Showing papers in "Electrical Engineering in 1958"
TL;DR: In this paper, the effect of the sun and altitude of the line on the current carrying capacity of transmission lines has been considered and a great deal of test work has been performed in the investigation of this problem on ACSR.
Abstract: THE CONTINUOUS current-carrying capacity of transmission lines is dependent upon the allowable temperature of operation of the conductors. A great deal of test work has been performed in the investigation of this problem on ACSR (aluminum cable, steel reinforced). However, two factors—the effect of the sun and of the altitude of the line—have not received consideration heretofore.
107 citations
TL;DR: In this paper, the authors propose a valve point loading system for paralleled turbines to maximize the power generation per pound of steam in preference to equal incremental steam rate loading using smooth average curves.
Abstract: Paralleled turbines should be loaded at selected valve points to maximize the power generation per pound of steam in preference to equal incremental steam rate loading using smooth average curves. The fact that turbines should spend a major portion of their useful working life on valve points instead of in between them, poses a logical question for the turbine and equipment manufacturers. Can valves, valve gear, governors and automatic dispatching equipment be adapted or redesigned to better fit and achieve this more precise and efficient valve point loading system for paralleled turbines?
33 citations
TL;DR: In this paper, the degree of voltage magnification does not necessarily involve circuit-breaker restriking or prestriking, although these factors may increase the severity of the disturbance and may result in system flashovers or equipment damage.
Abstract: MAGNIFICATION of transient voltages in one part of an electric power system may occur in another part of that system, possibly at a different voltage level. Experiences such as these have resulted in system flashovers or equipment damage. The degree of voltage magnification does not necessarily involve circuit-breaker restriking or prestriking, although these factors may increase the severity of the disturbance.
31 citations
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TL;DR: It was felt that it might be conducive of results to analyze the mechanism of the return stroke and then, from the factors governing the mechanism, try to synthesize the stroke.
Abstract: IN RECENT YEARS renewed interest has developed in the effect of lightning on electrical transmission lines. The most vital characteristic of lightning in most methods of calculating its effect is the current measured at the ground terminal. A large amount of data is available about the stroke current crest magnitude and a considerable amount of data is available which covers the time-to-crest of the stroke current. Despite these data there is still controversy over the time-to-crest. Measurements in the region of a microsecond are admittedly difficult. The industry is still seeking new data. In approaching this problem, it was felt that it might be conducive of results to analyze the mechanism of the return stroke and then, from the factors governing the mechanism, try to synthesize the stroke. Perhaps certain limits to the rate of rise could be ascertained. Some of the characteristics of the component factors could be obtained in the laboratory, others by computation. It was with this in mind that the present investigation was undertaken.
29 citations
TL;DR: The opportunities open to engineers to move into positions of management are hampered by a lack of knowledge of the requisites of leadership and ignorance of the art of human relations.
Abstract: The opportunities open to engineers to move into positions of management are hampered by a lack of knowledge of the requisites of leadership and ignorance of the art of human relations. Basic rules are set forth that to be effective must be put into practice until they become habit.
22 citations
Abstract: This paper outlines the method of determining the economic choice which is believed to be universally applicable, mathematically rigorous, and quantitatively correct to the extent permitted by the accuracy with which component items of cost can be forecast. It introduces no drastic innovations, and may be described simply as a better organization of well-established principles. However, it does demonstrate that a number of generally accepted conclusions and procedures are unsound. It points out the advantages of distinguishing between selecting the economic choice and capital budgeting; it discusses difficulties that arise when analysts attempt to solve problems in the first category by applying techniques appropriate to the latter. The paper demonstrates that the economic choice is the alternative having minimum present worth of revenue requirements; i.e., the revenues needed to earn a rate of return acceptable to investors after paying all expenses. It describes the solution to problems in engineering economy in two steps: 1. Determining which alternative is most economic, and by how much. 2. Selecting the most desirable plan, in the light of step 1, plus other factors not reducible to dollars. It is shown that this approach is equally appropriate for regulated utilities and nonregulated industry. The paper also discusses practical applications of this technique to long-range estimates as they are encountered in system planning, as well as means of anticipating the effect of future changes in price levels.
19 citations
TL;DR: In this article, a new type of generator is described, the output frequency, phase angle, and torque angle of which are independent of the shaft speed, which is automatically in synchronism with the system voltage, and the breakers can be opened and closed without any synchronizing equipment.
Abstract: A new type of generator is described, the output frequency, phase angle, and torque angle of which are independent of the shaft speed. The generator is automatically in synchronism with the system voltage, and the breakers can be opened and closed without any synchronizing equipment.
19 citations
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TL;DR: The attitude control is necessary or desirable for at least the following reasons: 1. To provide mental and physical comfort for passengers; 2. to provide proper environment and positioning to allow instrumentation to function; and 3. To ensure proper alignment for lift surfaces and thrust vectors as discussed by the authors.
Abstract: THE PROBLEM of attitude control exists to a certain extent with all kinds of vehicles, missiles, and projectiles. Attitude control is necessary or desirable for at least the following reasons: 1. To provide mental and physical comfort for passengers. 2. To provide proper environment and positioning to allow instrumentation to function. 3. To provide proper alignment for lift surfaces and thrust vectors.
14 citations
TL;DR: Interference between radar transmitters and microwave communication systems is a grewing problem complicated by the fact that the fermer use power output of megawatts, whereas microwave transmitters use power outputs of 10 watts or less.
Abstract: It is the purpose of this paper to discuss the growing problem of interference between radar transmitters and microwave communication systems and the urgent need for the application of measures to enable these two radio services to coexist in the microwave spectrum. The problem basically is a difficult one since the radar transmitters use power outputs measured in megawatts, whereas the microwave transmitters normally use powers of 10 watts or less. The Bell System became aware of this problem as the result of a number of cases of interference to its microwave communication systems from radar operations. Two general types of interference are involved: 1. that resulting from the operation of radars directly on fundamental frequencies used for communication services, and 2. that due to the generation and radiation by the radars of spurious frequencies including harmonics which fall in bands and on frequencies used for communication services. The former type of interference can be eliminated through control of the frequency assignments for both radar and communication purposes. The latter type, however, is not so readily disposed of.
14 citations
TL;DR: The compensation distance relaying (CDF) scheme as discussed by the authors is a different approach to the problem of relaying interphase faults on transmission lines, in which no one relay is assigned to any particular phase.
Abstract: THE COMPENSATOR distance relaying scheme is a new and different approach to the problem of relaying interphase faults on transmission lines. It differs from conventional distance relaying in that no one relay is assigned to any particular phase. Instead, one polyphase unit responds to all phase-to-phase faults, and a second polyphase unit responds to 3-phase faults. Between the two of these units, one or the other or both will respond to any 2-phase-to-ground within the desired zone of protection.
11 citations
TL;DR: In this paper, the authors discuss the effect of turbine-generators on the continuity of power supply over large areas, and propose an alarm mechanism to be used upon the detection of generator ground faults which in themselves do not cause immediate disability of the generator.
Abstract: THE INCREASING SIZE of turbine-generators on large power supply systems means that a sudden loss of a unit tends to endanger the continuity of power supply over large areas. Because of this, some operating companies prefer to sound an alarm upon the detection of generator ground faults which in themselves do not cause immediate disability of the generator. The unit is then taken out of service at the first opportunity.
TL;DR: In this paper, the basic information presented will stimulate further interest in a field of great potential value in the last decade from the sanctuary of the research laboratory into the domain of practical applied science.
Abstract: Infrared has emerged in the last decade from the sanctuary of the research laboratory into the domain of practical applied science. It is hoped the basic information presented will stimulate further interest in a field of great potential value.
TL;DR: More than 14 circuit miles of 230kv oil-filled underground cable were recently placed in service in Vancouver, B. C., Canada as discussed by the authors and a description of the two types of cable used, as well as installation details are given.
Abstract: More than 14 circuit miles of 230-kv oil-filled underground cable were recently placed in service in Vancouver, B. C., Canada. A description is given of the two types of cable used, as well as installation details.
TL;DR: Even though a lightning arrester is connected on the high voltage side of the transformer, surge voltages transferred to the low voltage side can be dangerous especially to lower BIL equipments such as rotating machines and dry type transformers as mentioned in this paper.
Abstract: ALTHOUGH a low-voltage circuit, connected to the system by a transformer, has no direct exposure to lightning, lightning surge voltages can be produced in this circuit as a result of surge voltage impact on the high-voltage side of the transformer. Even though a lightning arrester is connected on the high-voltage side of the transformer, surge voltages transferred to the low-voltage side can be dangerous especially to lower BIL equipments such as rotating machines and dry-type transformers.
TL;DR: In this article, the thermal response of the oil and windings of a transformer will follow a repetitive cycle after one or more cycles, which is known as cyclic thermal response.
Abstract: MANY TRANSFORMERS are called upon to supply varying loads in normal service. In some cases these loads are cyclic in nature. After one or more cycles the thermal response of the oil and windings will also follow a repetitive cycle.
Journal Article•
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TL;DR: The General Electric Extra-High-Voltage Project (called "Project ehv" for short) involves the design, construction, and operation of a complete a-c transmission system which will carry power at voltages from 460 to 750 kv.
Abstract: THE GENERAL ELECTRIC Extra-High-Voltage Project (called “Project ehv” for short) involves the design, construction, and operation of a complete a-c transmission system which will carry power at voltages from 460 to 750 kv. This system will be a prototype of future extra-high-voltage systems. Data obtained from the system will be integrated with analytical studies, model investigations, and laboratory research in all interested components of the participating companies.
TL;DR: In this article, the utility and economics of thermoelectric refrigeration and the reversible features of room temperature control, as based upon the present state of the art, are analyzed.
Abstract: The thermodynamic principles involved in the area governing heat pump phenomena are set forth. The utility and economics of thermoelectric refrigeration and the reversible features of room temperature control, as based upon the present state of the art, are analyzed.
TL;DR: In this paper, an APPARATUS was developed for detecting and locating the presence of small voids or air pockets in rubber or plastic cable insulation, especially in cases where the operating voltage of the cable is high enough to ionize the gas in these void spaces, because continued ionization may eventually erode or burn its way through the insulation, and result in cable failure.
Abstract: AN APPARATUS has been developed for the purpose of detecting and locating the presence of small voids or air pockets in rubber or plastic cable insulation. This is especially important in cases where the operating voltage of the cable is high enough to ionize the gas in these void spaces, because continued ionization may eventually erode or burn its way through the insulation, and result in cable failure.
TL;DR: The application of performance criteria in the analysis, and more particularly in the synthesis, of servo systems is a matter of importance, but it is one of considerable difficulty as compared with the application of stability criteria as mentioned in this paper.
Abstract: THE APPLICATION of performance criteria in the analysis, and more particularly in the synthesis, of servo systems is a matter of importance, but it is one of considerable difficulty as compared with the application of stability criteria. Although it is generally agreed that concise criteria of performance are desirable, there has been no general agreement as to what criteria should be used. This is not too surprising, for surely there should be many criteria to fit the various requirements of different servos.
TL;DR: In this paper, two variations of liquid displacement are possible, i.e., cross-field displacement and co-field displacements, which may be either partially immersing two rod-like electrodes in a liquid dielectric or co-firing energized electrodes made of parallel screens in the liquid.
Abstract: STUDIES of pure liquid dielectrics under the influence of relatively intense electric fields reveal a phenomenon of mass transfer. Two variations of liquid displacement are possible. One is called cross-field displacement. It may be produced by partially immersing two rod-like electrodes in a liquid dielectric. The other is called co-field displacement. This type of mass transfer may be produced by immersing energized electrodes made of parallel screens in the dielectric liquid. Fig. 1 shows a simple cell for cross-field displacement.
TL;DR: In this article, the results of engineering and laboratory studies on the use of water as a coolant for direct cooling of the copper conductors of turbine-generator stator windings are presented.
Abstract: THIS ARTICLE presents the results of engineering and laboratory studies on the use of water as a coolant for direct cooling of the copper conductors of turbine-generator stator windings. Table I compares the relative rates of heat removal by several fluids under similar conditions that are practical for employment in turbine-generators.
TL;DR: In this paper, a description of the counter circuitry being developed to record the Micrometeorite bombardment of artificial earth satellites can be found, and a detailed description is given.
Abstract: Micrometeorite bombardment of artificial earth satellites can be recorded through the use of counters. A description is given of the counter circuitry being developed to record this data.
Journal Article•
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TL;DR: The scope of the discussion to follow will be restricted by omitting consideration of specific instruments, such as inertial components, platforms, etc., and concentrate on the over-all problem of electrical and mechanical design of parts, components, and systems.
Abstract: A GREAT DEAL OF ATTENTION is being paid to the celestial mechanics of space flight and the synthesis of systems to control space vehicles, satellites, and missiles. However, no less important is the problem of the practical design and construction of the vehicles and control hardware which will be required to realize our current potentialities in meeting the challenge of space travel. The scope of the discussion to follow will be restricted by omitting consideration of specific instruments, such as inertial components, platforms, etc., and concentrate on the over-all problem of electrical and mechanical design of parts, components, and systems. Consideration will be given to the physical design of control systems as well as power systems required to provide motivating energy. The attributes of reliability and accuracy will also be treated insofar as they affect the aforementioned topics.
TL;DR: A description of a system of air surveillance and control in which flight data from radars and other relevant information is gathered and evaluated continuously and automatically to present a current picture of the air situation.
Abstract: The sage (semiautomatic ground environment) system is a system of air surveillance and control designed to aid in the air defense of the continental United States. In this system of air surveillance, flight information is transmitted from radars and other sources to a central point where it is processed and evaluated to form a comprehensive picture of the air situation. This picture covers the search area of several radars, thus providing centralized surveillance of a sizable geographic area. The provision of this surveillance capability requires the evaluation of a large amount of information. In addition, to be of any practical use, the surveillance picture must not lag the actual air situation by any very appreciable interval of time. To accomplish this, the flight information must be gathered and evaluated very rapidly. This has been accomplished by minimizing the use of human beings in the surveillance system and leaning heavily on automatic methods. The various automatic data units in the SAGE System are, however, geographically scattered and must be interconnected so that they can process and exchange the flight information. This interconnection is made by special communication systems called data transmission systems which will be described herein.
TL;DR: In this paper, the use of aluminum in power transformers above 10,000 kva has been studied, and the results show that aluminum is more suitable for transformer windings than copper.
Abstract: DURING THE EARLY 1940's copper was in short supply in many countries, with the result that aluminum came into use in power transformer windings as a means of conserving copper. Since that time, there has been a continued interest in aluminum for transformer use. Considerable literature has been published on the use of aluminum in reactors, dry-type transformers, and distribution transformers. Less data has been available on the use of aluminum in power transformers above 10,000 kva. It is these larger sizes that are now under study.
TL;DR: A fully automatic, world-wide switching system is being engineered by Western Union for the United States Air Force to meet the need for rapid and secure transmission of large volumes of military traffic over a world- wide network.
Abstract: The 200,000-mile private-wire network of the United States Air Force includes five Plan 51 switching centers in the United States, leased from The Western Union Telegraph Company. These centers are interconnected by trunk lines and each center has lines radiating to tributary stations in its area. Gateway centers near the Atlantic and Pacific coasts extend the network over radio channels to numerous Air Force installations overseas. This network has been in operation since February 1951. Satisfactory experience in operating this network, with its push-button-operated Plan 51 switching centers, has led the Air Force to request Western Union to engineer a fully automatic switching system for world-wide use. It is expected that automatic switching will increase the speed and efficiency of message handling and result in considerable reduction in operating labor. It will also provide for additional circuit capacity.
TL;DR: In this article, the attitude control problem is reduced to a damping problem and two methods have been proposed to obtain a stable attitude: gravity gradient stabilization and aerodynamic torques.
Abstract: THE AGE OF SATELLITES is here. With it has come some interesting attitude control problems. For many uses, it is desirable to have a satellite oriented in a unique attitude with respect to the earth. If such a unique stable attitude exists, the attitude-control problem is reduced to a damping problem. Two methods have been proposed to obtain a stable attitude. These methods use (1) the gradient in the earth's gravitational field, and (2) aerodynamic torques. Each method requires that the vehicle have certain properties. In gravity gradient stabilization, it is necessary that the vehicle have a single axis about which the moment of inertia is a minimum. In the stabilized position, this axis becomes aligned to the vertical.1–4 In aerodynamic stabilization, it is necessary that the center of pressure lie behind the center of mass in the direction of the vehicle's velocity.
TL;DR: Vacuum switches have had an excellent performance record in applications to which they have been assigned, however, because of their rapid development and acceptance, numerous questions and misconceptions about them have arisen as mentioned in this paper.
Abstract: Vacuum switches have had an excellent performance record in applications to which they have been assigned. However, because of their rapid development and acceptance, numerous questions and misconceptions about them have arisen. An attempt is made to provide information which will help to overcome this problem.
TL;DR: In this article, the use of two or more conductors per phase, an arrangement often referred to as bundle conductors, is discussed and tests made to determine stresses on spacers between these conductors are described.
Abstract: Corona losses in transmission lines may be reduced by the use of two or more conductors per phase, an arrangement often referred to as bundle conductors. Tests made to determine stresses on spacers between these conductors are described.