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Power Apparatus and Systems, IEEE Transactions on

Issue 4  Part 1 • Date July 1975

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Displaying Results 1 - 25 of 42
  • [Front cover and table of contents]

    Publication Year: 1975 , Page(s): c1
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    Freely Available from IEEE
  • Test results of the world's largest four-pole generators with water-cooled stator and rotor windings

    Publication Year: 1975 , Page(s): 1103 - 1110
    Cited by:  Papers (3)
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    Two turbogenerators, the largest ever produced with direct water-cooling of both rotor and stator windings, were completed and tested early in 1974. Their losses and efficiency from test, together with temperatures in critical areas and cooling circuit behavior are described. Vibration of coil ends was measured at rated voltage and during sudden short circuit using a newly perfected photo cell technique. Based on the test results, it is estimated that generators can now be built in ratings up to 2400 MVA at 1800 rpm using presently available rotor forgings with water-cooled windings. View full abstract»

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  • Weather load model for electric demand and energy forecasting

    Publication Year: 1975 , Page(s): 1111 - 1116
    Cited by:  Papers (33)
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    A method of forecasting the heat sensitive portion of electrical demand and energy utilizing a summer weather load model and taking into account probability variation of weather factors is discussed in this paper. The heat sensitive portion of the load is separated from base load and historical data is used to determine the effect of weather on the system load. This method is based on regression analysis of historical load and weather information and the establishment of system load characteristics based on historical or survey information. The method has been determined primarily for forecasting demands and energy for the intermediate range of from 3 to 10 years. However, it is applicable for monthly and annual peak forecasting, but probably not applicable for short terms such as hour to hour or day to day forecast. It may also be helpful in long term forecasting with appropriate forecast of future quantities of heat sensitive load on the system. Separate weather load models are used for determining the heat sensitive portion of electric energy and demand independently. These correlation studies were made when the author was located in Birmingham, Alabama and all of the studies reported here are on systems in that general area. The author hopes to continue these weather-load correlation studies in the northeast area in the near future. View full abstract»

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  • Investigation of the corona performance of conductor bundles for 800-kV transmission

    Publication Year: 1975 , Page(s): 1117 - 1130
    Cited by:  Papers (6)
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    An investigation of the corona performance of several different conductor bundles for 765/800-kV transmission lines was carried out under a program jointly sponsored by Consumers Power Company and The Detroit Edison Company. The results of tests, carried out on single-phase bundles of 3, 4, 5, and 6 conductors, are presented in the form of generation quantities of audible noise, radio interference, and corona loss. The influence of bundle asymmetry and conductor surface condition on generation quantities was investigated. A comparison of the expected performance of 3- phase transmission lines using several of the tested bundles is given. View full abstract»

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  • Breakdown phenomena of long gaps under switching impulse conditions influence of distance and voltage level

    Publication Year: 1975 , Page(s): 1131 - 1140
    Cited by:  Papers (9)
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    The influence of the different phases of the discharge on the statistics of the breakdown processes has been investigated in a wide range of gap lengths (from 2 to 10 m) and applied voltage levels. The effect of the field distribution, along the gap and of the overvoltage ratio upon the development of each discharge phase, has been studied and the transition between subsequent phases has been analysed. The experimental results have been compared with theoretical predictions; the satisfactory agreement, which has been obtained indicates that the theoretical simulation of the discharge phenomena is relatively advanced and starts to be useful from a engineering point of view. View full abstract»

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  • Static exciter control to improve transient stability

    Publication Year: 1975 , Page(s): 1141 - 1146
    Cited by:  Papers (18)
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    In this paper a stability problem on a future power system is identified. The effect of various types of excitation controls is studied. By modification and trial, changes to the exciter which substantially improve the transient stability are developed. The improvements on this future system are demonstrated. View full abstract»

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  • Decoupling the transient dynamics of adjacent alternators

    Publication Year: 1975 , Page(s): 1147 - 1156
    Cited by:  Papers (3)
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    The transient response of adjacent alternators is examined by means of multivariable control theory. A non-interactive controller is developed based on a linear system model which provides substantial decoupling together with improved transient stability. Examples of the use of the controller are given for both input power and excitation control applied to a simple representation of a three machine system. View full abstract»

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  • Frequency domain analysis applied to digital transmission line protection

    Publication Year: 1975 , Page(s): 1157 - 1166
    Cited by:  Papers (14)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1008 KB)  

    The power system protection function dictates the character of the voltage and current signal processing required in the replacement of switching station instrumentation by digital computers. A complete signal processing technique is designed on the basis of a frequency domain analysis of the protection requirements, and such factors as analog filtering, data window size and sampling frequency are chosen by their frequency characteristícs. The processing technique is demonstrated by applying it to impedance measurement of staged faults. Sub-cycle fault detection is accomplished using an unsynchronized, nonsimultaneous sampling frequency of 240 Hz with simple RC analog filters. View full abstract»

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  • An efficient computer method for simulating transients on transmission lines with frequency dependent parameters

    Publication Year: 1975 , Page(s): 1167 - 1176
    Cited by:  Papers (10)
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    A new technique for computer simulation of transients on transmission lines with frequency dependent parameters is presented. It is similar to the adaptation of Bergeron's method, which is used in the BPA transients program, but since it uses simpler shaped response functions in the required convolution process, the method inherently requires less storage and computational effort in a time-domain simulation. The main disadvantage of the method is the possible increase in programming effort necessary to handle certain types of boundary conditions. Accuracy of the method is verified by comparison with field tests. A new algorithm is also presented for the computation of transmission line response functions. For the functions evaluated in this paper, the method was found to be extremely accurate and computationally more efficient than the Fast Fourier Transform. View full abstract»

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  • Effect of ventilating holes on radial flux and losses in stator slots of turbogenerators

    Publication Year: 1975 , Page(s): 1177 - 1182
    Cited by:  Papers (3)
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    An accepted practice among some manufacturers of turbogenerators is to provide for the ventilation of stator laminations through axial holes in the teeth in addition to the core. This is especially the case for machines without radial ducts separating packs of laminations. These holes are located in areas of the teeth subject to high degrees of saturation. Under these conditions, flux is diverted into adjacent stator slots. The main component of the diverted flux is radial and is in the area of the strands. Furthermore, this radial flux component is time varying and hence establishes eddy currents in the strands. These eddy currents create additional losses. Therefore, the size and location of such ventilation holes is critical if the added component of radial flux losses is not to produce spots of excessive heating in the winding. This phenomenon is presented through results of a comprehensive magnetic field study on two 4 pole, 659 MVA asymmetrically slotted rotor and 2 pole, 733 MVA standard rotor turbogenerators. From flux density and loss distribution curves, recommendations as to the size and location of these holes, to significantly reduce these losses are made. View full abstract»

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  • Grounding of gas insulated substations

    Publication Year: 1975 , Page(s): 1183 - 1191
    Cited by:  Papers (6)
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    The Grounding of Gas Insulated Substations (GIS) presents several unique problems not encountered in the grounding, of conventional substations. For the purposes of this paper, Gas Insulated Substations are defined as high-voltage, compact, metal-enclosed minisubstations which are compressed gas insulated at maximum rated voltages of 72.5 kV and above. The metal enclosure is grounded and consists of the outer sheath for the substation equipment and the coaxial gas insulated bus. The maximum voltage developed on the grounded outer sheath during fault conditions is calculated using coupling techniques and a transformer equivalent circuit. By setting limits on the maximum outer sheath voltage to station ground, the maximum distance between grounding points can be determined for the safety of personnel in a Gas Insulated Substation. View full abstract»

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  • Experimental results on the implementation of an optimal control for synchronous machines

    Publication Year: 1975 , Page(s): 1192 - 1200
    Cited by:  Papers (15)
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    This paper records the experimental results on the implementation of optimal controllers for synchronous machines based on nonlinear and linear system models. First, a method is developed for synthesizing a closed - loop optimal control for the case of a non-linear machine model. The validity of this optimal control is then established by implementing it on a micro - machine connected to a short transmission line and driven by an armature-controlled d.c. motor. Comparison of test results with those of digital simulation demonstrate the practical usefulness of optimal controllers in improving synchronous machine transient response. Experimental results are presented to show that while optimal controllers based on a linear model perform quite well for small disturbances, those based on a nonlinear model yield a better response for large disturbances. Several other factors related to optimal control design, such as the improvement of transient response, effect of various parameters on optimal performance, coice of order for system model etc. are also discussed. View full abstract»

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  • Identification of excitation system parameters

    Publication Year: 1975 , Page(s): 1201 - 1207
    Cited by:  Papers (5)
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    A comprehensive set of tests were conducted to determine the parameters of the excitation system of a turbo-generator. Various test methods were investigated during preliminary tests on the isolated regulator. As a result of these, small-signal frequency response measurements were carried out on the excitation system with the generator on-line. In addition, the response of various generator and excitation variables were recorded following faults on the power system. From the frequency response tests and the fault recordings, small-, medium-, and large-signal models of the excitation system were proposed. View full abstract»

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  • Generator protection with a new static negative sequence relay

    Publication Year: 1975 , Page(s): 1208 - 1213
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (504 KB)  

    This paper describes the development of a new static negative sequence relay for generator protection. This relay has a broader range of settings and greater sensitivity to provide protection for modern large generators as well as units in unattended stations, such as remote-controlled hydro and gas turbine peaking plants. An example is given of its application, in light of newly proposed ANSI standards. View full abstract»

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  • A matrix method for optimal var siting

    Publication Year: 1975 , Page(s): 1214 - 1222
    Cited by:  Papers (5)
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    The load flow problem is formulated in linearized form in which complex notation is retained. Various criterion functions are proposed for optimal reactive power (VAr) siting, and the linear load flow results are used in a gradient scheme to affect the optimization. Matrix notation is used, and computational advantages are noted over existing VAr siting techniques; among these advantages are accuracy, computation speed, and convenient sub-optimal solution when some system busses are unavailable for VAr placement. View full abstract»

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  • Rapid methods for transmission tower structural analysis and design

    Publication Year: 1975 , Page(s): 1223 - 1231
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    The electric transmission system power flow equations bear a striking similarity to force-displacement characteristics of pin-joint structures such as electrical transmission towers. In this paper, the structural analog to the electric power system equations is made in vector-matrix terms and contemporary techniques are applied for rapid analysis and design of transmission towers. In particular, the linearized power flow technique and the Kron reduction technique for impedance matrix modification are applied in order to radically increase the speed of analysis of transmission tower structures. The increase in speed and the nature of the problem formulation allows structural design techniques in reasonable digital processing times. View full abstract»

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  • Transfer of the kilowatthour

    Publication Year: 1975 , Page(s): 1232 - 1240
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    An Edison Electric Institute (EEI) - National Bureau of Standards (NBS) research project was conducted in order to determine how accurately the unit of energy (kilowatthour) is maintained in the electric utility laboratories, and to investigate methods of improving the transfer of the unit of energy. This paper discusses the establishment of a testing facility and the evaluation of energy transfer standards. Recommendations are given for the performing of interlaboratory tests (round-robins) and the use of special containers for shipping standards by commercial airlines. View full abstract»

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  • Bibliography of publications pertaining to lightning protection

    Publication Year: 1975 , Page(s): 1241 - 1247
    Cited by:  Papers (1)
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    This bibliography lists the various publications dealing in whole or in part with the mechanism of lightning and the schemes which have been used to provide protection against lightning strokes for substations, lines, and structures. Both historical and present-day theory and practice are covered. View full abstract»

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  • Guide for design and specification for concrete pole structures

    Publication Year: 1975 , Page(s): 1248 - 1257
    Cited by:  Papers (3)
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    This is a report of the Task Group on Line Loading and Strength for Transmission Line Structures of the Towers, Poles and Conductors Subcommittee, Subgroup 3, Structure Development, of the Transmission and Distribution Committee. The purpose of this report is to familiarize the industry with concrete pole structures and to provide a guide for design and manufacture of the structures. An appendix provides an example method for calculating ultimate moment capacity of a fully prestressed concrete section. View full abstract»

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  • Microvoids in crosslinked polyethylene insulated cables

    Publication Year: 1975 , Page(s): 1258 - 1263
    Cited by:  Papers (21)  |  Patents (2)
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    This paper explains the main. cause of the formation of microvoids (1µm-several 10sµm) in the insulation of crosslinked polyethylene, and the effect of those on the electrial characteristics of cable. Crosslinked polyethylene cable is produced through the process of extruding, moulding, heating, crosslinking and cooling. Steam is usually used as the heating medium. The first cause of the formation of microvoids is the steam intruding into the insulation at the time of vulcanization, and the insulation of steam cured crosslinked polyethylene cable generally contains microvoids several µm in size and around 106per mm3in number. If a heating medium other than steam should be used, the number of voids can be reduced by around 104per mm3, but it is quite difficult to bring it down to zero. While cable breakdown voltage may scarcely be affected by the size and number of the microvoids at present concerning us, the dimension of bow tie tree induced by the microvoids is approximately proportional to the diameter of voids, and so efforts must be made to reduce the diameter of voids. View full abstract»

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  • A design concept for large superconducting alternators

    Publication Year: 1975 , Page(s): 1264 - 1269
    Cited by:  Papers (8)
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    The necessity for system damping and fault survival have imposed requirements on superconducting alternators not considered in earlier studies. These requirements impinge mostly on the rotor shielding system, and seem to indicate a two-component rotor damper/shield. Projections of machine size and performance indicate that even with the new requirements, superconducting machines retain their projected advantage over conventional machines. View full abstract»

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  • Frequency deviation transducer for power system applications

    Publication Year: 1975 , Page(s): 1270 - 1274
    Cited by:  Papers (11)
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    A frequency deviation transducer using solid-state circuitry has been developed. The device is based on digital - analogue technique and is suitable for continuous record of power system frequencies and governor application with a high order of accuracy. No initial adjustments are required and no reset problems are faced. Depending on application requirements, the transducer may be used alone for direct measurement or in combination with other control equipment for automatic load frequency control, excitation control, load shedding and in acceleration relay applications etc. View full abstract»

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  • A study of early valve actuation using detailed prime mover and power system simulation

    Publication Year: 1975 , Page(s): 1275 - 1287
    Cited by:  Papers (7)
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    Results of studies exploring the effects of early valve actuation on the stability of a nuclear station and a fossil-fired station are presented. The studies were performed on multimachine systems using a detailed representation of steam turbines. The sensitivity effects of the valve actuation times were investigated and the importance of such an investigation is demonstrated. View full abstract»

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  • Improvement in critical clearing time calculation by a new equation of motion in the on-fault condition

    Publication Year: 1975 , Page(s): 1288 - 1293
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    In the stability analysis of power systems, the influence of the abrupt output change on the electromagnetic torque Temin the on-fault condition is conventionally neglected. A straight and rigorous method to derive the corresponding approximated expression of Tem, strictly based on the generally accepted Park-equations and known parameterratios, is presented. The resulting improvement in the accuracy of the calculations of the critical clearing time is shown to be highly significant. View full abstract»

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  • Experience with part-winding resonance in EHV auto-transformers: Diagnosis and corrective measures

    Publication Year: 1975 , Page(s): 1294 - 1300
    Cited by:  Papers (20)
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    Four failures of large EHV auto-transformers on the AEP system are described. The failures were initiated by flashovers in the no-load tap changer during system faults. Investigations and tests attribute the flashovers to part-winding resonance. Test data is presented for various terminal conditions and wave shapes corresponding to system transient conditions. The relationship of these tests to ANSI standard dielectric tests is discussed. Corrective measures for existing transformers include arresters tied to an internal crossover connection and capacitor banks connected to the delta tertiary windings. View full abstract»

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Aims & Scope

This Transactions ceased production in 1985. The current retitled publication is IEEE Transactions on Energy Conversion and IEEE Transactions on Power Delivery, and IEEE Transactions on Power Systems.

Full Aims & Scope