Electrical Engineers, Proceedings of the Institution of

Issue 5 • May 1972

Filter Results

Displaying Results 1 - 25 of 28
  • Carrier wave in n type gallium arsenide under crossed d.c. electric and magnetic fields

    Publication Year: 1972, Page(s):505 - 511
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (777 KB)

    Assuming that current-density/electric-field curves are provided and that the Hall mobility does not change appreciably with the electric field, the small-signal tensor conductivity of n-GaAs in the presence of d.c. electric and magnetic fields is derived. Using this tensor conductivity, carrier-wave equations are solved for a long slab of n-GaAs sandwiched between dielectrics. It is found that wa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pseudorandomly dithered quantisation of speech samples in p.c.m. transmission systems

    Publication Year: 1972, Page(s):512 - 518
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (889 KB)

    The paper reports on an investigation of the application of variable-level quantisation in p.c.m.-type speech-transmission systems. Variable-level (dithered) quantisation systems are compared with normal fixed-level quantisation systems. The systems are compared using intelligibility tests and subjective-appreciation tests, and a statistical analysis of the results is given. The analysis indicates... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of hollow elliptical waveguides by polygon approximation

    Publication Year: 1972, Page(s):519 - 522
    Cited by:  Papers (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (512 KB)

    Numerical results for elliptical waveguides are usually obtained from the appropriate Mathieu and associated Mathieu functions, but these are expensive to compute, because of slow convergence, and difficult to tabulate. It is shown that results for the cutoff wavelengths can be obtained using simple new formulas relating the ellipse (or circle) to an inscribed polygon. Cutoff wavelengths for the p... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Characteristics of dielectric-tube-loaded coaxial cables

    Publication Year: 1972, Page(s):523 - 528
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (553 KB)

    A study of the complete mode spectrum of the dielectric-tube-loaded coaxial cable reveals that only the low-loss slow-wave TM01 mode has no lower cutoff frequency. Mode designations are shown to be consistent with those previously adopted for dielectric waveguides. A numerical optimisation procedure is applied to an accurate perturbation analysis of the dominant mode to determine optimum dielectri... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Microwave model of an instrument-landing-system glidepath

    Publication Year: 1972, Page(s):529 - 536
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1132 KB)

    A 1/30th scale model of the international standard instrument-landing-system glidepath is described. Interference effects on the linearity of the path in space are investigated, and a theoretical analysis is applied which confirms the integrity of the model operation. The effects due to aircraft taxying in typical airport regions have been measured using accurate scale models of common civil aircr... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Solution to the approximation problem for a class of 2-variable resonant ladder networks

    Publication Year: 1972, Page(s):537 - 540
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (356 KB)

    By using the results on explicit formulas for element values in 1-variable ladder networks dependent on one or two auxiliary parameters, and by using appropriate frequency transformations, certain generalisations may be made to 2-variable networks. For the solution to the approximation problem, which results in an elliptic function or Cheby¿shev response, nonreciprocal 2-variable networks result,... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Production of transient-current waves with long time constants for test purposes

    Publication Year: 1972, Page(s):541 - 547
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (790 KB)

    A development in laboratory bench-testing facilities for protective schemes is described. Test benches used at present contain linear inductors which have high X/R ratios so that offset transients associated with power systems may be simulated. However, owing to losses in the test network, these transients cannot be satisfactorily reproduced at large currents. It is shown here that by replacing th... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Erratum: Optimal control of synchronous-machine excitation by quasilinearisation techniques

    Publication Year: 1972
    IEEE is not the copyright holder of this material | PDF file iconPDF (88 KB)
    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Erratum: Effect of pollution on high-voltage outdoor insulators

    Publication Year: 1972
    IEEE is not the copyright holder of this material | PDF file iconPDF (88 KB)
    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Remote measurement of phase angle

    Publication Year: 1972, Page(s):548 - 556
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1401 KB)

    A system is described for the measurement of the phase angle between two voltages separated from each other, and from the point where the results are to be displayed, by a distance of several miles. A correction for the transmission delay of the measurement signals is automatically made, and an accurate knowledge of the transmission-path characteristics is not required. At power frequencies, the m... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Minimisation of reactive-power installation in a power system

    Publication Year: 1972, Page(s):557 - 563
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (729 KB)

    Reactive-power installations at suitable points become necessary in most modern high-voltage networks, to prevent excessive voltage drops at load busbars. In the paper, the minimisation of the total required reactive-power installation is formulated as a nonlinear-programming problem. Based on certain specific features of this problem, a new solution technique, which results in a considerable redu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improvement of current-transformer transient performance

    Publication Year: 1972, Page(s):564 - 568
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (476 KB)

    The simplest way of improving protective-current-transformer performance during transients is to make the transformer's magnetising inductance relatively low. This method may diminish transient errors but always increases steady-state errors. If the maximum acceptable transient error is defined, the primary current that may be transformed during the transient within the error limits depends on the... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Method of determining power-frequency current distribution in cylindrical conductors

    Publication Year: 1972, Page(s):569 - 574
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (718 KB)

    An approximate, but accurate and conceptually simple, computer-oriented method for determining the distribution of alternating current in cylindrical conductors is presented in the paper. Although general in principle, the method particularly lends itself to the analysis of power-frequency current distribution, i.e. to cases in which the skin effect is not extremely pronounced. The integral equati... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of the external thermal resistance of buried cables through conformal transformation

    Publication Year: 1972, Page(s):575 - 586
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1322 KB)

    The calculation of the outside thermal resistance of a buried cable system related to uniform, nonuniform and temperature-dependent resistivity of soil can be made, if a suitable transformation of the thermal field is automatically drawn and the resistance is computed on the transformed field. A suitable conformal transformation is analysed giving rise to maps of the transformed field. On the maps... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of asymmetrical faults in synchronous generators by d-q-0 frame of reference

    Publication Year: 1972, Page(s):587 - 595
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (685 KB)

    The paper describes the development of a mathematical model in the d-q-0 frame of reference for the analysis of unbalanced operation of synchronous machines. The equations for faults between two phases and between one line and the generator neutral are described. The solution of the equations of the model by digital computer is presented. Initially, the model neglects nonlinearities and subtransie... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • IEE Conference Publication 82 (International medium-voltage-earthing practices)

    Publication Year: 1972
    IEEE is not the copyright holder of this material | PDF file iconPDF (170 KB)
    Freely Available from IEEE
  • IEE Conference Publication 83ߝPt. 1 (Metalclad switchgear)

    Publication Year: 1972
    IEEE is not the copyright holder of this material | PDF file iconPDF (170 KB)
    Freely Available from IEEE
  • Measurement of inductance coefficients of saturated synchronous machines

    Publication Year: 1972, Page(s):597 - 602
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (683 KB)

    In order to employ a coupled-circuit approach for the accurate prediction of the performance of a synchronous machine, it is necessary to know the winding-inductance variations with the machine currents. The paper describes simple techniques by which these variations can be determined in terms of a resultant direct-axis or equivalent field current, and which thereby enable the complete nonlinear i... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Divided-winding-rotor synchronous generators

    Publication Year: 1972
    IEEE is not the copyright holder of this material | PDF file iconPDF (178 KB)
    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimum Lyapunov functions and stability regions for multimachine power systems

    Publication Year: 1972, Page(s):603 - 604
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | PDF file iconPDF (335 KB)
    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal control of linear time-invariant systems with polynomial-type measurable disturbances

    Publication Year: 1972, Page(s):605 - 611
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (630 KB)

    The optimal control of a linear time-invariant multivariable system with an integral quadratic index of performance and with measurable polynomial-type disturbances occurring in both the output and state derivative is considered in the paper. It is shown that the optimal control consists of a feedback controller and a feedforward controller. The feedback controller is the same feedback controller ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Estimation of transfer function of continuous system from sampled data

    Publication Year: 1972, Page(s):612 - 614
    Cited by:  Papers (8)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (421 KB)

    The problem of the estimation of the transfer function of a continuous system based on the observation of sampled input and output data is considered. The paper deals mainly with the online determination of the continuous-system transfer function from a linear discrete model obtained from the data. A number of different digital-analogue transformations are considered, and a comparison is made of t... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Relationship between Box-Jenkins-Åström control and Kalman linear regulator

    Publication Year: 1972, Page(s):615 - 620
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (691 KB)

    The Box-Jenkins-Åström minimum-variance control law for univariate linear stochastic systems is summarised. A minimum-expected-quadratic-loss feedback control law for the same system is derived using state-space theory. Subject to conditions sufficient for the control laws to exist, both theories are shown to give the same result in the 1-step-ahead (unit-delay) case. The more general case is di... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-matrix solutions for the linear optimal regulator

    Publication Year: 1972, Page(s):621 - 624
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (467 KB)

    Algebraic expressions, containing only real matrices, are derived for the solution of the multivariable-optimal-linear-regulator problem for a constant plant and quadratic performance index. They enable both the time-varying-or constant-feedback gains and the plant state and input variables to be computed at any required instant without the need to integrate the differential equations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Regions of transient stability for power systems involving saliency using the Popov criterion

    Publication Year: 1972, Page(s):625 - 628
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (400 KB)

    The Popov criterion has previously been applied to power systems involving round-rotor machines. Here the method is exploited to obtain regions of transient stability for a single-machine system taking into account the effects of saliency. The generalised Popov criterion, which applies to systems with more than one nonlinearity, is used. The resulting regions of stability are shown to approximate ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

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

Full Aims & Scope