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    Electrical engineering calculations [History]

    Powell, L. ; Hesla, E.
    Industry Applications Magazine, IEEE

    Volume: 15 , Issue: 6
    DOI: 10.1109/MIAS.2009.934445
    Publication Year: 2009 , Page(s): 8 - 11

    IEEE Journals & Magazines

    Engineers can calculate short circuit currents with their laptop (and even palmtop) computers. Not only do these tools calculate currents far more quickly and with greater precision and accuracy than the methods used in the past, but they also have the ability to immediately evaluate the application of specific circuit breakers and evaluate the arc-flash energy released at the point of fault. But to truly appreciate these modern tools, we have to appreciate the fascinating history of this most simple of all electrical engineering calculations. This paper discusses the history of short-circuit calculations. View full abstract»

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    Two-dimensional simulation of ac-driven microplasmas confined to 100–300 μm diameter cylindrical microcavities in dielectric barrier devices

    Jeong Hyun Seo ; Eden, J.G.
    Journal of Applied Physics

    Volume: 100 , Issue: 12
    DOI: 10.1063/1.2398024
    Publication Year: 2006 , Page(s): 123302 - 123302-8
    Cited by:  Papers (2)

    AIP Journals & Magazines

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    Parameter study of load combinations in seismic design for UHV transformation devices

    Lu Zhicheng ; Dai Zebing ; Zhu Zhubing
    Power System Technology (POWERCON), 2010 International Conference on

    DOI: 10.1109/POWERCON.2010.5666551
    Publication Year: 2010 , Page(s): 1 - 6

    IEEE Conference Publications

    For UHV electrical devices, owing to their importance, uniqueness, and relatively high safety margin requirements, their seismic performance has become the focus of engineer's attention. Such devices are prone to generate resonance under the effects of earthquake, which will lead to damage to them. Moreover, most of the major devices have exceed the application scope of seismic design criteria, and values of related parameters of seismic design are different based on different criteria. Therefore, it is necessary that study on relevant problems existing in the seismic design of UHV transformation devices is carried out. In this study, the related clauses in Code for seismic design of buildings (GB50011-2001), Code for design of seismic of electrical installations (GB50260-96) and IEEE Recommended Practice for Seismic Design of Substations (IEEE Std 693) were compared and analyzed, and at the same time, the parameters of load combinations in the seismic design (i.e. every subentry coefficient and safety coefficient) were studied. With the device of some UHV project taken as an example of project study, a practical calculation method that could be applied to analysis of earthquake resistance of UHV transformation devices was proposed, and the analysis result could be referred by related professional personnel. View full abstract»

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    Electricity the future power for steering vessels

    Hibbard, H.L.
    American Institute of Electrical Engineers, Proceedings of the

    Volume: 33 , Issue: 5
    DOI: 10.1109/PAIEE.1914.6660856
    Publication Year: 1914 , Page(s): 703 - 732

    IEEE Journals & Magazines

    Electrical development in the marine field has been confined in a large measure to the navy, and the best experience with electric steering gears has been obtained from navy installations. Up to the present time steam has been the universal power for operating steering gears but certain disadvantages are inherent in this system which can be overcome by the electric drive, and additional advantages obtained. The history of electric gears shows that many different schemes have been tried and proved failures owing to faulty designs and imperfectly developed apparatus. At present several different systems are in successful operation. To obtain full benefit of the advantages possible from an electric drive, much depends on the selection of apparatus with characteristics best suited to the work. The problem of electric drive is largely one of control. The calculations for rudder and motor horse powers must be carefully made, with the proper assumptions for the conditions presented. Several installations in the navy have shown excellent results; in the case of the battleship Texas the data obtained show preliminary calculations were quite accurate. Results obtained seem to justify the prediction that electric steering gears will be used quite generally in the future. View full abstract»

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    Calculation of stray load losses

    Rockwood, G.H.
    American Institute of Electrical Engineers, Transactions of the

    Volume: XLVI
    DOI: 10.1109/T-AIEE.1927.5061452
    Publication Year: 1927 , Page(s): 1139 - 1147
    Cited by:  Papers (1)

    IEEE Journals & Magazines

    Early in the history of the development of the alternating current (AC) generator it was recognized that there might be losses present under load conditions in addition to the no-load losses and the armature copper loss due to load current. Because no one had a satisfactory means of measuring this loss it was not included in the early definitions of conventional efficiency. In 1913 papers were presented giving the results of carefully made input - output tests which tended to show that the entire loss on sustained polyphase short circuit should be taken as a measure of the stray load loss for the salient pole alternator. This rule has remained in force and in view of its general acceptance it is to the interest of designers of salient pole alternators to be able to predetermine this loss. It is the purpose of thispaper to present some general methods of attacking the problem. It is not intended that the results should be complete but they are presented simply as a starting point for the attack on this problem. Instead of trying to develop a single formula for the short circuit core loss, it is desirable to separate the total loss into distinct parts and develop. formulas for each of these parts separately. The parts into which it is most conveniently divided are: 1. An eddy current loss in the armature copper. 2. A loss in the stator iron. 3. A pole face loss. 4. An end loss. 5. A loss in the amortisseur winding. These component parts will be discussed in turn. View full abstract»

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    Clinton R. Hanna 1955 Lamme medalist: History of the medal

    Pilliod, J. J.
    Electrical Engineering

    Volume: 75 , Issue: 8
    DOI: 10.1109/EE.1956.6442070
    Publication Year: 1956 , Page(s): 706

    IEEE Journals & Magazines

    Dr. Hanna of the Westinghouse Laboratories, Pittsburgh, Pa., has been awarded the 1955 Lamme Medal “… for his fundamental calculations and developments in the field of electrodynamics and particularly for his achievements in the design of generator voltage regulators, automatic rolling mill controls, and tank gun stabilizers.” View full abstract»

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    Electricity the Future Power for Steering Vessels

    Hibbard, H. L.
    American Institute of Electrical Engineers, Transactions of the

    Volume: XXXIII , Issue: 1
    DOI: 10.1109/T-AIEE.1914.4765149
    Publication Year: 1914 , Page(s): 619 - 657

    IEEE Journals & Magazines

    Electrical development in the marine field has been confined in a large measure to the navy, and the best experience with electric steering gears has been obtained from navy installations. Up to the present time steam has been the universal power for operating steering gears, but certain disadvantages are in-herent in this system which can be overcome by the electric drive, and additional advantages obtained. The history of electric gears shows that many different schemes have been tried and proved failures owing to faulty designs and imperfectly developed apparatus. At present several different systems are in successful operation. To obtain full benefit of the advantages possible from an electric drive, much depends on the selection of apparatus with characteristics best suited to the work. The problem of electric drive is largely one of control. The calculations for rudder and motor horse powers must be carefully made, with the proper assumptions for the conditions presented. Several installations in the navy have shown excellent results; in the case of the battleship Texas the data obtained show preliminary calculations were quite accurate. Results obtained seem to justify the prediction that electric steering gears will be used quite generally in the future. View full abstract»

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    Mutual influencing analysis of seismic response of underground and above ground frame structures

    Liu Qianwen
    Transportation, Mechanical, and Electrical Engineering (TMEE), 2011 International Conference on

    DOI: 10.1109/TMEE.2011.6199194
    Publication Year: 2011 , Page(s): 267 - 270

    IEEE Conference Publications

    With the development of subway construction in China, the scale of exploitation and utilization of underground space is becoming more and more larger. The dynamic characteristics of soil-above ground structure must be changed with the existence of underground structure, and therefore, the seismic ability of above ground structures will be influenced. The calculation models for soil-underground frame structure-above ground structure interaction system are established based on finite element method. The mutual influencing on seismic response of underground structure and above ground structure are calculated and analyzed. The analysis showed that above ground frame structure has little influence on the seismic response of underground structure, while the underground structure has great influence on the seismic of above ground structure. The results in the paper can provide references for the seismic design of underground and above ground structures. View full abstract»

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    Condition monitoring of power transformers using DGA and Fuzzy logic

    Nemeth, B. ; Laboncz, S. ; Kiss, I.
    Electrical Insulation Conference, 2009. EIC 2009. IEEE

    DOI: 10.1109/EIC.2009.5166373
    Publication Year: 2009 , Page(s): 373 - 376
    Cited by:  Papers (4)

    IEEE Conference Publications

    Dissolved gas Analysis (DGA) is a widely used technique to estimate the condition of oil-immersed transformers. The measurement of the level and the change of combustible gases in the insulating oil is a trustworthy diagnostic tool which can be used as indicator of undesirable events occurring inside the transformer, such as hot spots, electrical arcing or partial discharge. The objective of this paper is mainly to analyze available data from DGA, and investigate data that may be useful in quantitative modeling of the transformer's reliability. There are standards available for this purpose the DGA interpretation should also be based on other information about the reliable particular transformer. This paper describes a realistic method for power transformers using readily available data. The method considers practical limitations on obtaining data and possible constraints on the parameters utilize IEC, IEEE, and OGRE criteria. The calculation considers not only typical test results but also other parameters such as physical observations, tap changer and bushing condition, load history, maintenance work orders, age, trends of the transformer failures etc. The calculation includes condition ratings, weighting factors, and assigned scores for specific condition parameters by using fuzzy logic. A neural network using the DGA results is applied to achieve the initial conclusion firstly. Then, several fuzzy equations are established to realize the detailed diagnosis. As many sorts of data and relevant DGA information are selected in different fuzzy equations, which result in the accuracy of the detailed diagnosis being higher. View full abstract»

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    Image resizing using improved seam merging

    Mishiba, K. ; Ikehara, M.
    Acoustics, Speech and Signal Processing (ICASSP), 2012 IEEE International Conference on

    DOI: 10.1109/ICASSP.2012.6288118
    Publication Year: 2012 , Page(s): 1261 - 1264

    IEEE Conference Publications

    In this paper, we propose the improved seam merging method for content-aware image resizing. This method merges a two-pixel-width seam element into one new pixel in image reduction and inserts a new pixel between the two pixels in image enlargement. To preserve important contents and structure, our method uses importance and structure energies. Using the cartoon image of an original image for calculation of structure energy, our method can preserve main structure. In addition, we introduce new energy to suppress distortion generated by excessive reduction or enlargement in the iterative merging or inserting. Experimental results demonstrate that the proposed method can produce satisfactory results in both image reduction and enlargement. View full abstract»

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    Submarine Cable Telegraphy

    Milnor, J.Willard
    American Institute of Electrical Engineers, Transactions of the

    Volume: XLI
    DOI: 10.1109/T-AIEE.1922.5060759
    Publication Year: 1922 , Page(s): 20 - 38
    Cited by:  Papers (6)

    IEEE Journals & Magazines

    The history of the development of the subject is first outlined, and methods of operation of cables are described. The technical side is introduced with a statement of the various conditions whi h limit operation of cables, and a general method of analysis is developed, based upon an extension of ordinary alternating-current theory. The theory is made use of to analyze the action of cable types and of apparatus which at this time can be regarded as standard. The fundamental theory of the method of analysis, with information on the calculation of transients in electrical circuits, is given in the Appendix. View full abstract»

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    Instantaneous wave number based structural damage detection

    Dong Yinfeng ; Li Xupeng ; Jiang Fan
    Electrical and Control Engineering (ICECE), 2011 International Conference on

    DOI: 10.1109/ICECENG.2011.6058465
    Publication Year: 2011 , Page(s): 5299 - 5301

    IEEE Conference Publications

    A method based on instantaneous wave number is proposed for structural damage detection, which is designated to describe the change of structural dynamic properties with time caused by damage. Based on the wave theory, the derivation of wave number is introduced first. Then, the method for modal parameter identification and instantaneous wave number calculation using time-varying vector autoregressive moving average (VARMA) model is depicted. Finally, the instantaneous wave number is used as the index to identify the damage of structures. Analysis results of an actual structure show that the occurrence and developing process of structural damages can be precisely identified using this index, as well, the severity of damage can be indicated exactly by spikes of instantaneous wave number. View full abstract»

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    Mechanical considerations for uprate and rehabilitation of hydro-generators

    Moore, W.G.
    Electric Machines and Drives, 1999. International Conference IEMD '99

    DOI: 10.1109/IEMDC.1999.769254
    Publication Year: 1999 , Page(s): 824 - 826

    IEEE Conference Publications

    Electrical design procedures for the purpose of generator uprating are relatively straightforward calculations, based on the space available in the slot, desired insulation system, desired operating parameters and the magnitude of the uprating. More involved, and sometimes overlooked, are the mechanical design calculations to ensure that these machines are safe to operate at the higher levels. In a recent generator refurbishment and uprate by the author's company, large cracks were found in the spider arm to hub area. This machine would have failed mechanically at the higher rating. Its rotor cracks were extensively evaluated with root cause determination, and subsequently repaired. Before looking at this particular case history, a general overview of the mechanical calculations required for uprating are given View full abstract»

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    Submarine cable telegraphy

    Milnor, J.Willard
    American Institute of Electrical Engineers, Journal of the

    Volume: 41 , Issue: 2
    DOI: 10.1109/JoAIEE.1922.6593983
    Publication Year: 1922 , Page(s): 118 - 136

    IEEE Journals & Magazines

    The history of the development of the subject is first outlined, and methods of operation of cables are described. The technical side is introduced with a statement of the various conditions which limit operation of cables, and a general method of analysis is developed, based upon an extension of ordinary alternating-current theory. The theory is made use of to analyze the action of cable types and of apparatus which at this time can be regarded as standard. The fundamental theory of the method of analysis, with information on the calculation of transients in electrical circuits, is given in the Appendix. View full abstract»

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    Theory and Calculation of the Squirrel Cage Repulsion Motor

    West, H.R.
    American Institute of Electrical Engineers, Transactions of the

    Volume: XLIII
    DOI: 10.1109/T-AIEE.1924.5061060
    Publication Year: 1924 , Page(s): 1048 - 1057
    Cited by:  Papers (1)

    IEEE Journals & Magazines

    A brief history of the development of the squirrel cage repulsion motor and a physical explanation of the principles of its operation have been given in the preceding paper ``A New Type of Single Phase Motor'' by Mr. S. R. Bergman. It is the purpose of the present paper to give the results of an analytical study of the operation of the motor. The derivation of the method of calculation is outlined and some of the more interesting results are given. View full abstract»

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    Calculation of Slot Constants

    Puchstein, A.F.
    American Institute of Electrical Engineers, Transactions of the

    Volume: 66 , Issue: 1
    DOI: 10.1109/T-AIEE.1947.5059577
    Publication Year: 1947 , Page(s): 1315 - 1323
    Cited by:  Papers (6)

    IEEE Journals & Magazines

    First Page of the Article
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    Equipment health rating of power transformers

    Dominelli, N.
    Electrical Insulation, 2004. Conference Record of the 2004 IEEE International Symposium on

    DOI: 10.1109/ELINSL.2004.1380501
    Publication Year: 2004 , Page(s): 163 - 168
    Cited by:  Papers (5)

    IEEE Conference Publications

    Transformers are major components of the power delivery system. In North America, a large proportion of them are approaching their end of design life and in need of replacement or refurbishment A program has been developed to assist engineers to diagnose and assess the health of power transformers. The program uses test and inspection data and equipment information such as nameplate, known design problems, operating history, and age to determine the equipment's health rating. The program calculates condition indexes of transformer components then combines them into an equipment health rating. Although the program automatically calculates such values, it also allows for experts to provide diagnostics and make recommendation on intervention, and to review all the final rating . The results can be used to quickly assess equipment health and provide comparison within a substation or the entire utility for asset management. Examples and case histories are used to show the merits and applications of the program for BC Hydro's system. View full abstract»

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    Computation of transient Eddy currents in EMATs using discrete Picard Method

    Noorian, F. ; Sadr, A.
    Electrical Engineering (ICEE), 2010 18th Iranian Conference on

    DOI: 10.1109/IRANIANCEE.2010.5506979
    Publication Year: 2010 , Page(s): 727 - 731

    IEEE Conference Publications

    This paper presents a new method for solving transient Eddy current problems in EMAT non-destructive testing calculations. Using a linear approximation of differential operators, problem's underlying differential equation is discretized in space, while being kept continuous in time; then Picard Method is exploited to solve the resulting equation numerically. Results are compared to analytical models and previous formulations and good agreement is found. View full abstract»

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    Performance assessment without pyranometers: Predicting energy output based on historical correlation

    Golnas, A. ; Bryan, J. ; Wimbrow, R. ; Hansen, C. ; Voss, S.
    Photovoltaic Specialists Conference (PVSC), 2011 37th IEEE

    DOI: 10.1109/PVSC.2011.6186347
    Publication Year: 2011 , Page(s): 002006 - 002010
    Cited by:  Papers (1)

    IEEE Conference Publications

    Estimating the energy that should be generated by a PV system under the prevailing conditions of irradiance and temperature is very important for system or fleet investors, energy customers, and operators. Traditionally this has been achieved by measuring irradiance and temperature in the proximity of the PV array in order to calculate the expected energy output either by using an appropriate model or by making assumptions about the system's Performance Ratio. However, this method requires the accurate installation, maintenance, and continuous monitoring of sensors thereby increasing the system's capital and maintenance costs. In this work we present an alternative methodology which can calculate the expected output of one or more systems in a regional fleet based on the measured power output from a subset of the total fleet. This can be achieved thanks to high accuracy energy measurements and the ability to correlate historical performance records. View full abstract»

  • Freely Available from IEEE

    1884-1984: A Century of Electrical Progress


    Micro, IEEE

    Volume: 4 , Issue: 1
    DOI: 10.1109/MM.1984.291306
    Publication Year: 1984 , Page(s): 23

    IEEE Journals & Magazines

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    The electrical century. What difference did semiconductors and microelectronics make?

    Morton, D.
    Proceedings of the IEEE

    Volume: 87 , Issue: 6
    DOI: 10.1109/5.763320
    Publication Year: 1999 , Page(s): 1049 - 1052

    IEEE Journals & Magazines

    This year, according to one historian's calculations, the transistor turns 52 years old, the integrated circuit 41 years, and the microprocessor 28. While the exact birth dates for these technologies are hotly contested by various inventors, one fact is clear: microelectronics has an undeniable significance today. The making of electronic components is a major industry worldwide, and the range of products incorporating microelectronics seems to expand every day. The transistor and its successor, the integrated circuit, were radical developments that became part of revolutionary new technologies, but it is also true that each of them emerged within the context of ongoing research and commercialization stretching back at least to the 1930's. Like so many new technologies, microelectronics extended and enhanced trends that were already well established and at the same time opened doorways to entirely new opportunities View full abstract»

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    The realizations of fast wavelet transform algorithms based on DSP

    Guo Jichang ; Liu Yan ; Li Xiangping ; Li Qiang ; Zhang Yaqi
    Electrical and Computer Engineering, 2003. IEEE CCECE 2003. Canadian Conference on

    Volume: 3
    DOI: 10.1109/CCECE.2003.1226309
    Publication Year: 2003 , Page(s): 2005 - 2008 vol.3

    IEEE Conference Publications

    Wavelet transform is an important branch as a new theory in the history of mathematics. It is a signal analyzing and processing method in time-frequency domain, and has an excellent local character in time domain and frequency domain. Wavelet transform has led to many new wavelets applications in various fields such as signal detection, signal processing and image processing, and the hardware realization of wavelet transform algorithms receives more and more recognition. This paper introduces the principle of fast wavelet transform and the realizing method in DSP. The DSP instructions such as parallel multiply-accumulate instruction, circular addressing and repeating operation in TMS320C3X of, which are suitable to realize the wavelet algorithms, are described in detail. A framework of assemble language program for the calculation of scale expanding value is given out and the problem which should be paid attention to in the fast wavelet algorithms using DSP is discussed specially. View full abstract»

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    Micromagnetics, Domains, and Resonance

    Brown, William Fuller
    Journal of Applied Physics

    Volume: 30 , Issue: 4
    DOI: 10.1063/1.2185970
    Publication Year: 1959 , Page(s): S62 - S69
    Cited by:  Papers (4)

    AIP Journals & Magazines

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    Monte Carlo Computer Calculation of Transmission-Line Lightning Performance

    Anderson, J.G.
    Power Apparatus and Systems, Part III. Transactions of the American Institute of Electrical Engineers

    Volume: 80 , Issue: 3
    DOI: 10.1109/AIEEPAS.1961.4501060
    Publication Year: 1961 , Page(s): 414 - 419
    Cited by:  Papers (39)

    IEEE Journals & Magazines

    First Page of the Article
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    Graphical Determination of Magnetic Fields Theoretical Considerations

    Stevenson, A.R. ; Park, R.H.
    American Institute of Electrical Engineers, Transactions of the

    Volume: XLVI
    DOI: 10.1109/T-AIEE.1927.5061344
    Publication Year: 1927 , Page(s): 112 - 135
    Cited by:  Papers (20)

    IEEE Journals & Magazines

    Three papers on the general subject, ``Graphical Determination of Magnetic Fields,'' are being presented simultaneously to cover three phases of the subject: 1. Theoretical Considerations, 2. Comparison of Calculations and Tests, by E. E. Johnson and C. H. Green, 3. Practical Applications to Salient-Pole Synchronous Machine Design, by R. W. Wieseman. In the following paper, which is the first of this series, the authors have reviewed the history of the subject, hare briefly stated the ordinary rules for plotting magnetic flux in air and in current-carrying copper, have developed additional rules for checking the accuracy of field plots, and have given theoretical methods for mathematically calculating the distribution of field in certain cases commonly encountered in practise. The authors have called attention to the great value of the mathmatical work by the German engineer, Rogowski, and the graphical methods by the French engineer, Lehmann. These German and French articles contain the only extensive practical applications of the plotting of magnetic fields in current-carrying regions with which the present authors are familiar. Since it is much more difficult to plot fields in current-carrying regions, and since the majority of readers are less familiar with this phase of the subject, the greater part of the first paper, ``Theoretical Considerations,'' is devoted to a study of such fields. View full abstract»

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