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# Electrical Engineers, Proceedings of the Institution of

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• ### Effects of eddy currents in transformer windings

Publication Year: 1966, Page(s):1387 - 1394
Cited by:  Papers (463)
| | PDF (829 KB)

The effects of eddy currents in transformer windings are considered, and a method is derived for calculating the variation of winding resistance and leakage inductance with frequency for transformers with single-layer, multilayer and sectionalised windings. The method consists in dividing the winding into portions, calculating the d.c. resistances and d.c. leakage inductances of each of these port... View full abstract»

• ### Application of fuzzy algorithms for control of simple dynamic plant

Publication Year: 1974, Page(s):1585 - 1588
Cited by:  Papers (956)
| | PDF (388 KB)

The paper describes a scheme in which a fuzzy algorithm is used to control plant, in this case, a laboratory-built steam engine. The algorithm is implemented as an interpreter of a set of rules expressed as fuzzy conditional statements. This implementation on a digital computer is used online, to control the plant. The merit of such a controller is discussed in the light of the results obtained. View full abstract»

• ### Fringing field of finite parallel-plate capacitors

Publication Year: 1970, Page(s):1201 - 1204
Cited by:  Papers (2)
| | PDF (368 KB)

The effect of finite plate width on the fringing field of a parallel-plate capacitor is determined, and an exact expression is derived for the total capacitance by applying conformal transformation to a finite parallel-plate configuration. With small values of the plate-width/plate-separation ratio, finiteness of plate width is shown to have a predominant effect on the correction factor for capaci... View full abstract»

• ### Dielectric-fibre surface waveguides for optical frequencies

Publication Year: 1966, Page(s):1151 - 1158
Cited by:  Papers (77)
| | PDF (968 KB)

A dielectric fibre with a refractive index higher than its surrounding region is a form of dielectric waveguide which represents a possible medium for the guided transmission of energy at optical frequencies. The particular type of dielectric-fibre waveguide discussed is one with a circular cross-section. The choice of the mode of propagation for a fibre waveguide used for communication purposes i... View full abstract»

• ### The design of wide-band transistor feedback amplifiers

Publication Year: 1963, Page(s):375 - 389
Cited by:  Papers (186)
| | PDF (1744 KB)

A design technique is developed which apparently overcomes all the limitations of common-emitter transistor video amplifiers. This technique is based on the use of the impedance mismatch which occurs between stages having alternate series and shunt feedback. It is shown that the realizable gain-bandwidth product is in excess of 0.9Â¿T, the gain and bandwidth are insensitive to transistor parameter... View full abstract»

• ### Transient analysis of underground power-transmission systems. System-model and wave-propagation characteristics

Publication Year: 1973, Page(s):253 - 260
Cited by:  Papers (138)
| | PDF (942 KB)

A mathematical model suitable for the analysis of travelling-wave phenomena in underground power-transmission systems is presented. The model is developed in terms of a generalised angular frequency, and may therefore be applied to the solution of steady-state problems or, by means of Fourier-transform techniques, to the solution of transient problems. The model takes into account skin effect in t... View full abstract»

• ### Numerical solution of 2-dimensional scattering problems using a transmission-line matrix

Publication Year: 1971, Page(s):1203 - 1208
Cited by:  Papers (202)
| | PDF (714 KB)

A numerical method using impulse analysis of a transmission-line matrix is introduced and used to obtain wave-impedance values in a waveguide. The method is demonstrated by applying it to the scattering caused by a waveguide bifurcation. View full abstract»

• ### Surface-acoustic-wave components, devices and applications

Publication Year: 1973, Page(s):1078 - 1110
Cited by:  Papers (17)
| | PDF (5201 KB)

Since the mid-1960s, there has been a strong upsurge of interest in the propagation of surface acoustic waves on solids. The stimulus for this interest came from the realisation that simple, compact, and potentially cheap surface-acoustic-wave devices could be made which performed valuable signal-processing functions principally at intermediate frequencies. In a very short space of time these devi... View full abstract»

• ### Relationship between permittivity and loss tangent

Publication Year: 1971, Page(s):244 - 246
Cited by:  Papers (5)
| | PDF (382 KB)

For a dielectric material, it can be proved that the change of permittivity between two frequencies f1 and f2 is given by Â¿Â¿Â¿/Â¿Â¿Â¿1.5 tan Â¿ log10 f2/f1 subject to certain conditions. Many published results, for diverse materials and frequencies, conform to this equation, even when the therotical conditions are not met; but, at microwave frequencies, there are many discrepancies, possibly bec... View full abstract»

• ### Linear time-varying systemsߞstate transition matrix

Publication Year: 1979, Page(s):1331 - 1335
| | PDF (424 KB)

The state transition matrix of a linear time-varying system cannot, in general, be expressed in a closed form and has, therefore, to be evaluated numerically. For the commutative class of linear time-varying systems, the state-transition matrix is the exponential matrix. A numerical procedure is developed for the evaluation of this matrix to any desired degree of accuracy by the method of series e... View full abstract»

• ### Axial magnetic forces in induction motors with skewed slots

Publication Year: 1975, Page(s):149 - 153
Cited by:  Papers (3)
| | PDF (566 KB)

A comprehensive analysis of the axial force experienced by the rotor of an induction motor, as a function of slip, is presented. It is shown that the varying saturation along the stack of a skewed induction motor considerably affects the axial force due to skew. The calculated values obtained for the force are found to compare quite favourably with experimental results. It is also established that... View full abstract»

• ### Application of matrix methods to the solution of travelling-wave phenomena in polyphase systems

Publication Year: 1963, Page(s):2200 - 2212
Cited by:  Papers (193)
| | PDF (1414 KB)

The interest in travelling waves and surge phenomena in power systems has grown considerably because of the relevance to power-line carrier communication and protection, fault location, switching of unloaded lines and the recovery voltages on circuit-breakers under short-line fault conditions. The paper summarizes the solution to the single-conductor wave equation, develops the solution for the 2-... View full abstract»

• ### Roth's method for the solution of boundary-value problems in electrical engineering

Publication Year: 1967, Page(s):1969 - 1976
Cited by:  Papers (8)
| | PDF (1070 KB)

Between the years 1927 and 1938 the French engineer E. Roth developed a powerful method for the solution of boundary-value problems in electrical engineering. He applied the method to problems in heat conduction and magnetic-field problems in electrical machines and transformers, although the application of the method is not necessarily limited to such devices. In spite of its possibilities, the m... View full abstract»

• ### Novel approach to the analysis and synthesis of modulation processes in power convertors

Publication Year: 1975, Page(s):507 - 513
Cited by:  Papers (103)
| | PDF (798 KB)

It is axiomatic that frequency changing, whether it be in communications or power convertors, can only be achieved by a process of modulation. The paper presents a powerful method of analysing and synthesising these complex modulation processes using a 3-dimensional modulation-model approach, which provides a lucid geometric interpretation of the processes involved. The application of the new appr... View full abstract»

• ### Investigation of the load-flow problem

Publication Year: 1968, Page(s):1459 - 1470
Cited by:  Papers (104)
| | PDF (1284 KB)

A mesh approach is developed for the formulation of the network equations in load-flow analysis. It is shown to converge at least as fast as the usual methods using the nodal-impedance matrix. A hybrid approach is then developed, using a combination of an impedance-matrix method and a nodal-admittance-matrix method. The hybrid exhibits very fast convergence, and is the most powerful method encount... View full abstract»

• ### Dynamic model of impulse characteristics of concentrated earths

Publication Year: 1974, Page(s):123 - 135
Cited by:  Papers (103)
| | PDF (1119 KB)

A dynamic model to describe the nonlinear surge-current characteristics of several concentrated earths has been developed. The model accurately accounts for the surge behaviour of these earths on a time-to-time basis, in soils with resistivities ranging from 5000 Â¿ cm to 31 000 Â¿ cm. This results in a significant improvement over the previous methods used to describe them. The use of the new mod... View full abstract»

• ### Magnetic equivalent circuits

Publication Year: 1968, Page(s):1503 - 1511
Cited by:  Papers (38)
| | PDF (1206 KB)

The possibilities of using magnetic, instead of electric, equivalent circuits for eddy-current devices, which have recently been pointed out by Laithwaite, are here explored further. Couplings between distributed flux paths and windings can be expressed in terms of a generalised linkage parameter N, which is associated with flux linkage in electric circuits, and with an analogous current linkage i... View full abstract»

• ### Probabilistic analysis of power flows

Publication Year: 1974, Page(s):1551 - 1556
Cited by:  Papers (57)
| | PDF (712 KB)

The paper describes and examines a technique which permits the power-flow problem in a power system to be analysed probabilistically instead of using normal deterministic methods. All the nodal loads and generation are defined as random variables and the power flow in each line is computed in terms of a probability density function. The expected values and standard deviation of each power flow are... View full abstract»

• ### New technique for beam steering with fixed parabolic reflectors

Publication Year: 1971, Page(s):857 - 863
Cited by:  Papers (25)
| | PDF (835 KB)

A technique is described which offers the potential of achieving wide-angle beam steering with fixed parabolic reflectors. The technique involves a primary-feed device with an aperture field distribution which can be adapted to match the distorted field distributions resulting from a parabolic reflector when an off-axis plane wave is incident. To provide an adaptation without deterioration of the ... View full abstract»

• ### New sinusoidal pulsewidth-modulated invertor

Publication Year: 1975, Page(s):1279 - 1285
Cited by:  Papers (117)
| | PDF (878 KB)

Sinusoidal p.w.m. invertors depend intrinsically for their operation on quite complex modulation processes. An in-depth study of these modulation processes is presented and the sources of possible operational problems are identified. These problems are shown to be manifest in low-frequency harmonic distortion and the possible existence of subharmonics at noninteger frequency ratios, particularly a... View full abstract»

• ### Discrete positive-real functions and their application to system stability

Publication Year: 1969, Page(s):153 - 155
Cited by:  Papers (72)
| | PDF (397 KB)

A class of discrete-time transfer-function matrices termed discrete positive-real matrices is defined, and a system theoretic description of them is given, analogous to that for ordinary positive-real matrices. This description is applied to analysing the stability of a discrete-time system with linear forward part, and time-varying memoryless feedback. View full abstract»

• ### Transverse edge effects in linear induction motors

Publication Year: 1969, Page(s):973 - 979
Cited by:  Papers (15)
| | PDF (701 KB)

Currents in the secondary member of a linear induction motor flow in roughly elliptical paths. The secondary appears to have a resistivity greater than the natural value, and the cross-gap flux density peaks towards the edges of the stators. This phenomenon is known as the transverse edge effect. In most previous work, the edge effect has been allowed for only by the use of a resistivity-increase ... View full abstract»

• ### Method of calculating the electromagnetic field and power losses in ferromagnetic materials, taking into account magnetic hysteresis

Publication Year: 1971, Page(s):1679 - 1685
Cited by:  Papers (6)
| | PDF (805 KB)

The authors consider a method of determining the electromagnetic field and power losses in ferromagnetic materials, using data from measured hysteresis loops. With the help of a GIER digital computer, the distribution of electromagnetic waves in solid iron and in steel sheets has been calculated. The results of these calculations are compared with measurements obtained from tests on samples. View full abstract»

• ### Scattering by a finite cylinder

Publication Year: 1967, Page(s):864 - 868
Cited by:  Papers (10)
| | PDF (642 KB)

Scattering of a plane wave by a finite, conducting, right-circular cylinder is treated by geometrical diffraction theory. Formulas appropriate for calculating radar cross-section as a function of frequency, polarisation, aspect angle and bistatic angle are presented. Calculations for two large cylinders are in very good agreement with monostatic measurements against aspect angle for four linear-po... View full abstract»

• ### Analysis of unbalanced polyphase networks by the method of phase co-ordinates. Part 1: System representation in phase frame of reference

Publication Year: 1968, Page(s):1163 - 1172
Cited by:  Papers (45)
| | PDF (1031 KB)

The analysis of unbalanced-power-system problems depends usually on transformation methods by which the primary or phase quantities are substituted by, for example, symmetrical-component quantities. These transformations have had computational advantages in the past, but with the use of the digital computer, they no longer appear to be necessary. Investigations into system-unbalance problems and t... View full abstract»

• ### Guided complex waves. Part 2: Relation to radiation patterns

Publication Year: 1963, Page(s):325 - 334
Cited by:  Papers (23)
| | PDF (1177 KB)

The presence of complex waves in the near field of a source-excited plane homogeneous interface is shown to play an important role in determining certain features of the radiation field. A Kirchhoff-Huygens integration over the near field reveals that, whenever these complex waves are strongly excited, they account for peaks in the radiation pattern. Under unidirectional excitation, each complex w... View full abstract»

• ### Acoustic noise and vibration of rotating electric machines

Publication Year: 1968, Page(s):1633 - 1640
Cited by:  Papers (19)
| | PDF (1565 KB)

In recent years, with the growing public awareness of acoustic noise and current work towards International and British Standards concerned with noise from rotating electric machines, work on rotating-machine noise has progressed, from attempts at a qualitative explanation of the more obvious components of machine noise, towards the prediction of the complete acoustic spectrum from the design data... View full abstract»

• ### Optimum goodness criterion for linear-induction-motor design

Publication Year: 1976, Page(s):89 - 92
| | PDF (488 KB)

Linear induction motors (l.i.ms) have many possible applications, ranging from low-speed cranes to high-speed ground-vehicle propulsion. However, in average and high-speed l.i.ms, the end effects cause considerable deterioration in the performance in low-slip regions. The paper introduces the concept of realistic goodness factor GR, which takes into account by appropriate coefficients the airgap l... View full abstract»

• ### Method for simultaneous measurement of current and voltage on high-voltage lines using optical techniques

Publication Year: 1976, Page(s):957 - 960
Cited by:  Papers (5)
| | PDF (539 KB)

A laboratory device for the simultaneous measurement of current and voltage on a high voltage busbar has been constructed. A laser beam may be directed upwards from the ground to interrogate a passive optical transducer attached to a high-voltage busbar. Real and reactive power indications can also be obtained from the output, thus providing complete simultaneous information on the line state. The... View full abstract»

• ### Insulating properties of high vacuum

Publication Year: 1965, Page(s):1237 - 1248
Cited by:  Papers (3)
| | PDF (1805 KB)

Recent experimental work on the insulating properties of high vacuum is systematically reviewed. A rÃ©sumÃ© of the prebreakdown conduction phenomena is given; in small gaps, the steady prebreakdown currents appear to be due to a modified type of field emission, while in longer gaps the contamination on the electrode surfaces gives rise to an ion-exchange mechanism, which is responsible for the mic... View full abstract»

• ### TEM wave properties of microstrip transmission lines

Publication Year: 1968, Page(s):43 - 48
Cited by:  Papers (113)
| | PDF (833 KB)

Wave-propagation properties of microstrip transmission lines can be determined accurately if an exact electrostatic-field solution can be found for a pair of charged conductors separated by a dielectric sheet. The latter problem is framed as an integral equation for whose solution simple numerical methods are available. To determine the kernel function of this integral equation, the classical meth... View full abstract»

• ### The goodness of a machine

Publication Year: 1965, Page(s):538 - 541
| | PDF (562 KB)

The action of electromagnetism can be explainedÂ¿ in terms of relativistic corrections to the inverse-square law of electric charges or of any convenient analogy. One of the commonest is that of the electric and magnetic circuits. What constitutes a goodÂ¿ magnetic circuit and a `goodÂ¿ electric circuit in this context is generally recognised, but it is not so easy to define what one means by a ... View full abstract»

• ### Electrical breakdown for uniform fields in compressed gases

Publication Year: 1970, Page(s):269 - 280
Cited by:  Papers (44)
| | PDF (2071 KB)

The electrical breakdown and prebreakdown characteristics of uniform fields in compressed gases are described. The failure of Paschen's law and the dependence of the breakdown voltage on the material, preparation and area of the electrodes, on the dust content of the gas, and on the type of applied voltage are included. The failure of the Townsend and streamer mechanisms of low-pressure breakdown ... View full abstract»

• ### Newton-Raphson algorithm for 3-phase load flow

Publication Year: 1974, Page(s):630 - 638
Cited by:  Papers (25)
| | PDF (969 KB)

One of the problems encountered in power-systems operation is the generation of unbalanced voltages and currents in the presence of long transmission lines with few or no transpositions, including possible unbalances arising in source and load conditions, or indeed any items of plant such as shunt and series reactors. To improve or investigate these unbalance effects in any detail, a 3-phase-load-... View full abstract»

• ### Preliminary investigation of an invertor-fed 5-phase induction motor

Publication Year: 1969, Page(s):980 - 984
Cited by:  Papers (68)
| | PDF (478 KB)

The paper reports some preliminary experiments on an invertor-fed 5-phase induction motor, and shows measured values of instantaneous current and torque. These are compared with the values predicted by a dual analogue. The amplitude of the torque fluctuation is approximately one third of that of the corresponding 3-phase motor. View full abstract»

• ### Coaxial-to-waveguide transition (end-launcher type)

Publication Year: 1976, Page(s):984 - 986
Cited by:  Papers (7)
| | PDF (356 KB)

A general formula for the design of an end-launcher type of transition from a coaxial line to rectangular, as well as a circular waveguide terminated in any arbitrary impedance, is developed. The application of the analysis to some important practical cases is illustrated. View full abstract»

• ### Fast-decoupled three-phase load flow

Publication Year: 1978, Page(s):734 - 740
Cited by:  Papers (24)
| | PDF (716 KB)

Using as a reference the single-phase fast-decoupled algorithm, this paper describes the modifications required to produce an efficient three-phase fast-decoupled load flow. The compound-coil concept is used in the representation of power-system components, and the effect of automatic voltage regulators is modelled as part of the reactive-power Jacobian-matrix equation. It is shown that the three-... View full abstract»

• ### Design of multivariable control systems using the inverse Nyquist array

Publication Year: 1969, Page(s):1929 - 1936
Cited by:  Papers (50)
| | PDF (994 KB)

The inverse Nyquist array is a set of diagrams corresponding to the elements of the inverse of the open-loop transfer function of a control system. A number of theorems are proved which show how this array can be used to investigate the stability of multivariable control systems. The application of the array to the design of such systems is illustrated. View full abstract»

• ### Arc-electrode phenomena

Publication Year: 1971, Page(s):1131 - 1154
Cited by:  Papers (42)
| | PDF (4814 KB)

The paper gives a survey of the most important aspect of arc-electrode processes (excluding externally heated cathodes) which concern engineers in a variety of applications. Although it is not possible to avoid discussion of the basic mechanisms and of the number of conflicting and still unresolved theories for them, the emphasis is, as far as possible, on those characteristics which affect the de... View full abstract»

• ### Guided complex waves. Part 1: Fields at an interface

Publication Year: 1963, Page(s):310 - 324
Cited by:  Papers (70)
| | PDF (2117 KB)

The variety of waves which can be supported by a plane homogeneous interface includes surface waves of the forward and backward type, and several kinds of complex wave, the latter being characterized by wave numbers which are complex even though the media involved are not necessarily lossy. The present study views all these waves as contributions due to poles in several alternative integral repres... View full abstract»

• ### Measurement of earth-electrode resistance with particular reference to earth-electrode systems covering a large area

Publication Year: 1964, Page(s):2118 - 2130
Cited by:  Papers (10)
| | PDF (1337 KB)

The method of measuring an earth-electrode resistance has been known for a number of years, but there are some aspects of the measurement which are not fully understood. In particular, there are difficulties which arise when the earth-electrode system is of large physical dimensions, e.g. that of a substation or power station. The simple method which is normally used cannot be applied directly for... View full abstract»

• ### Scattering parameters of an arbitrarily shaped aperture in a waveguide

Publication Year: 1972, Page(s):1465 - 1466
Cited by:  Papers (1)
| | PDF (258 KB)

An arbitrarily shaped aperture in the wall of a uniform waveguide of unspecified cross-section has been analysed in terms of its scattering and radiating properties, using variational techniques. The method is of general application, the principal requirement being that the Green's functions for the waveguide and the external medium or structure should be known. Attention is focused particularly o... View full abstract»

• ### Root-locus study of synchronous-machine regulation

Publication Year: 1964, Page(s):761 - 768
Cited by:  Papers (10)
| | PDF (796 KB)

The general equations of a synchronous machine, with continuous regulation and connected by tieline to a large system, are reduced by small-departure methods to linear relationships from which is derived the characteristic equation for a particular situation. An examination of the coefficients of this equation over a range of operating levels shows that the results obtained for one operating point... View full abstract»

• ### Design of industrial regulators. Integral feedback and feedforward control

Publication Year: 1972, Page(s):1210 - 1216
Cited by:  Papers (53)
| | PDF (748 KB)

A theory of control and observation for linear constant multivariable systems with constant disturbances is presented that leads to design methods for linear regulators of both integral feedback and feedforward types. The properties of systems having more control inputs than the minimum required to regulate the outputs (systems with redundant controls) are examined. It is shown that the independen... View full abstract»

• ### Rectifiers and rectifier applications. A review of progress

Publication Year: 1963, Page(s):714 - 738
| | PDF (4104 KB)

Very great changes have taken place recently in connection with rectifiers and their applications, and this seems to be a suitable moment to survey the state of world developments and the trends. The rectifiers considered here are limited to those of substantial power, for the ordinary industrial and traction applications. They therefore mainly comprise (i) mercury-arc convertors for wide-range gr... View full abstract»

• ### Self-tuning controller

Publication Year: 1975, Page(s):929 - 934
Cited by:  Papers (130)
| | PDF (814 KB)

A strategy for the design of self-tuning controllers of systems with constant but unknown parameters is presented. A cost function which incorporates system input, output and set-point variations is selected, and a control law for a known system is derived. This control law is shown to comprise a least-squares predictor of a function related to the cost function, and the control input is chosen to... View full abstract»

• ### Theory of loaded scatterers

Publication Year: 1964, Page(s):617 - 623
Cited by:  Papers (44)
| | PDF (803 KB)

A general formulation is given for the problem of electromagnetic scattering by an object having N terminal pairs (or ports) to which N loads or an N-port network is connected. The theory is applicable to back scattering and bistatic scattering, reciprocal and nonreciprocal media, near-field and far-field scattering and passive and active loads. The representation is made in terms of both open-cir... View full abstract»

• ### Flashover mechanism of polluted insulation

Publication Year: 1964, Page(s):985 - 990
Cited by:  Papers (6)
| | PDF (718 KB)

When a leakage current flows over the wet polluted surface of an insulator, high-resistance dry bands form. Discharges across these dry bands usually become extinguished but, exceptionally, may develop into a flashover of the insulator. The formation of dry bands and the subsequent growth of discharges on the polluted surface of a flat-strip insulator have been studied by scanning the voltage dist... View full abstract»

• ### Current/voltage characteristics of p-n Ge-Si and Ge-GaAs heterojunctions

Publication Year: 1966, Page(s):1468 - 1476
Cited by:  Papers (10)
| | PDF (1083 KB)

The current characteristics of solution-grown and vapour-grown p-n Ge-Si and Ge-GaAs heterojunctions have been studied as functions of voltage and temperature. All the junctions studied exhibit a range over which the forward-current characteristics are proportional to exp (AV)Ãexp (Br), where A and B are constants essentially independent of voltage and temperature. Although this is the only type ... View full abstract»

• ### Antenna noise temperature

Publication Year: 1968, Page(s):1403 - 1410
Cited by:  Papers (4)
| | PDF (906 KB)

Expressions for calculating the noise temperature of an antenna are deduced. The influence of the atmosphere and the environment of the antenna are discussed. It appears that analytical expressions for the sky temperature T(Â¿, Â¿) are available. So, if the antenna gain function G(Â¿, Â¿) is also known analytically, it is possible to calculate the noise temperature of the antenna. If G(Â¿, Â¿) is ... View full abstract»

## Aims & Scope

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

Full Aims & Scope