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Electrical Engineers, Proceedings of the Institution of

Issue 8 • August 1971

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Displaying Results 1 - 16 of 16
  • Electronic-exchange design and flexibility of operation

    Publication Year: 1971, Page(s):955 - 962
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1199 KB)

    Stored-program-controlled exchanges which, because of their flexibility, are generally preferred for new systems, have economic difficulties of application in practice. In a general review of the problems involved, the design of electronic exchanges is analysed, and the flexibility of the various kinds of control is assessed. It is shown that flexibility of call establishment is flexibility not of... View full abstract»

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  • Electronic exchange system. Part 1: Structure

    Publication Year: 1971, Page(s):963 - 971
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1422 KB)

    Continuing from another paper, the equipment for the structure of an electronic telephone exchange is described together with the reasons for the choices made. Analogue circuits are switched by p.a.m./t.d.m. (pulse-amplitude-modulation/time-division-multiplex) switches and p.c.m. (pulse-code-modulation) circuits by t.d.m. switches of the same kind. The use of t.d.m. switches profoundly influences ... View full abstract»

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  • Electronic exchange system. Part 2: Control

    Publication Year: 1971, Page(s):972 - 979
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1351 KB)

    The structure and low-level control equipment of an electronic telephone-exchange system are described in Pt. 1 of the paper. Pt. 2 expands the control to the higher levels of register and unique common control and describes the operation of the whole system. The main problem and objective of the control system is to be economical for all sizes of exchange, for which purpose its cost must be appro... View full abstract»

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  • Characteristic impedance of TEM lines by variational methods

    Publication Year: 1971, Page(s):980 - 982
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (329 KB)

    A variational principle based on duality is developed which is related to the complementary variational principle recently established. As a result, classes of solutions other than those normally obtained can be found for the characteristic impedance of TEM lines. In principle, two separate upper and two separate lower bounds can be determined. A simple example, for which the exact solution is kno... View full abstract»

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  • Effective starting process for Newton-Raphson load flows

    Publication Year: 1971, Page(s):983 - 987
    Cited by:  Papers (22)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (724 KB)

    The results of a noniterative simplified load flow are used as starting values for the Newton-Raphson algorithm. This scheme improves the reliability of the Newton-Raphson method, to the extent that convergence for any physically feasible problem is envisaged, and gives high-accuracy solutions in two or three iterations. The starting process has a number of other valuable uses and may be employed ... View full abstract»

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  • Phasor-trajectory representation of near-resonance transients in quasilinear a.c. circuits

    Publication Year: 1971, Page(s):988 - 992
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (463 KB)

    Some transients in linear a.c. circuits can be advantageously described by a slowly varying phasor. This is true also for a quasilinear RLC network, linearised at the point of near-resonance operation, for a small-perturbation stability analysis. The linearisation of a nonanalytical complex function indicates a tensorial relationship between the variables, but this is not uncommon in other well kn... View full abstract»

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  • Method of digital computation of thyristor switching circuits

    Publication Year: 1971, Page(s):993 - 998
    Cited by:  Papers (26)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (507 KB)

    A general form of computation logic is established for single-phase and 3-phase circuits containing one or more thyristors. Two examples studied in detail are the single-phase RLC circuit with one thyristor and the 3-phase, fullwave, 6-thyristor bridge circuit with an RLC load. Good agreement was found between computed and experimental results. View full abstract»

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  • Development of overhead equipment for British Railways 50Hz a.c. electrification since 1960

    Publication Year: 1971
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1553 KB)

    An account is given of the development of overhead equipment for use on British Railways electrification schemes during the period 1960¿1970. These developments have led to equipment having improved dynamic performance and lower cost. Concurrently, the efficiency of installation has been increased. Economies have followed the disappearance of steam locomotives, allowing the use of less expensive ... View full abstract»

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  • Discussion on 'Commutation phenomena in electrical machines. Part 3: Experiments using the commutator of a production machine'

    Publication Year: 1971
    IEEE is not the copyright holder of this material | PDF file iconPDF (135 KB)
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  • Optimal operation of gas-supply system

    Publication Year: 1971, Page(s):1013 - 1021
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (777 KB)

    This paper illustrates by example how a method of optimisation used in the electrical-engineering field is extended and applied to that of gas engineering. This approach of optimising a general gas system is formlated as a general nonlinear programming problem. All the system parameters are expressed in mathematical representation. The usage of natural gas is also included. An iterative approach b... View full abstract»

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  • Discussion on "Suppression of noise in air-blast circuit breakers"

    Publication Year: 1971, Page(s):1022 - 1024
    IEEE is not the copyright holder of this material | PDF file iconPDF (538 KB)
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  • Effects of finite length in solid-rotor induction machines

    Publication Year: 1971, Page(s):1025 - 1033
    Cited by:  Papers (20)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (900 KB)

    The author presents an analytical solution of Maxwell's equations for the fields in a finite-length, solid-rotor induction motor in which the rotor is not fitted with conducting endrings. It has been assumed as a boundary condition that zero flux enters the ends of the rotor; this is borne out by tests on a typical machine. The solutions for the field distributions are approximate only, but the ap... View full abstract»

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  • Method of measuring sequence voltages on solidly earthed systems

    Publication Year: 1971, Page(s):1033 - 1034
    IEEE is not the copyright holder of this material | PDF file iconPDF (161 KB)
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  • Zubov's method and transient-stability problems of power systems

    Publication Year: 1971, Page(s):1035 - 1040
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (617 KB)

    In this paper, Zubov's method of construction of Lyapunov functions is applied to the transient-stability problem of a synchronous machine swinging against an infinite busbar. In the machine model, the transient saliency and the variable-field flux linkage are taken into account, but changes in prime-mover input have been neglected. Cross-sections of the stability surface for various principal pla... View full abstract»

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  • Online parameter estimation using matrix pseudoinverse

    Publication Year: 1971, Page(s):1041 - 1046
    Cited by:  Papers (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (606 KB)

    A method based on the matrix pseudoinverse is presented for the online identification of discrete-time systems of known order. Recursive algorithms are described which provide minimum-norm estimates of the parameter vector when insufficient data are available, and least-squares estimates with adequate data. These estimates can be updated easily with each pair of additional input-output data, as ma... View full abstract»

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  • Phenomenon of isolated jump resonance and its applications

    Publication Year: 1971, Page(s):1047 - 1050
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (636 KB)

    Under certain conditions of periodic excitation where both the input amplitude as well as the input frequency are varying, nonlinear multimodal systems can be forced exhibit a response in which jumps down occur for both an increase as well as a decrease in input frequency from a median value. This interesting phenomenon is termed `isolated jump resonance¿. Systems of this type exhibit considerabl... View full abstract»

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The Proceedings of the Institution of Electrical Engineers was published by the IET between 1963 and 1979.

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