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Potentials, IEEE

Issue 1 • Date Feb.-March 1996

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Displaying Results 1 - 9 of 9
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  • Adaptive relaying. A new direction in power system protection

    Page(s): 28 - 33
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1136 KB)  

    The authors describe adaptive relaying, a new philosophy in protecting electric power systems. Adaptive relaying utilizes the continuously changing status of the power system as the basis for online adjustment of the power system relay settings. Consequently, it provides the required flexibility for obtaining very high levels of power system reliability. Digital relays with adequate software and communication capability make these devices ideal for implementing adaptive relaying concepts View full abstract»

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  • Programmable logic controllers

    Page(s): 14 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1776 KB)  

    Programmable logic controllers (PLCs) are at the forefront of manufacturing automation. Many factories use programmable logic controllers to cut production costs and/or increase quality. PLCs and their unique language, ladder logic, are the workhorses of factory automation. Higher-level languages, such as sequential function charts and function blocks, ease the programming task for large systems. However, ladder logic remains the dominant language at present View full abstract»

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  • Surge arresters. Protecting equipment from heatstroke

    Page(s): 34 - 36
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB)  

    The authors outline how the main consideration for properly designing a ZnO arrester is the thermal behavior of its components (i.e., their heat transfer properties). They argue that the analysis should be carried out not only in the steady-state of the device, but also in the dynamic and the transient states. Each element must be designed so that the energy handling capability of the assembly is appropriate for the specific duty. Even though manufacturers have achieved outstanding progress in ZnO technology, researchers are working to develop even better devices View full abstract»

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  • Pathfinder. Developing a solar rechargeable aircraft

    Page(s): 18 - 23
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3024 KB)  

    Some assignments, both civilian and military, are better performed by unmanned, long-endurance, solar rechargeable aircraft high in the atmosphere than by satellites in low Earth orbits. These aircraft would have more flexible flight paths and would be far less costly than satellites to design, build, and operate. In collaboration with AeroVironment, Inc., the authors developed a lightweight flying wing, called Pathfinder, that uses present-day technologies in photovoltaics, power electronics, aerodynamics, and guidance and control. Because of its light weight, 30 m wingspan, and intended high peak altitude (2025 km), Pathfinder is span loaded; that is, the weight of all components is distributed as evenly as possible across the five modules that make up its wing. Flight tests have proven the soundness of the concepts and components View full abstract»

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  • Computer simulation

    Page(s): 24 - 27
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1188 KB)  

    Computer simulation is designing a model of an actual or theoretical physical system, executing the model on a digital computer, and analyzing the execution output. Simulation embodies the principle of “learning by doing”-to learn about the system we must first build a model of some sort and then operate the model. Children understand the world around them by simulating (with toys and figurines) most of their interactions with other people, animals and objects. Computer simulation is the electronic equivalent of this type of role playing. It serves to drive synthetic environments and virtual worlds. The paper discusses three primary sub-fields within the overall task of simulation: model design, model execution and model analysis. Graphical output from a physically-based model generated using the program AERO is shown. A manufacturing simulation example is given View full abstract»

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  • A watt-hour meter-the solid state polyphase kind

    Page(s): 9 - 13
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    The old watt-hour revenue meter with its rotating disc is a familiar sight at every electric service entrance, be it residential, industrial, or commercial. However, modern technology has made a solid state version economical for most new polyphase metering installations. Polyphase metering is the norm for all industrial and many commercial consumers. This is because the large power levels and polyphase motors in use require polyphase electric service. New polyphase metering installations now favour solid state meters use because of their economically advantageous versatility and accuracy. In contrast, new single phase meters, the sort seen on all our homes, will probably continue to be electromechanical for some time. This is despite the fact solid state equivalents are available. Solid state single phase meters are being installed in England, however. This article describes how a typical solid state meter, in particular General Electric's Phase3 Electronic Meter, determines energy consumption. Also how it provides many more functions than electromechanical meters View full abstract»

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  • Pure rhenium metal

    Page(s): 37 - 39
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (716 KB)  

    Discusses various properties of the metal rhenium. The properties include: malleability, high-temperature strength, resistance to carburizing and high electrical resistivity across a wide temperature range. This makes rhenium a great candidate for applications where high-temperature strength, wear resistance and erosion resistance is needed View full abstract»

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Aims & Scope

IEEE Potentials is the magazine dedicated to undergraduate and graduate students and young professionals.

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Meet Our Editors

Editor-in-Chief
David Tian
Carnegie Mellon University
david.tian@ieee.org