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Proceedings of the IEE - Part A: Power Engineering

Issue 45 • Date June 1962

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Displaying Results 1 - 11 of 11
  • Electronic analogue computer simulation of multi-machine power-system networks

    Publication Year: 1962 , Page(s): 195 - 202
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (968 KB)  

    The paper describes how a general-purpose electronic analogue computer may be used to simulate multi-machine power-system networks. The transformation of the individual components of the system into a common reference frame is described, together with the derivation of the necessary transformations between rotor reference axes. A four-machine system is used as an example of the method. View full abstract»

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  • Analysis of overall stability of multi-machine power systems

    Publication Year: 1962 , Page(s): 203 - 211
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1400 KB)  

    Conventional methods of assessing the stability of multi-machine power systems neglect many factors, such as flux variation in the synchronous machines and the effect of regulators and governors. With the smaller stability margins characteristic of present-day system design, correct representation of these factors may be of considerable technical and economic importance. Accordingly, a general stability analysis for a multi-machine system is developed, and the solution of the resulting equations by both analogue and digital means is described. The results of a typical stability study on a representative system are presented and the relative effects of various assumptions evaluated. View full abstract»

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  • Discussion on ¿Electronic analogue computer simulation of multi-machine power-system networks¿ and ¿Analysis of overall stability of multi-machine power systems¿

    Publication Year: 1962 , Page(s): 211 - 217
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  • Protection of station equipment against lightning

    Publication Year: 1962 , Page(s): 218 - 224
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (982 KB)  

    Protection of station equipment against lightning over-voltages is usually effected, by voltage-limiting devices such as spark-gaps or surge diverters. When there is appreciable separation between two items of equipment a protective device located near one may not be effective in limiting the voltage at the other to a safe value. The paper is in two parts: in Part 1 the factors determining the most suitable location for the device and its range of protection are investigated, and it is shown that, except for terminal stations involving only one overhead line, the most effective position as on the equipment nearest the overhead line. It is also shown that the range of protection which determines whether more than one protective device is desirable is very dependent on the steepness of front of the over-voltage. The steepness is dependent on the attenuation due to corona during the passage of the over-voltage along the overhead line; this question is examined in Part 2. View full abstract»

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  • Continuous Measurement of Voltage Distribution on a Polluted Insulator String

    Publication Year: 1962 , Page(s): 225 - 228
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (673 KB)  

    A method is described of measuring the voltage simultaneously at several points along a high-voltage insulator string under artificial conditions of severe salt pollution. Electrostatic probes placed opposite the points to be measured give signals from which a simple computer derives the original voltages. Disturbance of the voltage distribution is a minimum and no actual contact is made with the insulator. A response at frequencies up to more than 500c/s and an accuracy of ±5% are obtained. View full abstract»

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  • The Design of Air-Cored Toroids or Linear Couplers

    Publication Year: 1962 , Page(s): 229 - 234
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (719 KB)  

    Linear couplers have been used for busbar protection, but, so far as the authors are aware, detailed consideration of their design and full potentialities has not yet been published. A method of design to secure optimum performance of voltage-summation circuits is considered in detail. Expressions are derived for the internal apparent power of a toroid of any given overall size, together with a rapid trial-and-error method of deducing the appropriate former or air-core size for maximum power output. It is shown that maximum apparent power output depends on former size and, to second order only, on winding space factor. It is determined also by the permeability of air and the conductivity of the winding which are, in general, fixed. Formulae are derived for output voltage per 1 kA in the primary circuit for any given conductor size. They are also obtained for the secondary impedance for specifying a matching relay-coil impedance, or vice versa for designing to a given relay impedance. Appendices give a sample design, test results on stability and operating current of a restricted earth-fault scheme, and a comparison of calculated and measured characteristics. View full abstract»

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  • The wear of graphite sliding on a steel surface and the influence of an electric current on the rate of wear

    Publication Year: 1962 , Page(s): 235 - 242
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1110 KB)  

    A detailed study of the rate of wear of one grade of natural graphite, in the form of two brushes sliding on steel rings, has been made under various conditions of load, apparent contact area, and velocity of sliding Equilibrium conditions are established fairly rapidly at the graphite-metal interface, and the rate of wear is then proportional to the load and independent of the apparent area of contact within the experimental range considered. The passage of a direct electric current increases the rate of wear of graphite brushes, the effect on the positive brush being the more marked. This asymmetrical rate of wear increases with current, is more pronounced at the higher velocities of sliding, and does not depend, in a simple manner, on the load. As the load is increased, the rate of wear for both the positive and the negative brushes decreases initially, though at the higher loads the positive rate of wear increases rapidly. There is evidence that this is due to a changed mechanism of wear. Experimental results on a second grade of brush have shown similar asymmetrical wear at low sliding velocities, which is removed by increased loads, and is also absent at a higher sliding velocity. The experimental results are discussed in terms of an asperity model of the mechanism of wear, analogous to that generally used for friction and metallic wear, with the addition of a rubbed graphitic layer between the steel asperities. It is concluded that asymmetric wear is due to an increased removal of graphite from the positive track, thereby producing increased wear of the brush by the metal asperities. Measurements with a Talysurf profilometer, and experiments with multiple brushes running on a single track, support this view. View full abstract»

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  • Recent developments in 50 c/s bridge networks with inductively coupled ratio arms for capacitance and loss-tangent measurements

    Publication Year: 1962 , Page(s): 243 - 247
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (677 KB)  

    It is shown that considerable advantage may be obtained from the use of bridge networks, for dielectric measurements, which are based on ampere-turn ratio arms. Portable bridges for use at voltages up to 30kV are described, together with a general-purpose 50c/s bridge. View full abstract»

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  • An investigation of excitation-arc phenomena in mercury-pool valves

    Publication Year: 1962 , Page(s): 248 - 256
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1422 KB)  

    The behaviour of the excitation are of two different designs of industrial-type mercury pool valves with anchored cathode spot was systematically investigated, and it was found that: (a) Mean-value measurements of are voltage and current give a falling characteristic in the low-current range because the are fluctuates between two different modes of operation, the mode at a lower current having a higher are voltage than the mode at a higher current. (b) Spontaneous extinction of the excitation are at a current below a critical value in the absence of any main-anode current is caused by a randomly occurring simultaneous failure of the regeneration mechanism for all emission centres which together form the cathode spot. (c) Any extinction of the excitation are as a consequence of a main-anode current pulse is a random phenomenon which always occurs at the end of the main-anode current pulse and which arises when the excitation current is below a critical value, the magnitude of which is dependent on various parameters of valve design and operation. View full abstract»

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  • Discussion on "Magnetostriction in grain-oriented silicon-iron"

    Publication Year: 1962 , Page(s): 257 - 258
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  • Monographs published individually

    Publication Year: 1962
    Save to Project icon | PDF file iconPDF (142 KB)  
    Freely Available from IEEE