Project report writing Plagiarism and academic honesty

1 Introduction A technical report is a formal report designed to convey technical information in a clear and easily accessible format. It is divided into sections which allow different readers to access different levels of information. This guide explains the commonly accepted format for a technical report; explains the purposes of the individual sections; and gives hints on how to go about drafting and refining a report in order to produce an accurate, professional document. 11 Originality and plagiarism Whenever you make use of other people's facts or ideas, you must indicate this in the text with a number which refers to an item in the list of references. Any phrases, sentences or paragraphs which are copied unaltered must be enclosed in quotation marks and referenced by a number. Material which is not reproduced unaltered should not be in quotation marks but must still be referenced. It is not sufficient to list the sources of information at the end of the report; you must indicate the sources of information individually within the report using the reference numbering system. Information that is not referenced is assumed to be either common knowledge or your own work or ideas; if it is not, then it is assumed to be plagiarised i.e. you have knowingly copied someone else's words, facts or ideas without reference, passing them off as your own. This is a serious offence. If the person copied from is a fellow student, then this offence is known as collusion and is equally serious. Examination boards can, and do, impose penalties for these offences ranging from loss of marks to disqualification from the award of a degree This warning applies equally to information obtained from the Internet. It is very easy for markers to identify words and images that have been copied directly from web sites. If you do this without acknowledging the source of your information and putting the words in quotation marks then your report will be sent to the Investigating Officer and you may be called before a disciplinary panel. • Plagiarism refers to the unacknowledged borrowing of others’ writing. When you use others’ exact words without citing their work, you are guilty of plagiarizing, whether you “borrow” an entire report or a single sentence. In academic contexts, plagiarism is a form of academic dishonesty. In university classrooms, the teacher usually assumes that the work you turn in is your own original work. If you turn in work that is not your own or that was co-created with others, you are obliged to make that clear to your instructor. When you borrow language from other sources, you are expected to use quotation marks and provide a full bibliographical reference. Whenever you borrow graphics or quote passages, you are legally and ethically obliged to acknowledge that use, following appropriate conventions for document sources. If you have doubts about whether or not you are using your own or others’ writing ethically and legally, ask your instructor. • Plagiarism is misrepresenting someone else’s work as your own, taking someone else’s writing or ideas and passing them off as your own work. Plagiarism refers to stealing ideas as well as words, while copyright refers only to exact expression. Some acts of plagiarism are also copyright violations, but some are not. Some acts of plagiarism are covered by law (e.g., copyright violations), but other acts of plagiarism are a matter of institutional or professional or general ethics. • In academic contexts, plagiarism is regarded as an issue of academic honesty. Academic honesty refers to the ethics, codes, and guidelines under which the academic community does its learning, its teaching, its academic work. Those guidelines are important to the university’s being able to achieve its educational mission—its goals for teaching, learning, research, and service. How to avoid plagiarism Plagiarism can sometimes be the result of poor note taking, or paraphrasing without properly citing the reference. You can avoid plagiarism by: • citing your references • referencing correctly • recording direct quotes and paraphrases correctly when note taking. Quotes When you use the exact words, ideas or images of another person, you are quoting the author. If you do not use quotation marks around the original author's direct words and cite the reference, you are plagiarising. Paraphrasing Paraphrasing is when you take someone else's concepts and put them into your own words without changing the original meaning. Even though you are not using the same words you still need to state where the concepts came from. Note taking Poor note taking can lead to plagiarism. You should always take care to: • record all reference information correctly • use quotation marks exactly as in the original • paraphrase correctly • clearly distinguish your own ideas from the ideas of other authors and researchers. Plagiarism is when you take (i) somebody else’s idea, or (ii) somebody else’s words, and use them such that you appear to be the original creator or author of the idea or words. Even if you change a few words of someone else's sentence, it is still plagiarism if the same idea is presented. Plagiarism is a form of academic misconduct that is prohibited by the Student Code of Conduct. Plagiarism is unacceptable in all academic work and all documents authored by you, including assignments and project reports. Since published documents are stored and accessed in public places, it is quite possible that a published paper, thesis or dissertation can be accused of plagiarism, perhaps years after it is published. When you write a thesis/dissertation that includes discussion of research results from other documents, plagiarism may creep in unintentionally. Therefore, it is particularly important that you recognize plagiarism and make special efforts to avoid it. Plagiarism can also have legal consequences. Because of the Berne copyright convention, virtually all published material (including on-line, internet material) should be considered to have copyright protection whether it has a copyright notice or not. Suggestions to help you avoid plagiarism: • Take notes when you read. Do not copy complete sentences unless you want to quote the sentence. • Wait some time (or a day) after you read the original source text to write your draft. • Don't draft your paper with the original source text (or a photocopy) open next to you. Use your notes. Go back to the source later to check something you are unsure of. You can certainly use other peoples' ideas and words in your writing, as long as you give them appropriate credit. There are established methods of giving credit to your source of ideas and words. This is discussed in the following section. January 12, 2006 Examples: • If you use exact words from another source, put quotation marks around them. Example: According to Derrisen (2004), "since the flow of liquids in open channels is not subject to any pressure other than the weight of the liquid and atmospheric pressure on the surface, the theoretical analysis can be much simpler." • It is not sufficient to use the citation alone if a direct quote is used. Incorrect example: Since the flow of liquids in open channels is not subject to any pressure other than the weight of the liquid and atmospheric pressure on the surface, the theoretical analysis can be much simpler (Derrisen, 2004). • Changing a few words is not sufficient, since copying the ‘writing style’ is also plagiarism. Either use your own words or quote it. Incorrect example: Liquid flow in open channels is subject to pressure from the weight of the liquid and atmospheric pressure; therefore, the theoretical analysis is much easier (Derrisen, 2004). • Quotes are not necessary if you just use the idea. However, a citation is still required. Warning: it is almost impossible to put a single sentence into your own words. This is why you should read and understand, then write from your notes. Acceptable example: Simple models can be developed for a liquid in open channel flow since it is driven only by atmospheric pressure and weight of the liquid (Derrisen, 2004). Note that the last part of the sentence is a fact (not an idea); one can only change the wording of a fact, not the fact itself! When you describe an experiment, the facts (e.g., specifications of a piece of equipment) will be the same for all students, but the word and sentence arrangements will be different. • Put the citation where it will best identify which information is derived from which source. Place the citation after a key word or phrase which suggests a citation is needed. If most or all of a paragraph is from one source, put the citation at the end of the topic sentence. Repeat the citation later if necessary to make the source of information clear. Examples: - In a study of gear mechanics (Brable, 2005) showed that... - Several of these studies identified the critical control parameter… - Heat transfer in regenerators have been modeled by finite difference method (Jurgel, 2001) and by finite element method (Mitchell, 1996, Templeton, 2003)…. Please note that it is the responsibility of the student to avoid plagiarism in theses and dissertations. Your advisor and thesis committee can help with suggestions, but only if you discuss specific instances of a potential problem. If you are concerned about the quality of your writing, you can take the help of others to proofread your thesis.

Nanogrids: An ultimate solution for creative energy aware buildings

Nanogrids are small microgrids, typically serving a single building or a single load. Navigant Research has developed its own definition of a nanogrid as being 100 kW for grid-tied systems and 5 kW for remote systems not interconnected with a utility grid. Nanogrids mimic the innovation that is rising up from the bottom of the pyramid and capturing the imagination of growing numbers of technology vendors and investment capital, particularly in the smart building and smart transportation spaces, says Navigant. In other ways, nanogrids are more conventional than microgrids since they do not directly challenge utilities in the same way. Nanogrids are restricted to a single building or a single load, and therefore do not bump up against regulations prohibiting the transfer or sharing of power across a public right-of-way. From a technology point of view, perhaps the most radical idea behind nanogrids is a clear preference for direct current (DC) solutions, whether these systems are connected to the grid or operate as standalone systems, according to Navigant. building is often only as intelligent as the electrical distribution network it connects with. That's why smart buildings are often seen as an extension of the smart grid. Meters, building controls, intelligent lighting and HVAC systems, distributed energy systems and the software layered on top are indeed valuable for controlling localized energy use within a building. But in many cases, the building relies on the utility or regional electricity grid to value those services. Some analysts define these technologies as the "enterprise smart grid" because of their interaction with the electricity network. But what if there were no supporting centralized grid? How would buildings be designed then? In today's grid-centric framework, the building works for the benefit of the larger grid. But Nordman thinks there's a future where the opposite is true. And that future is the nanogrid. A nanogrid is different from a microgrid, according to the authors. Although some microgrids can be developed for single buildings, they mostly interface with the utility. Some aren't even fully islandable. A nanogrid, however, would be "indifferent to whether a utility grid is present." Rather, it would be a mostly autonomous DC-based system that would digitally connect individual devices to one other, as well as to power generation and storage within the building. Nordman and Christensen describe it this way: "A nanogrid is a single domain of power -- for voltage, capacity, reliability, administration, and price. Nanogrids include storage internally; local generation operates as a special type of nanogrid. A building-scale microgrid can be as simple as a network of nanogrids, without any central entity." The nanogrid is conceptually similar to an automobile or aircraft, which both house their own isolated grid networks powered by batteries that can support electronics, lighting and internet communications. Uninterruptible power supplies also perform a similar function in buildings during grid disturbances. Here's a simple diagram illustrating how a nanogrid -- based on the concept of "local power distribution" -- would function. Essentially, it would allow most devices to plug into power sockets and connect to the nanogrid, which could balance supply with demand from those individual loads.

Reverse Engineering: An nontraditional way of Engineering

Engineering is the profession involved in designing, manufacturing, constructing, and maintaining of products, systems, and structures. At a higher level, there are two types of engineering: forward engineering and reverse engineering. Forward engineering is the traditional process of moving from high-level abstractions and logical designs to the physical implementation of a system. In some situations, there may be a physical part without any technical details, such as drawings, bills-of-material, or without engineering data, such as thermal and electrical properties. The process of duplicating an existing component, subassembly, or product, without the aid of drawings, documentation, or computer model is known as reverse engineering. Reverse engineering can be viewed as the process of analyzing a system to: 1. Identify the system's components and their interrelationships 2. Create representations of the system in another form or a higher level of abstraction 3. Create the physical representation of that system Reverse engineering is very common in such diverse fields as software engineering, entertainment, automotive, consumer products, microchips, chemicals, electronics, and mechanical designs. For example, when a new machine comes to market, competing manufacturers may buy one machine and disassemble it to learn how it was built and how it works. A chemical company may use reverse engineering to defeat a patent on a competitor's manufacturing process. In civil engineering, bridge and building designs are copied from past successes so there will be less chance of catastrophic failure. In software engineering, good source code is often a variation of other good source code. In some situations, designers give a shape to their ideas by using clay, plaster, wood, or foam rubber, but a CAD model is needed to enable the manufacturing of the part. As products become more organic in shape, designing in CAD may be challenging or impossible. There is no guarantee that the CAD model will be acceptably close to the sculpted model. Reverse engineering provides a solution to this problem because the physical model is the source of information for the CAD model. This is also referred to as the part-to-CAD process. Another reason for reverse engineering is to compress product development times. In the intensely competitive global market, manufacturers are constantly seeking new ways to shorten lead-times to market a new product. Rapid product development (RPD) refers to recently developed technologies and techniques that assist manufacturers and designers in meeting the demands of reduced product development time. For example, injection-molding companies must drastically reduce the tool and die development times. By using reverse engineering, a three-dimensional product or model can be quickly captured in digital form, re-modeled, and exported for rapid prototyping/tooling or rapid manufacturing. Following are reasons for reverse engineering a part or product: 1. The original manufacturer of a product no longer produces a product 2. There is inadequate documentation of the original design 3. The original manufacturer no longer exists, but a customer needs the product 4. The original design documentation has been lost or never existed 5. Some bad features of a product need to be designed out. For example, excessive wear might indicate where a product should be improved 6. To strengthen the good features of a product based on long-term usage of the product 7. To analyze the good and bad features of competitors' product 8. To explore new avenues to improve product performance and features 9. To gain competitive benchmarking methods to understand competitor's products and develop better products 10. The original CAD model is not sufficient to support modifications or current manufacturing methods 11. The original supplier is unable or unwilling to provide additional parts 12. The original equipment manufacturers are either unwilling or unable to supply replacement parts, or demand inflated costs for sole-source parts 13. To update obsolete materials or antiquated manufacturing processes with more current, less-expensive technologies Reverse engineering enables the duplication of an existing part by capturing the component's physical dimensions, features, and material properties. Before attempting reverse engineering, a well-planned life-cycle analysis and cost/benefit analysis should be conducted to justify the reverse engineering projects. Reverse engineering is typically cost effective only if the items to be reverse engineered reflect a high investment or will be reproduced in large quantities. Reverse engineering of a part may be attempted even if it is not cost effective, if the part is absolutely required and is mission-critical to a system. Reverse engineering of mechanical parts involves acquiring three-dimensional position data in the point cloud using laser scanners or computed tomography (CT). Representing geometry of the part in terms of surface points is the first step in creating parametric surface patches. A good polymesh is created from the point cloud using reverse engineering software. The cleaned-up polymesh, NURBS (Non-uniform rational B-spline) curves, or NURBS surfaces are exported to CAD packages for further refinement, analysis, and generation of cutter tool paths for CAM. Finally, the CAM produces the physical part. It can be said that reverse engineering begins with the product and works through the design process in the opposite direction to arrive at a product definition statement (PDS). In doing so, it uncovers as much information as possible about the design ideas that were used to produce a particular product.

Electrical Power Quality issues and implications

Ideally, the best electrical supply would be a constant magnitude and frequency sinusoidal voltage waveform. However, because of the non-zero impedance of the supply system, of the large variety of loads that may be encountered and of other phenomena such as transients and outages, the reality is often different. The Power Quality of a system expresses to which degree a practical supply system resembles the ideal supply system.  If the Power Quality of the network is good, then any loads connected to it will run satisfactory and efficiently. Installation running costs and carbon footprint will be minimal.  If the Power Quality of the network is bad, then loads connected to it will fail or will have a reduced lifetime, and the efficiency of the electrical installation will reduce. Installation running costs and carbon footprint will be high and/or operation may not be possible at all. COST OF POOR POWER QUALITY Poor Power Quality can be described as any event related to the electrical network that ultimately results in a financial loss. Possible consequences of poor Power Quality include (Fig. 1):  Unexpected power supply failures (breakers tripping, fuses blowing).  Equipment failure or malfunctioning  Equipment overheating (transformers, motors, …) leading to their lifetime reduction.  Damage to sensitive equipment (PC‟s, production line control systems, …).  Electronic communication interferences.  Increase of system losses.  Need to oversize installations to cope with additional electrical stress with consequential increase of installation and running costs and associated higher carbon footprint.  Penalties imposed by utilities because the site pollutes the supply network too much.  Connection refusal of new sites because the site would pollute the supply network too much.  Impression of unsteadiness of visual sensation induced by a light stimulus whose luminance or spectral distribution fluctuates with time (flicker)  Health issues with and reduced efficiency of personnel,.. The following main contributors to Low Voltage poor Power Quality can be defined:  Reactive power, as it loads up the supply system unnecessary,  Harmonic pollution, as it causes extra stress on the networks and makes installations run less efficiently,  Load imbalance, especially in office building applications, as the unbalanced loads may result in excessive voltage imbalance causing stress on other loads connected to the same network, and leading to an increase of neutral current and neutral to earth voltage build-up,  Fast voltage variations leading to flicker. All this phenomena potentially lead to inefficient running of installations, system down time and reduced equipment life and consequently high installation running costs. In addition to financial loss due to „production stops‟, another factor of the cost of poor Power Quality can be identified by analyzing the extra kWh losses that exist due to the presence of harmonic pollution in typical network components such as transformers, cables and motors. As this loss has to be supplied by the utility power plants, a financial loss and CO2 emissions can be assigned to it. Exact values of this loss depend on the local situation of kWh tariffs and ways that the electrical power is generated (e.g. 3 nuclear power plants have almost no CO2 footprint per kWh generated as opposed to coal power plants for which the footprint is large at around 900-1000 g/kWh produced. Most harmonic pollution nowadays is created as harmonic current produced by loads in individual installations. This harmonic current, injected into the network impedance transfers into harmonic voltage, (Ohm‟s law); which gets applied to all the loads within that user‟s installation. As a result the user employing harmonic loads may suffer from Power Quality problems. In addition however, the harmonic current produced in one installation if not filtered is also flowing through the feeding transformers into the utility supply and creates harmonic voltage distortion on the public network too. As a result, any utility user connected to the same supply will become affected by the pollution created by another utility customer and could suffer operational consequences in his own installation due to this. In order to limit this type of problems most utilities have adopted Power Quality standards/regulations that shall be respected by the users of the supply network. In extreme cases, non-compliance with these regulations leads to a connection refusal of a new installation, which in turn can have a significant impact on the production and revenue loss of the company. POWER QUALITY PARAMETERS (TERMINOLOGY) Reactive power and power factor (cos  In an AC supply, the current is often phase-shifted from the supply voltage. This leads to different power definitions: The active power P [kW], which is responsible of the useful work, is associated with the portion of the current which is in phase with the voltage. - The reactive power Q [kvar], which sustains the electromagnetic field used to make e.g. a motor operate is an energy exchange (per unit of time) between reactive components of the electrical system (capacitors and reactors). It is associated with the portion of the current which is phase shifted by 90° with the voltage. - The apparent power S [kVA], which gives a geometrical combination of the active and of the reactive powers, can be seen as the total power drawn from the network. The ratio between the active power and the apparent power if often referred to as the displacement power factor or cos , and gives a measure of how efficient the utilization of the electrical energy is. A cos that equals to 1 refers to the most efficient transfer of useful energy. A cos that equals to 0 refers to the most inefficient way of transferring useful energy. Harmonic distortion The harmonic pollution is often characterized by the Total Harmonic Distortion or THD which is by definition equal to the ratio of the RMS harmonic content to the fundamental. Voltage unbalance In the symmetrical components theory Fortescue has shown that any three phase system can be expressed as the sum of three symmetrical sets of balanced phasors: the first set having the same phase sequence as the initial system (positive phase sequence), the second set having the inverse phase sequence (negative phase sequence) and the third one consisting of three phasors in phase (zero phase sequence or homopolar components). A normal three phase supply has the three phases of same magnitude but with a phase shifted by 120°. Any deviation (magnitude or phase) of one of the three signals will result in a negative phase sequence component and/or a zero phase sequence component. Flicker According to the International Electrotechnical Vocabulary (IEV) [4] of the International Electrotechnical Committee (IEC), flicker is defined as 'Impression of unsteadiness of visual sensation induced by a light stimulus whose luminance or spectral distribution fluctuates with time'. From a more practical point of view one can say that voltage fluctuations on the supply network cause change of the luminance of lamps, which in turn can create the visual phenomenon called flicker. While a small flicker level may be acceptable, above a certain threshold it becomes annoying to people present in a room where the flicker exists. The degree of annoyance grows very rapidly with the amplitude of the fluctuation. Further on, at certain repetition rates of the voltage fluctuation, even small fluctuation amplitudes can be annoying. REGULATIONS Utility regulations for harmonic pollution are often based on internationally recognized work undertaken by reputable independent bodies which have defined maximum allowable distortion limits for proper operation of equipment. Commonly quoted examples of such documents targeting harmonic pollution. In general the principle of the regulations is as follows:  Limit the total voltage distortion (THDV) contribution that can be created by a customer. In this it is taken into account that if the totally accepted level of voltage distortion is e.g. 5% (of the fundamental voltage), this limit has to be divided over all the users connected. Possibly limits are also imposed for individual harmonic voltage components (e.g. 3% maximum limit for individual harmonic voltages).  Convert the voltage distortion limits into current limits which are accepted to flow into the supply system. The current limits can then be easily verified through measurement.

Modelling and Simulation: For Engineering project

Modelling and Simulation Model: A system of postulates, data and interfaces presented as a mathematical description of an entity or proceedings or state of affair. (Development of equations, constraints and logic rules) Simulation: Exercising the model and obtaining results. (Implementation of the model) Simulation has emerged as the Third methodology of exploring the truth. It would complement the theory and experimental methodology. Simulation will never replace them. Simulations are applicable in the following situations: 1. When operating conditions change e.g. temperature, pressure, etc 2. When non-controllable factors change e.g. weather, earthquake 3. Dependence of variation of critical factors e.g. fatigue, resonance may be destructive. 4. How sensitive is one factor to the changes in another? 5. Other benefits: a) Useful in design b) Study effects of constraints c) Increase understanding 6. Pitfalls: An assumption, which the owner can’t model or verbalise; so when two independent models clash, contradictory results arise Advantages of simulation Saves manpower, material Useful even if not possible by other means Saves money with fast, consistent answers Could be used for education after establishing Increased flexibility, accuracy, range of operation New results not available before Improved results due to standardization Increased understanding Explicitly stated assumptions and constraint Requirements/ skill required Computer Skill/Expertise Time for implementation Drawbacks: Modelling errors at different levels – Scientific model of reality – Mathematical model – Discrete numerical model – Application program model – Computational model Input errors: Out of range inputs can give spurious results Precision errors: Limits in the precision Phases of development of simulation model Real system to mathematical model Algorithm to solve mathematical model Implementation on a computer Validation – User with I/O – Model – Evaluations Simulation

Electric Braking: Merits and applications

Induction motors are used at various places. Speed control of induction motors is quite difficult and that’s why their use was restricted and DC motors had to be used as their speed regulation was possible. But when induction motor drives were invented and implemented, they were given preference because of many advantages over DC motors. Whenever controlling of motors is done, braking is the most important term, so as with induction motors. Induction motor braking can be done by different methods, which are i. Regenerative braking of induction motor ii. Plugging Braking of induction motor iii. Dynamic braking of induction motor is further categorized as a) AC dynamic breaking b) Self excited braking using capacitors c) DC dynamic braking d) Zero Sequence braking We know the power (input) of an induction motor is given as. Pin = 3VIscosφs Here, φs the phase angle between stator phase voltage V and the stator phase current Is. Now, for motoring operation φs < 90° and for braking operation φs > 90°. When the speed of the motor is more than the synchronous speed, relative speed between the motor conductors and air gap rotating field reverses, as a result the phase angle because greater than 90° and the power flow reverse and thus regenerative braking takes place. The nature of the speed torque curves are shown in the figure beside. It the source frequency is fixed then the regenerative braking of induction motor can only take place if the speed of the motor is greater than synchronous speed, but with a variable frequency source regenerative braking of induction motor can occur for speeds lower than synchronous speed. The main advantage of this kind of braking can be said that the generated power is use fully employed and the main disadvantage of this type of braking is that for fixed frequency sources, braking cannot happen below synchronous speeds. When the rotor of an induction motor turns slower than the speed set by the applied frequency, the motor is transforming electrical energy into mechanical energy at the motor shaft. This process is referred to as ‘motoring’. When the rotor turns faster than the synchronous speed set by a drive output, the motor is transforming mechanical energy from the motor shaft into electrical energy. It may be a ramp to stop, a reduction in commanded speed or an overhauling load that causes the shaft speed to be greater than the synchronous speed. In any case this, condition is referred to as ‘regeneration”. Essentially, mechanical energy is converted to electrical energy. The case is much the same for a DC drive and motor. The increase in DC voltage for the DC drive occurs at the armature connection. Some DC drives have not only a forward but also a reverse bridge. The reverse bridge allows the DC energy from the armature to be transferred to the utility line. If the DC drive has only the forward bridge, a shunt regulator can be used in parallel with the armature to dissipate this energy into heat. For an AC drive and motor in a regenerative condition, the AC power from the motor flows backward through the inverter bridge diodes shown in figure 1 below. On most AC drives, utility power is first converted into DC by a diode or SCR rectifier bridge These bridges are very cost effective, but only handle power in the “motoring” direction. Dynamic brake or Chopper – What’s the difference? From an electrical stand point they both do the same thing. The major difference is in the construction. Dynamic brakes have the controller, switching device and resistor housed in one self contained unit. It is rated in horsepower and has only a 20% duty cycle rating. A chopper contains only the regulator circuit and switching device and is rated in amps. The resistors are treated as a separate component. This gives the user several advantages. First, the resistors can be accurately sized for a given application. Also, the chopper module can be mounted in an enclosure while the resistor, with the large amount of heat energy to dissipate, can be remotely mounted up to 100 feet away. A close look at the application is needed before a decision to use a brake or chopper is made. Some rotational and linear loads with a low regenerative duty cycle can be handled with a brake while overhauling loads, and loads with a duty cycle greater than 20% are more suited to a chopper. In general, the chopper is a more “heavy duty” solution. Exceeding the 20% duty cycle rating, a condition that may be tough to prove after the fact causes many dynamic brake failures. Another avoidable cause of failure for dynamic brakes and choppers that warrants mention is misconnection. These devices need to be connected at the capacitor bank nodes of the DC bus. Many drives also provide a DC bus connection point at the input bridge rectifier nodes. Applications Electrical drive systems are being used more and more on ships, oil rigs, crane barges and offshore vessels of all types, for every type of powered application: main propellors and bow thrusters, driving winches and windlasses, cranes, lifts, conveyors and jacks, cable laying and tensioning. Advantages of electric braking An important benefit from using an electric drive is that reliable systems of regenerative and dynamic braking resistors are available to complement or replace traditional mechanical braking systems. The advantages of electric braking include control, reliability, mechanical simplicity, weight saving and in some cases the opportunity to make use of the regenerated braking energy. Range Cressall Resistors’ wide range of resistor technologies and long experience in this field means that we have suitable brake resistor designs for all of the above applications, with braking powers from a few kW up to many MW (needed, for example, for some crane and main propulsion brakes) and cooling methods which include liquid, forced air and natural convection. We have standard products of all types. Design considerations The majority of our designs make use of suitably rated Incoloy-sheathed mineral insulated elements. These are less vulnerable to physical damage, prevent accidental contact with live, possibly high voltages, and are thus considered much safer to use in these environments.

Engineering projects: Research and consultancy for programming, Physical modelling and simulation, Report publishing

MATLAB® is a high-performance technical computing language. It has an incredibly rich variety of functions and is often referred to as the Bible due to its vast programming capabilities. In MATLAB, computation, visualization, and programming are integrated such that the data can be expressed in a familiar mathematical notation. Evolved over many years with constant inputs from various users, it is now being widely used as a programming language for scientific and technical computation. One can perform powerful operations in MATLAB by using simple commands. Hence, writing programs in MATLAB is easier compared to other high-level languages such as FORTRAN or C. Users can even build their own set of functions for a particular application. It is an interactive system in which the basic data element is an array. MATLAB is used as a standard tool in various introductory and advanced courses of almost all streams of engineering. It is used as a tool for analysis, modeling and simulation, and for high productive research and development activities. It can be used for various functions such as mathematical computation, algorithm development, data acquisition, modeling, simulation, prototyping, data analysis, exploration, visualization, and engineering graphics development as well as building graphical user interface. SIMULINK is a software package for modeling, simulating, and analysing dynamic systems. MATLAB and SIMULINK are integrated and one can simulate, analyse, or revise the models in either environment. MATLAB also features a family of add-on application-specific features called toolboxes in SIMULINK. These toolboxes can be used for modeling and simulation of specialized technology in a real-time environment. This book attempts to train engineering students of different streams to use the functions and toolboxes of MATLAB and SIMULINK for the study, design, and analysis of different electrical circuits and systems. All these toolboxes can be used to build a real-time prototype of the system. Here you will directly speak to the expert, find a solution to your need or problem and save your valuable time and effort for future end-overs. Genuine advice and consultancy regarding an engineering project is provided here on reasonable consultant charges. The expert himself has vast experience of 15 years and has executed more than 500+ projects at various international universities as a professional.Also for some selected projects report can also be provided on reasonable charges on request.

Switch Reluctance Motor drive for real time applications

The switched reluctance motor (SRM) is a type of a stepper motor, an electric motor that runs by reluctance torque. Unlike common DC motor types, power is delivered to windings in the stator (case) rather than the rotor. This greatly simplifies mechanical design as power does not have to be delivered to a moving part, but it complicates the electrical design as some sort of switching system needs to be used to deliver power to the different windings. With modern electronic devices, precisely timed switching is not a problem, and the SRM (Switched Reluctance Motor) is a popular design for modern stepper motors. Its main drawback is torque ripple. An alternate use of the same mechanical design is as a generator when driven mechanically, and the load is switched to the coils in sequence to synchronize the current flow with the rotation. Such generators can be run at much higher speeds than conventional types as the armature can be made as one piece of magnetisable material, a simple slotted cylinder . In this case use of the abbreviation SRM is extended to mean Switched Reluctance Machine, although SRG, Switched Reluctance Generator is also used. A topology that is both motor and generator is useful for starting the prime mover, as it saves a dedicated starter motor. The synchronous reluctance motor has many advantages over other ac motors. For example, its structure is simple and rugged. In addition, its rotor does not have any winding or magnetic material. Prior to twenty years ago, the SynRM was regarded as inferior to other types of ac motors due to its lower average torque and larger torque pulsation. Recently, many researchers have proposed several methods to improve the performance of the motor and drive system. In fact, the SynRM has been shown to be suitable for ac drive systems for several reasons. For example, it is not necessary to compute the slip of the SynRM as it is with the induction motor. As a result, there is no parameter sensitivity problem. In addition, it does not require any permanent magnetic material as the permanent synchronous motor does. The sensorless drive is becoming more and more popular for synchronous reluctance motors. The major reason is that the sensorless drive can save space and reduce cost. Generally speaking, there are two major methods to achieve a sensorless drive system: vector control and direct torque control. Although most researchers focus on vector control for a sensorless synchronous reluctance drive, direct torque control is simpler. By using direct torque control, the plane of the voltage vectors is divided into six or twelve sectors. Then, an optimal switching strategy is defined for each sector. The purpose of the direct torque control is to restrict the torque error and the stator flux error within given hysteresis bands. After executing hysteresis control, a switching pattern is selected to generate the required torque and flux of the motor. A closed-loop drive system is thus obtained. The SRM has wound field coils as in a DC motor for the stator windings. The rotor however has no magnets or coils attached. It is a solid salient-pole rotor (having projecting magnetic poles) made of soft magnetic material (often laminated-steel). When power is applied to the stator windings, the rotor's magnetic reluctance creates a force that attempts to align the rotor pole with the nearest stator pole. In order to maintain rotation, an electronic control system switches on the windings of successive stator poles in sequence so that the magnetic field of the stator "leads" the rotor pole, pulling it forward. Rather than using a troublesome high-maintenance mechanical commutator to switch the winding current as in traditional motors, the switched-reluctance motor uses an electronic position sensor to determine the angle of the rotor shaft and solid state electronics to switch the stator windings, which also offers the opportunity for dynamic control of pulse timing and shaping. This differs from the apparently similar induction motor which also has windings that are energized in a rotating phased sequence, in that the magnetization of the rotor is static (a salient pole that is made 'North' remains so as the motor rotates) while an induction motor has slip, and rotates at slightly less than synchronous speed. This absence of slip makes it possible to know the rotor position exactly, and the motor can be stepped arbitrarily slowly.

BLDC motor Drive and applications in real time systems

Before there were brushless DC motors there were brush DC motors, which were brought on in part to replace the less efficient AC induction motors that came before. The brush DC motor was invented all the way back in 1856 by famed German inventor and industrialist Ernst Werner von Siemens. Von Siemens is so famous that the international standard unit of electrical conductance is named after him. Von Siemens studied electrical engineering after leaving the army and produced many contributions to the world of electrical engineering, including the first electric elevator in 1880. Von Siemens’s brush DC motor was fairly rudimentary and was improved upon by Harry Ward Leonard, who nearly perfected the first effective motor control system near the end of the 19th century. This system used a rheostat to control the current in the field winding, which resulted in adjusting the output voltage of the DC generator, which in turn adjusted the motor speed. The Ward Leonard system remained in place all the way until 1960, when the Electronic Regulator Company’s thyristor devices produced solid state controllers that could convert AC power to rectified DC power more directly. It supplanted the Ward Leonard system due to its simplicity and efficiency. Advent of Brushless DC Motors Once the Electronic Regulator Company maximized the efficiency of the brush DC motor, the door was opened for an even more efficient motor device. Brushless DC motors first made the scene in 1962, when T.G. Wilson and P.H. Trickey unveiled what they called “a DC machine with solid state commutation.” Remember that the key element of brushless DC motors as opposed to brush DC motors is that the brushless DC motor requires no physical commutator, a revolutionary difference. As the device was refined and developed, it became a popular choice for special applications such as computer disk drives, robotics and in aircraft. In fact, brushless DC motors are used in these devices today, fifty years later, so great is their effectiveness. The reason these motors were such a great choice for these devices is that in these devices brush wear was a big problem, either because of the intense demands of the application or, for example, in the case of aircraft because of low humidity. Because brushless DC motors had no brushes that could wear out, they represented a great leap forward in technology for these types of devices. The problem was that as reliable as they were, these early brushless DC motors were not able to generate a great deal of power. Modern Brushless DC Motors That all changed in the 1980s, when permanent magnet materials became readily available. The use of permanent magnets, combined with high voltage transistors, enabled brushless DC motors to generate as much power as the old brush DC motors, if not more. Near the end of the 1980s, Robert E. Lordo of the POWERTEC Industrial Corporation unveiled the first large brushless DC motors, which had at least ten times the power of the earlier brushless DC motors. Today, there are probably no major motor manufacturers that do not produce brushless DC motors capable of high power jobs. Naturally, NMB Tech offers a wide variety of brushless DC motors for you to choose from, in sizes from 15mm in diameter to 65mm in diameter, from 0.7 maximum Watts output to 329.9. If you’re starting a new project that requires motors for its applications, you’ll want to seriously consider using brushless DC motors. Industries with motor needs have relied on brushless DC motors for nearly fifty years, and there is every reason to believe that they will continue to do so for decades to come. Take a look at some brushless DC motors today. The brushless DC (BLDC) motor can be envisioned as a brush DC motor turned inside out, where the permanent magnets are on the rotor, and the windings are on the stator. As a result, there are no brushes and commutators in this motor, and all of the disadvantages associated with the sparking of brush DC motors are eliminated. This motor is referred to as a "DC" motor because its coils are driven by a DC power source which is applied to the various stator coils in a predetermined sequential pattern. This process is known as commutation. However, "BLDC" is really a misnomer, since the motor is effectively an AC motor. The current in each coil alternates from positive to negative during each electrical cycle. The stator is typically a salient pole structure which is designed to produce a trapezoidal back-EMF waveshape which matches the applied commutated voltage waveform as closely as possible. However, this is very hard to do in practice, and the resulting back-EMF waveform often looks more sinusoidal than trapezoidal. For this reason, many of the control techniques used with a PMSM motor (such as Field Oriented Control) can equally be applied to a BLDC motor. Another misconception about the BLDC motor is related to how it is driven. Unlike an open-loop stepper application where the rotor position is determined by which stator coil is driven, in a BLDC motor, which stator coil is driven is determined by the rotor position. The stator flux vector position must be synchronized to the rotor flux vector position (not the other way around) in order to obtain smooth operation of the motor. In order to accomplish this, knowledge of the rotor position is required in order to determine which stator coils to energize. Several techniques exist to do this, but the most popular technique is to monitor the rotor position using hall-effect sensors. Unfortunately, these sensors and their associated connectors and harnesses result in increased system cost, and reduced reliability. In an effort to mitigate these issues, several techniques have been developed to eliminate these sensors, resulting in sensorless operation. Most of these techniques are based upon extracting position information from the back-EMF waveforms of the stator windings while the motor is spinning. However, techniques based on back-EMF sensing fall apart when the motor is spinning slowly or at a standstill, since the back-EMF waveforms are faint or non-existent. As a result, new techniques are constantly being developed which obtain rotor position information from other signals at low or zero speed. BLDC motors reign supreme in efficiency ratings, where values in the mid-nineties percent range are routinely obtained. Current research into new amorphous core materials is pushing this number even higher. Ninety six percent efficiency in the 100W range has been reported. They also compete for the title of fastest motor in the world, with speeds on some motors achieving several hundred thousand RPM (400K RPM reported in one application). The most common BLDC motor topology utilizes a stator structure consisting of three phases. As a result, a standard 6-transistor inverter is the most commonly used power stage, as shown in the diagram. Depending on the operational requirements (sensored vs. sensorless, commutated vs. sinusoidal, PWM vs. SVM, etc.) there are many different ways to drive the transistors to achieve the desired goal, which are too numerous to cover here. This places a significant requirement on the flexibility of the PWM generator, which is typically located in the microcontroller.

Smart grid future grid for power distribution and monitoring

A smart grid is a modernized electrical grid that uses analog or digital information and communications technology to gather and act on information - such as information about the behaviors of suppliers and consumers - in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity. Electronic power conditioning and control of the production and distribution of electricity are important aspects of the smart grid. “Smart grid” generally refers to a class of technology people are using to bring utility electricity delivery systems into the 21st century, using computer-based remote control and automation. These systems are made possible by two-way communication technology and computer processing that has been used for decades in other industries. They are beginning to be used on electricity networks, from the power plants and wind farms all the way to the consumers of electricity in homes and businesses. They offer many benefits to utilities and consumers -- mostly seen in big improvements in energy efficiency on the electricity grid and in the energy users’ homes and offices. For a century, utility companies have had to send workers out to gather much of the data needed to provide electricity. The workers read meters, look for broken equipment and measure voltage, for example. Most of the devices utilities use to deliver electricity have yet to be automated and computerized. Now, many options and products are being made available to the electricity industry to modernize it. The “grid” amounts to the networks that carry electricity from the plants where it is generated to consumers. The grid includes wires, substations, transformers, switches and much more. Much in the way that a “smart” phone these days means a phone with a computer in it, smart grid means “computerizing” the electric utility grid. It includes adding two-way digital communication technology to devices associated with the grid. Each device on the network can be given sensors to gather data (power meters, voltage sensors, fault detectors, etc.), plus two-way digital communication between the device in the field and the utility’s network operations center. A key feature of the smart grid is automation technology that lets the utility adjust and control each individual device or millions of devices from a central location. Features of the smart grid The smart grid represents the full suite of current and proposed responses to the challenges of electricity supply. Because of the diverse range of factors there are numerous competing taxonomies and no agreement on a universal definition. Nevertheless, one possible categorisation is given here. Reliability The smart grid will make use of technologies, such as state estimation, that improve fault detection and allow self-healing of the network without the intervention of technicians. This will ensure more reliable supply of electricity, and reduced vulnerability to natural disasters or attack. Although multiple routes are touted as a feature of the smart grid, the old grid also featured multiple routes. Initial power lines in the grid were built using a radial model, later connectivity was guaranteed via multiple routes, referred to as a network structure. However, this created a new problem: if the current flow or related effects across the network exceed the limits of any particular network element, it could fail, and the current would be shunted to other network elements, which eventually may fail also, causing a domino effect. See power outage. A technique to prevent this is load shedding by rolling blackout or voltage reduction (brownout). The economic impact of improved grid reliability and resilience is the subject of a number of studies and can be calculated using a US DOE funded methodology for US locations using at least one calculation tool. Flexibility in network topology Next-generation transmission and distribution infrastructure will be better able to handle possible bidirection energy flows, allowing for distributed generation such as from photovoltaic panels on building roofs, but also the use of fuel cells, charging to/from the batteries of electric cars, wind turbines, pumped hydroelectric power, and other sources. Classic grids were designed for one-way flow of electricity, but if a local sub-network generates more power than it is consuming, the reverse flow can raise safety and reliability issues.[14] A smart grid aims to manage these situations.] Efficiency Numerous contributions to overall improvement of the efficiency of energy infrastructure are anticipated from the deployment of smart grid technology, in particular including demand-side management, for example turning off air conditioners during short-term spikes in electricity price, reducing the voltage when possible on distribution lines through Voltage/VAR Optimization (VVO), eliminating truck-rolls for meter reading, and reducing truck-rolls by improved outage management using data from Advanced Metering Infrastructure systems. The overall effect is less redundancy in transmission and distribution lines, and greater utilization of generators, leading to lower power prices. Load adjustment/Load balancing The total load connected to the power grid can vary significantly over time. Although the total load is the sum of many individual choices of the clients, the overall load is not a stable, slow varying, increment of the load if a popular television program starts and millions of televisions will draw current instantly. Traditionally, to respond to a rapid increase in power consumption, faster than the start-up time of a large generator, some spare generators are put on a dissipative standby mode. A smart grid may warn all individual television sets, or another larger customer, to reduce the load temporarily (to allow time to start up a larger generator) or continuously (in the case of limited resources). Using mathematical prediction algorithms it is possible to predict how many standby generators need to be used, to reach a certain failure rate. In the traditional grid, the failure rate can only be reduced at the cost of more standby generators. In a smart grid, the load reduction by even a small portion of the clients may eliminate the problem. Peak curtailment/leveling and time of use pricing To reduce demand during the high cost peak usage periods, communications and metering technologies inform smart devices in the home and business when energy demand is high and track how much electricity is used and when it is used. It also gives utility companies the ability to reduce consumption by communicating to devices directly in order to prevent system overloads. Examples would be a utility reducing the usage of a group of electric vehicle charging stations or shifting temperature set points of air conditioners in a city. To motivate them to cut back use and perform what is called peak curtailment or peak leveling, prices of electricity are increased during high demand periods, and decreased during low demand periods.[7] It is thought that consumers and businesses will tend to consume less during high demand periods if it is possible for consumers and consumer devices to be aware of the high price premium for using electricity at peak periods. This could mean making trade-offs such as cycling on/off air conditioners or running dishes at 9 pm instead of 5 pm. When businesses and consumers see a direct economic benefit of using energy at off-peak times, the theory is that they will include energy cost of operation into their consumer device and building construction decisions and hence become more energy efficient. According to proponents of smart grid plans, this will reduce the amount of spinning reserve that electric utilities have to keep on stand-by, as the load curve will level itself through a combination of "invisible hand" free-market capitalism and central control of a large number of devices by power management services that pay consumers a portion of the peak power saved by turning their device off.. Sustainability The improved flexibility of the smart grid permits greater penetration of highly variable renewable energy sources such as solar power and wind power, even without the addition of energy storage. Current network infrastructure is not built to allow for many distributed feed-in points, and typically even if some feed-in is allowed at the local (distribution) level, the transmission-level infrastructure cannot accommodate it. Rapid fluctuations in distributed generation, such as due to cloudy or gusty weather, present significant challenges to power engineers who need to ensure stable power levels through varying the output of the more controllable generators such as gas turbines and hydroelectric generators. Smart grid technology is a necessary condition for very large amounts of renewable electricity on the grid for this reason. Market-enabling The smart grid allows for systematic communication between suppliers (their energy price) and consumers (their willingness-to-pay), and permits both the suppliers and the consumers to be more flexible and sophisticated in their operational strategies. Only the critical loads will need to pay the peak energy prices, and consumers will be able to be more strategic in when they use energy. Generators with greater flexibility will be able to sell energy strategically for maximum profit, whereas inflexible generators such as base-load steam turbines and wind turbines will receive a varying tariff based on the level of demand and the status of the other generators currently operating. The overall effect is a signal that awards energy efficiency, and energy consumption that is sensitive to the time-varying limitations of the supply. At the domestic level, appliances with a degree of energy storage or thermal mass (such as refrigerators, heat banks, and heat pumps) will be well placed to 'play' the market and seek to minimise energy cost by adapting demand to the lower-cost energy support periods. This is an extension of the dual-tariff energy pricing mentioned above. Demand response support Demand response support allows generators and loads to interact in an automated fashion in real time, coordinating demand to flatten spikes. Eliminating the fraction of demand that occurs in these spikes eliminates the cost of adding reserve generators, cuts wear and tear and extends the life of equipment, and allows users to cut their energy bills by telling low priority devices to use energy only when it is cheapest. Currently, power grid systems have varying degrees of communication within control systems for their high value assets, such as in generating plants, transmission lines, substations and major energy users. In general information flows one way, from the users and the loads they control back to the utilities. The utilities attempt to meet the demand and succeed or fail to varying degrees (brownout, rolling blackout, uncontrolled blackout). The total amount of power demand by the users can have a very wide probability distribution which requires spare generating plants in standby mode to respond to the rapidly changing power usage. This one-way flow of information is expensive; the last 10% of generating capacity may be required as little as 1% of the time, and brownouts and outages can be costly to consumers. Latency of the data flow is a major concern, with some early smart meter architectures allowing actually as long as 24 hours delay in receiving the data, preventing any possible reaction by either supplying or demanding devices. Platform for advanced services As with other industries, use of robust two-way communications, advanced sensors, and distributed computing technology will improve the efficiency, reliability and safety of power delivery and use. It also opens up the potential for entirely new services or improvements on existing ones, such as fire monitoring and alarms that can shut off power, make phone calls to emergency services, etc. Provision megabits, control power with kilobits, sell the rest The amount of data required to perform monitoring and switching one's appliances off automatically is very small compared with that already reaching even remote homes to support voice, security, Internet and TV services. Many smart grid bandwidth upgrades are paid for by over-provisioning to also support consumer services, and subsidizing the communications with energy-related services or subsidizing the energy-related services, such as higher rates during peak hours, with communications. This is particularly true where governments run both sets of services as a public monopoly. Because power and communications companies are generally separate commercial enterprises in North America and Europe, it has required considerable government and large-vendor effort to encourage various enterprises to cooperate. Some, like Cisco, see opportunity in providing devices to consumers very similar to those they have long been providing to industry.[18] Others, such as Silver Spring Networks or Google, are data integrators rather than vendors of equipment. While the AC power control standards suggest powerline networking would be the primary means of communication among smart grid and home devices, the bits may not reach the home via Broadband over Power Lines (BPL) initially but by fixed wireless. The number of applications that can be used on the smart grid once the data communications technology is deployed is growing as fast as inventive companies can create and produce them. Benefits include enhanced cyber-security, handling sources of electricity like wind and solar power and even integrating electric vehicles onto the grid. The companies making smart grid technology or offering such services include technology giants, established communication firms and even brand new technology firms.

Superconductivity applications in Power System Engineering

Superconductors differ fundamentally in quantum physics behavior from conventional materials in the manner by which electrons, or electric currents, move through the material. It is these differences that give rise to the unique properties and performance benefits that differentiate superconductors from all other known conductors. Unique Properties • Zero resistance to direct current • Extremely high current carrying density • Extremely low resistance at high frequencies • Extremely low signal dispersion • High sensitivity to magnetic field • Exclusion of externally applied magnetic field • Rapid single flux quantum transfer • Close to speed of light signal transmission Zero resistance and high current density have a major impact on electric power transmission and also enable much smaller or more powerful magnets for motors, generators, energy storage, medical equipment and industrial separations. Low resistance at high frequencies and extremely low signal dispersion are key aspects in microwave components, communications technology and several military applications. Low resistance at higher frequencies also reduces substantially the challenges inherent to miniaturization brought about by resistive, or I2 R, heating. The high sensitivity of superconductors to magnetic field provides a unique sensing capability, in many cases 1000x superior to today’s best conventional measurement technology. Magnetic field exclusion is important in multi-layer electronic component miniaturization, provides a mechanism for magnetic levitation and enables magnetic field containment of charged particles. The final two properties form the basis for digital electronics and high speed computing well beyond the theoretical limits projected for semiconductors. All of these materials properties have been extensively demonstrated throughout the world. In 1911, H. K. Onnes, a Dutch physicist, discovered superconductivity by cooling mercury metal to extremely low temperature and observing that the metal exhibited zero resistance to electric current. Prior to 1973 many other metals and metal alloys were found to be superconductors at temperatures below 23.2K. These became known as Low Temperature Superconductor (LTS) materials. Since the 1960s a Niobium-Titanium (Ni-Ti) alloy has been the material of choice for commercial superconducting magnets. More recently, a brittle Niobium-Tin intermetallic material has emerged as an excellent alternative to achieve even higher magnetic field strength. In 1986, J. G. Bednorz and K. A. Müller discovered 2 Superconductivity: Present and Future Applications © 2009 CCAS : Coalition for the Commercial Application of Superconductors oxide based ceramic materials that demonstrated superconducting properties as high as 35K. This was quickly followed in early 1997 by the announcement by C. W. Chu of a cuprate superconductor functioning above 77K, the boiling point of liquid nitrogen. Since then, extensive research worldwide has uncovered many more oxide based superconductors with potential manufacturability benefits and critical temperatures as high as 135K. A superconducting material with a critical temperature above 23.2K is known as a High Temperature Superconductor (HTS), despite the continuing need for cryogenic refrigeration for any application. Challenges • Cost • Refrigeration • Reliability • Acceptance Forty years of development and commercialization of applications involving LTS materials have demonstrated that a superconductor approach works best when it represents a unique solution to the need. Alternatively, as the cost of the superconductor will always be substantially higher than that of a conventional conductor, it must bring overwhelming cost effectiveness to the system. The advent of HTS has changed the dynamic of refrigeration by permitting smaller and more efficient system cooling for some applications. Design, integration of superconducting and cryogenic technologies, demonstration of systems cost benefits and long term reliability must be met before superconductivity delivers on its current promise of major societal benefits and makes substantial commercial inroads into new applications. About Superconductivity Superconductivity is widely regarded as one of the great scientific discoveries of the 20th Century. This miraculous property causes certain materials, at low temperatures, to lose all resistance to the flow of electricity. This state of “losslessness” enables a range of innovative technology applications. At the dawn of the 21st century, superconductivity forms the basis for new commercial products that are transforming our economy and daily life. Current Commercial Applications • Magnetic Resonance Imaging (MRI) • Nuclear Magnetic Resonance (NMR) • High-energy physics accelerators • Plasma fusion reactors • Industrial magnetic separation of kaolin clay The major commercial applications of superconductivity in the medical diagnostic, science and industrial processing fields listed above all involve LTS materials and relatively high field magnets. Indeed, without superconducting technology most of these applications would not be viable. Several smaller applications utilizing LTS materials have also been commercialized, e.g. research magnets and MagnetoEncephalograhy (MEG). The latter is based on Superconducting Quantum Interference Device (SQUID) technology which detects and measures the weak magnetic fields generated by the brain. The only substantive commercial products incorporating HTS materials are electronic filters used in wireless base stations. About 10,000 units have been installed in wireless networks worldwide to date. More detail on these applications is presented in subsequent sections. Emerging Applications Superconductor-based products are extremely environmentally friendly compared to their conventional counterparts. They generate no greenhouse gases and are cooled by non-flammable liquid nitrogen (nitrogen comprises 80% of our atmosphere) as opposed to conventional oil coolants that are both flammable and toxic. They are also typically at least 50% smaller and lighter than equivalent conventional units which translates into economic incentives. These benefits have given rise to the ongoing development of many new applications in the following sectors: Electric Power. Superconductors enable a variety of applications to aid our aging and heavily burdened electric power infrastructure - for example, in generators, transformers, underground cables, synchronous condensers and fault current limiters. The high power density and electrical efficiency of superconductor wire results in highly compact, powerful devices and systems that are more reliable, efficient, and environmentally benign. Transportation. The rapid and efficient movement of people and goods, by land and by sea, poses important logistical, environmental, land use and other challenges. Superconductors are enabling a new generation of transport technologies including ship propulsion systems, magnetically levitated trains, and railway traction transformers. Medicine. Advances in HTS promise more compact and less costly Magnetic Resonance Imaging (MRI) systems with superior imaging capabilities. In addition, Magneto-Encephalography (MEG), Magnetic Source Imaging (MSI) and MagnetoCardiology (MCG) enable non-invasive diagnosis of brain and heart functionality. Industry. Large motors rated at 1000 HP and above consume 25% of all electricity generated in the United States. They offer a prime target for the use of HTS in substantially reducing electrical losses. Powerful magnets for water remediation, materials purification, and industrial processing are also in the demonstration stages. Communications. Over the past decade, HTS filters have come into widespread use in cellular communications systems. They enhance signal-to-noise ratios, enabling reliable service with fewer, more widely-spaced cell towers. As the world moves from analog to all digital communications, LTS chips offer dramatic performance improvements in many commercial and military applications. Scientific Research. Using superconducting materials, today’s leading-edge scientific research facilities are pushing the frontiers of human knowledge - and pursuing breakthroughs that could lead to new techniques ranging from the clean, abundant energy from nuclear fusion to computing at speeds much faster than the theoretical limit of silicon technology. Since 10% to 15% of generated electricity is dissipated in resistive losses in transmission lines, the prospect of zero loss superconducting transmission lines is appealing. In prototype superconducting transmission lines at Brookhaven National Laboratory, 1000 MW of power can be transported within an enclosure of diameter 40 cm. This amounts to transporting the entire output of a large power plant on one enclosed transmission line. This could be a fairly low voltage DC transmission compared to large transformer banks and multiple high voltage AC transmission lines on towers in the conventional systems. The superconductor used in these prototype applications is usually niobium-titanium, and liquid helium cooling is required. Current experiments with power applications of high-temperature superconductors focus on uses of BSCCO in tape forms and YBCOin thin film forms. Current densities above 10,000 amperes per square centimeter are considered necessary for practical power applications, and this threshold has been exceeded in several configurations.

Micro Electro Mechanical Systems (MEMS)

Microelectromechanical systems (MEMS) (also written as micro-electro-mechanical, MicroElectroMechanical or microelectronic and microelectromechanical systems and the related micro mechatronics) is the technology of very small devices; it merges at the nano-scale into nanoelectromechanical systems (NEMS) and nanotechnology. MEMS are also referred to as micro machines (in Japan), or micro systems technology – MST (in Europe). MEMS are separate and distinct from the hypothetical vision of molecular nanotechnology or molecular electronics. MEMS are made up of components between 1 to 100 micrometres in size (i.e. 0.001 to 0.1 mm), and MEMS devices generally range in size from 20 micrometres (20 millionths of a metre) to a millimetre (i.e. 0.02 to 1.0 mm). They usually consist of a central unit that processes data (the microprocessor) and several components that interact with the surroundings such as microsensors.[1] At these size scales, the standard constructs of classical physics are not always useful. Because of the large surface area to volume ratio of MEMS, surface effects such aselectrostatics and wetting dominate over volume effects such as inertia or thermal mass Micro-Electro-Mechanical Systems, or MEMS, is a technology that in its most general form can be defined as miniaturized mechanical and electro-mechanical elements (i.e., devices and structures) that are made using the techniques of microfabrication. The critical physical dimensions of MEMS devices can vary from well below one micron on the lower end of the dimensional spectrum, all the way to several millimeters. Likewise, the types of MEMS devices can vary from relatively simple structures having no moving elements, to extremely complex electromechanical systems with multiple moving elements under the control of integrated microelectronics. The one main criterion of MEMS is that there are at least some elements having some sort of mechanical functionality whether or not these elements can move. The term used to define MEMS varies in different parts of the world. In the United States they are predominantly called MEMS, while in some other parts of the world they are called “Microsystems Technology” or “micromachined devices”. While the functional elements of MEMS are miniaturized structures, sensors, actuators, and microelectronics, the most notable (and perhaps most interesting) elements are the microsensors and microactuators. Microsensors and microactuators are appropriately categorized as “transducers”, which are defined as devices that convert energy from one form to another. In the case of microsensors, the device typically converts a measured mechanical signal into an electrical signal. Over the past several decades MEMS researchers and developers have demonstrated an extremely large number of microsensors for almost every possible sensing modality including temperature, pressure, inertial forces, chemical species, magnetic fields, radiation, etc. Remarkably, many of these micromachined sensors have demonstrated performances exceeding those of their macroscale counterparts. That is, the micromachined version of, for example, a pressure transducer, usually outperforms a pressure sensor made using the most precise macroscale level machining techniques. Not only is the performance of MEMS devices exceptional, but their method of production leverages the same batch fabrication techniques used in the integrated circuit industry – which can translate into low per-device production costs, as well as many other benefits. Consequently, it is possible to not only achieve stellar device performance, but to do so at a relatively low cost level. Not surprisingly, silicon based discrete microsensors were quickly commercially exploited and the markets for these devices continue to grow at a rapid rate. More recently, the MEMS research and development community has demonstrated a number of microactuators including: microvalves for control of gas and liquid flows; optical switches and mirrors to redirect or modulate light beams; independently controlled micromirror arrays for displays, microresonators for a number of different applications, micropumps to develop positive fluid pressures, microflaps to modulate airstreams on airfoils, as well as many others. Surprisingly, even though these microactuators are extremely small, they frequently can cause effects at the macroscale level; that is, these tiny actuators can perform mechanical feats far larger than their size would imply. For example, researchers have placed small microactuators on the leading edge of airfoils of an aircraft and have been able to steer the aircraft using only these microminiaturized devices. The real potential of MEMS starts to become fulfilled when these miniaturized sensors, actuators, and structures can all be merged onto a common silicon substrate along with integrated circuits (i.e., microelectronics). While the electronics are fabricated using integrated circuit (IC) process sequences (e.g., CMOS, Bipolar, or BICMOS processes), the micromechanical components are fabricated using compatible "micromachining" processes that selectively etch away parts of the silicon wafer or add new structural layers to form the mechanical and electromechanical devices. It is even more interesting if MEMS can be merged not only with microelectronics, but with other technologies such as photonics, nanotechnology, etc. This is sometimes called “heterogeneous integration.” Clearly, these technologies are filled with numerous commercial market opportunities. While more complex levels of integration are the future trend of MEMS technology, the present state-of-the-art is more modest and usually involves a single discrete microsensor, a single discrete microactuator, a single microsensor integrated with electronics, a multiplicity of essentially identical microsensors integrated with electronics, a single microactuator integrated with electronics, or a multiplicity of essentially identical microactuators integrated with electronics. Nevertheless, as MEMS fabrication methods advance, the promise is an enormous design freedom wherein any type of microsensor and any type of microactuator can be merged with microelectronics as well as photonics, nanotechnology, etc., onto a single substrate. This vision of MEMS whereby microsensors, microactuators and microelectronics and other technologies, can be integrated onto a single microchip is expected to be one of the most important technological breakthroughs of the future. This will enable the development of smart products by augmenting the computational ability of microelectronics with the perception and control capabilities of microsensors and microactuators. Microelectronic integrated circuits can be thought of as the "brains" of a system and MEMS augments this decision-making capability with "eyes" and "arms", to allow microsystems to sense and control the environment. Sensors gather information from the environment through measuring mechanical, thermal, biological, chemical, optical, and magnetic phenomena. The electronics then process the information derived from the sensors and through some decision making capability direct the actuators to respond by moving, positioning, regulating, pumping, and filtering, thereby controlling the environment for some desired outcome or purpose. Furthermore, because MEMS devices are manufactured using batch fabrication techniques, similar to ICs, unprecedented levels of functionality, reliability, and sophistication can be placed on a small silicon chip at a relatively low cost. MEMS technology is extremely diverse and fertile, both in its expected application areas, as well as in how the devices are designed and manufactured. Already, MEMS is revolutionizing many product categories by enabling complete systems-on-a-chip to be realized. There are numerous possible applications for MEMS and Nanotechnology. As a breakthrough technology, allowing unparalleled synergy between previously unrelated fields such as biology and microelectronics, many new MEMS and Nanotechnology applications will emerge, expanding beyond that which is currently identified or known. Here are a few applications of current interest: Biotechnology MEMS and Nanotechnology is enabling new discoveries in science and engineering such as the Polymerase Chain Reaction (PCR) microsystems for DNA amplification and identification, enzyme linked immunosorbent assay (ELISA), capillary electrophoresis, electroporation, micromachined Scanning Tunneling Microscopes (STMs), biochips for detection of hazardous chemical and biological agents, and microsystems for high-throughput drug screening and selection. Medicine There are a wide variety of applications for MEMS in medicine. The first and by far the most successful application of MEMS in medicine (at least in terms of number of devices and market size) are MEMS pressure sensors, which have been in use for several decades. The market for these pressure sensors is extremely diverse and highly fragmented, with a few high-volume markets and many lower volume ones. Some of the applications of MEMS pressure sensors in medicine include: The largest market for MEMS pressure sensors in the medical sector is the disposable sensor used to monitor blood pressure in IV lines of patients in intensive care. These devices were first introduced in the early 1980’s. They replaced other technologies that cost over $500 and which had a substantial recurring cost since they had to be sterilized and recalibrated after each use. MEMS disposable pressure sensors are delivered pre-calibrated in a sterilized package from the factory at a cost of around $10. MEMS pressure sensors are used to measure intrauterine pressure during birth. The device is housed in a catheter that is placed between the baby's head and the uterine wall. During delivery, the baby's blood pressure is monitored for problems during the mother's contractions. MEMS pressure sensors are used in hospitals and ambulances as monitors of a patient’s vital signs, specifically the patient’s blood pressure and respiration. The MEMS pressure sensors in respiratory monitoring are used in ventilators to monitor the patient’s breathing. MEMS pressure sensors are used for eye surgery to measure and control the vacuum level used to remove fluid from the eye, which is cleaned of debris and replaced back into the eye during surgery Special hospital beds for burn victims that employ inflatable mattresses use MEMS pressure sensors to regulate the pressure inside a series of individual inflatable chambers in the mattress. Sections of the mattress can be inflated as needed to reduce pain as well as improve patient healing. Physician’s office and hospital blood analyzers employ MEMS pressure sensors as barometric pressure correction for the analysis of concentrations of O2, CO2, calcium, potassium, and glucose in a patient's blood. MEMS pressure sensors are used in inhalers to monitor the patient’s breathing cycle and release the medication at the proper time in the breathing cycle for optimal effect. MEMS pressure sensors are used in kidney dialysis to monitor the inlet and outlet pressures of blood and the dialysis solution and to regulate the flow rates during the procedure. MEMS pressure sensors are used in drug infusion pumps of many types to monitor the flow rate and detect for obstructions and blockages that indicate that the drug is not being properly delivered to the patient. The contribution to patient care for all of these applications has been enormous. More recently, MEMS pressure sensors have been developed and are being marketed that have wireless interrogation capability. These sensors can be implanted into a human body and the pressure can be measured using a remotely scanned wand. Another application are MEMS inertial sensors, specifically accelerometers and rate sensors which are being used as activity sensors. Perhaps the foremost application of inertial sensors in medicine is in cardiac pacemakers wherein they are used to help determine the optimum pacing rate for the patient based on their activity level. MEMS devices are also starting to be employed in drug delivery devices, for both ambulatory and implantable applications. MEMS electrodes are also being used in neuro-signal detection and neuro-stimulation applications. A variety of biological and chemical MEMS sensors for invasive and non-invasive uses are beginning to be marketed. Lab-on-a-chip and miniaturized biochemical analytical instruments are being marketed as well. Communications High frequency circuits are benefiting considerably from the advent of RF-MEMS technology. Electrical components such as inductors and tunable capacitors can be improved significantly compared to their integrated counterparts if they are made using MEMS and Nanotechnology. With the integration of such components, the performance of communication circuits will improve, while the total circuit area, power consumption and cost will be reduced. In addition, the mechanical switch, as developed by several research groups, is a key component with huge potential in various RF and microwave circuits. The demonstrated samples of mechanical switches have quality factors much higher than anything previously available. Another successful application of RF-MEMS is in resonators as mechanical filters for communication circuits. Inertial Sensing MEMS inertial sensors, specifically accelerometers and gyroscopes, are quickly gaining market acceptance. For example, MEMS accelerometers have displaced conventional accelerometers for crash air-bag deployment systems in automobiles. The previous technology approach used several bulky accelerometers made of discrete components mounted in the front of the car with separate electronics near the air-bag and cost more than $50 per device. MEMS technology has made it possible to integrate the accelerometer and electronics onto a single silicon chip at a cost of only a few dollars. These MEMS accelerometers are much smaller, more functional, lighter, more reliable,

Biogas based Electricity generation plant

Even today in 2013, over 400 million people in India have no access to electricity. Because of the remoteness of much of India’s un-electrified population, renewable energy can offer an economically viable means of undoing this undone. And what better than a biomass power plant. Today, about 32% of the total primary energy use in the country is still derived from biomass and more than 70% of the country’s population depends upon it for its energy needs in some way or the other. Biomass power generation in India is an industry that attracts investments of over Rs.600 crores every year, generating more than 5000 million units of electricity and yearly employment of more than 10 million man-days in the rural areas. We can divide the biomass power plant market in India into 3 categories. Biogas based power projects Present. The current availability of biomass in India is estimated to be approximately640 million metric tones per annum. This converted to cubic meters of biogas comes to 12800 million cubic meters per annum (@ 20 cubic meters of biogas per metric ton of biomass). • This should lead to both electricity and heat generation of 25600 GWh and 51200 GWh per annum respectively (@ 2 KWh of electricity and 4 KWh of heat energy per cubic meter of biogas). • The Government of India has estimated this availability of biomass to a corresponding potential of about 18000 MW generation capacity. • If the above two statements are combined, it comes to around 4 hrs of electricity generation for 365 days a year. Some case studies displayed at MNRE website talk about 6-7 hours of electricity daily in villages using a 10 KW plant. • A total of around 130 biogas power projects have been installed in the country as on date for feeding power to the grid aggregating to 1176.10 MW of generation capacity. Biogas technology, the generation of a combustible gas from anaerobic biomass digestion, is a well-known technology. There are already millions of biogas plants in operation throughout the world. Whereas using the gas for direct combustion in household stoves or gas lamps is common, producing electricity from biogas is still relatively rare in most developing countries. In Germany and other industrialised countries, power generation is the main purpose of biogas plants; conversion of biogas to electricity has become a standard technology. This document will discuss the potentials, obstacles and necessary framework conditions for the utilisation of biogas for small and medium scale electricity generation in developing countries. This paper will not address the biogas production process in general but focus uniquely on electricity generation. The findings presented here are based mainly on available experience from GTZ-related pilot biogas power plants in different countries. They focus on more or less well-documented existing country cases even though little extensive documentation of practical long term operat-ing experience is available. Besides the cases described here, we know of further examples from other GTZ projects (e.g. Bolivia, Tunisia and the Ivory Coast). However, there is not yet sufficient information concerning these to merit inclusion in this assessment. Biogas is gas resulting from an anaerobic digestion process. A biogas plant can convert animal manure, green plants, waste from agro industry and slaughterhouses into combustible gas. Biogas can be used in similar ways to natural gas in gas stoves, lamps or as fuel for engines. It consists of 50-75% methane, 25-45% carbon dioxide, 2-8% water vapour and traces of O2 N2, NH3 H2 H2S. Compare this with natural gas, which contains 80 to 90% methane. The energy content of the gas depends mainly on its methane content. High methane content is therefore desirable. A certain carbon dioxide and water vapour content is unavoidable, but sulphur content must be minimised - particularly for use in engines. The average calorific value of biogas is about 21-23.5 MJ/m³, so that 1 m³ of biogas corre-sponds to 0.5-0.6 l diesel fuel or about 6 kWh (FNR, 2009). The biogas yield of a plant depends not only on the type of feedstock, but also on the plant design, fermentation temperature and retention time. Maize silage for example - a common feedstock in Germany - yields about 8 times more biogas per tonne than cow manure. In most cases, biogas is used as fuel for combustion engines, which convert it to mechanical energy, powering an electric generator to produce electricity. Appropriate electric generators are available in virtually all countries and in all sizes. The technology is well known and maintenance is simple. In most cases, even universally available 3-phase electric motors can be converted into generators. Technologically far more challenging is the first stage of the generator set: the combustion engine using the biogas as fuel. In theory, biogas can be used as fuel in nearly all types of combustion engines, such as gas engines (Otto motor), diesel engines, gas turbines and Stirling motors etc.

Gas turbines are occasionally used as biogas engines, especially in the US. They are very small and can meet strict exhaust emissions requirements. Small biogas turbines with power outputs of 30-75 kW are available on the market, but are rarely used for small-scale applications in developing countries as they are expensive. Furthermore, due to their spinning at very high speeds and the high operating temperatures, the design and manufacturing of gas turbines is challenging and maintenance requires specific skills. External combustion engines such as Stirling motors have the advantage of being tolerant of fuel composition and quality. They are, however, relatively expensive and characterised by low efficiency. Their use is therefore limited to a number of very specific applications. In most commercially run biogas power plants today, internal combustion motors have become the standard technology either as gas or diesel motors.