current makes the rotor rotate continuously at the rotational speed corresponding to the applied frequency. But the brushes of the ac motors can be eliminated by changing the revolving armature structure in to revolving field type.