Showing papers on "Electric power system published in 1969"
TL;DR: In this article, a centralized optimizing computational algorithm for the on-line control of voltage and reactive power is presented, where the body of the paper is divided into two parts: the main body is devoted to the analysis and the body is dedicated to the implementation of the algorithm.
Abstract: This paper presents a centralized optimizing computational algorithm for the on-line control of voltage and reactive power. The body of the paper is divided into two parts.
107 citations
Book•
15 Aug 1969
76 citations
TL;DR: In this paper, a model of the power system load with the generation system model is proposed to calculate the availability, frequency of occurrence, and mean duration of the generation reserve states, and the results of this work are illustrated by continuation of a simple numerical example.
Abstract: This paper is a continuation of the work started in [1] and is aimed at incorporating a model of the power system load with the generation system model developed previously. Combination of this load and the generation model permits computation of the availability, frequency of occurrence, and mean duration of generation reserve, or margin states. The results of this work are illustrated by continuation of a simple numerical example begun in Part I. The most widely applied of the previously developed techniques for assessing generation system reliability, the loss-of-load and loss-of-capacity methods, assume fixed outage or load duration intervals. The present model, on the other hand, uses an exponential distribution of durations. The reserve margin states developed using the exponential distributions contain data giving both the availability of each margin state and the expected frequency of recurrence. Previous methods yield only the availability of the reserve margin states, or else availability and frequency data for generating capacity states, not considering the load. The method presented and illustrated may be extended t o consider the calculation of operating reliability or the inclusion of the effects of a simple transmission system.
68 citations
TL;DR: In this article, the effects of line loading and its power factor on the voltage and current profiles of the line and ganerator excitation have been included, and the inevitability of power-frequency overvoltages during faults is established.
Abstract: This paper provides additional theoretical information on half-wave-length power transmission. The analysis is rendered more general by consideration of a natural half-wave line instead of a short line tuned to half-wave. The effects of line loading and its power factor on the voltage and current profiles of the line and ganerator excitation have been included. Some of the operating problems such as charging of the line and synchronization of the half-wave system are also discussed. The inevitability of power-frequency overvoltages during faults is established. Stability studies have indicated that the use of switching stations is not beneficial. Typical swing curves are also presented.
67 citations
TL;DR: In this article, the feasibility of solving optimal load flow problems by means of nonlinear programming techniques has been previously demonstrated, and a new method by Powell for constrained minimization has claimed a better performance than existing methods.
Abstract: The feasibility solving optimal load flow problems by means of nonlinear programming techniques has been previously demonstrated. Recently, a new method by Powell for constrained minimization has claimed a better performance than existing methods. An investigation was carried out to test Powell's method on optimal load flow problems and results obtained confirm expectations. Powell's method and its accompanying Fletcher-Powell method, which performs the actual minimizations, are presented. The power system optimal load flow problem is discussed, and its equations are presented in the form required by the nonlinear programming approach. Finally, a numerical example on the IEEE 30- bus standard test system is presented in which an economic dispatching is accomplished with the new method. Computation time is small enough to permit the application of the method for dispatching at practical intervals of time.
62 citations
TL;DR: Control of rotating exciters to improve system damping has been carried forward in pilot applications to evaluate practicality, effectiveness, alinement needs, and operating characteristics.
Abstract: Control of rotating exciters to improve system damping has been carried forward in pilot applications to evaluate practicality, effectiveness, alinement needs, and operating characteristics. The first application to this type of exciter system has been in operation since July 1967. These pilot applications include exciters with rotating amplifier regulators and with static regulators. Information yield has been high. New control requirements have been indicated and satisfied. Tests and alinement procedures, application criteria, and auxiliary techniques have been developed. Results have been gratifying.
40 citations
01 Feb 1969
TL;DR: An iterative indirect approach based on the Lagrange-Kuhn-Tucker conditions of optimality is presented, and a small sample system of part of the British 275/132kV network is solved.
Abstract: The optimisation of power-system operating conditions is formulated as a general mathematical programming problem. All the system voltages, active and reactive generations and transformer tap settings are considered as independent variables, with network equations represented by equality constraints, and system operating limits by inequality constraints. An iterative indirect approach to the problem based on the Lagrange-Kuhn-Tucker conditions of optimality is presented, and the computer program is described briefly. A small sample system of part of the British 275/132kV network is solved.
40 citations
Abstract: The valve-point loading logic described in this paper is intended to meet at any time in the most economical fashion a generation commitment. This objective is approached by insuring that as great a portion of the load as practicable will be carried by units loaded to valve points, that the remainder of the load will be carried by units reserved for regulation, and that in both categories the assignments will be made to those units which can provide the requisite capacity at the lowest cost.
38 citations
TL;DR: In this article, the prime-mover speed governors function principally as stabilizers, automatic power-frequency control taking over the job of maintaining tie-line power schedules, frequency, and time.
Abstract: During normal operation the prime-mover speed governors function principally as stabilizers, automatic power-frequency control taking over the job of maintaining tie-line power schedules, frequency, and time. The prime importance of dead band is reemphasized. During disturbances governors affect both frequency drop and relatively long-term power swings, but generation schedules are of equal importance in certain cases.
26 citations
26 citations
TL;DR: In this paper, a Markov chain representation of the generation system and load model is used to estimate the loss of load probability and frequency and duration of a generator's operation, and the results of two previous papers are used to develop the planning technique.
Abstract: This paper provides a description of a generation system planning technique employing Markov chain representations of generation system and load models. The results of two previous papers, which described methods for calculating generation system reserve margin states, are used to develop the planning technique. Studies of generation system expansion using the technique are described. For the first time, numerical relationships are developed between generation system reliability measured by the "loss-of-load probability" method and the "frequency and duration" method. Sample load statistics representing many company years of data are offered in substantiation of the load model.
01 Jan 1969
TL;DR: During normal operation the prime-mover speed governors function principally as stabilizers, automatic power-frequency control taking over the job of maintaining tie-line power schedules, frequency, and time.
Abstract: During normal operation the prime-mover speed governors function principally as stabilizers, automatic power-frequency control taking over the job of maintaining tie-line power schedules, frequency, and time. The prime importance of dead band is reemphasized. During disturbances governors affect both frequency drop and relatively long-term power swings, but generation schedules are of equal importance in certain cases.
TL;DR: It is shown that the area dispatch computers, upon the formation of power pools, can form a multicomputer configuration and a computer hierarchy is presented.
Abstract: It is the major objective of this paper to present the use of multicomputer configurations in the dispatch of real power in power pools. It is shown that the area dispatch computers, upon the formation of power pools, can form a multicomputer configuration. The characteristics of such a configuration are outlined and a computer hierarchy presented. Both the single-area as well as the multiarea approaches to the power dispatch problem are formulated and their associated modeling described. A number of novel methods for the instant-by-instant dispatch of real power are given. Three multiarea methods are described in detail which have been called 1) pool boundary cost iteration method, 2) pool ?ratio method, and 3) pool base point and participation factor method.
TL;DR: In this article, a specific interpretation of the new American National Standard application guides for ac highvoltage circuit breakers, as an aid to obtaining uniform results when making short-circuit studies of industrial-plant power systems is described.
Abstract: A specific interpretation of the new American National Standard application guides for ac high-voltage circuit breakers, as an aid to obtaining uniform results when making short-circuit studies of industrial-plant power systems is described. A technique is introduced for interpolation when the major sources of industrial-plant short-circuit current include both local generators and a tie from the utility.
TL;DR: In this article, the effect on critical lines, produced by removing a line from service or by changing the generation schedule, can be determined as an on-line function of a computer that is installed in the system operator's office.
Abstract: A method has been developed suitable for on-line evaluation of contingencies that requires a relatively small computer. The effect on critical lines, produced by removing a line from service or by changing the generation schedule, can be determined as an on-line function of a computer that is installed in the system operator's office. The method can also be used by system planning personnel to reduce the number of detailed power flow cases that must be made in an expansion study.
TL;DR: In this article, a unified method for power system reliability calculations is presented for determining the availabilities and frequencies of occurence of the capacity states which may arise with multiple boiler-turbines or with recognition of the forced partial outage states of unit-connected boiler turbines, and a comparison is offered of the effects of lumping partial capacity outages into equivalent total forced outages upon generation system reliability predictions.
Abstract: The presentation of a unified method for power system reliability calculations is continued. Techniques are presented for determining the availabilities and frequencies of occurence of the capacity states which may arise with multiple boiler-turbines or with recognition of the forced partial outage states of unit-connected boiler-turbines. A comparison is offered of the effects of lumping partial capacity outages into equivalent total forced outages upon generation system reliability predictions. Several numerical examples are shown to illustrate the methods developed. For several examples studied, simple equivalents with a reduced number of states were developed which were found to be excellent approximations to the complete Markov chain description of the stochastic processes involved.
TL;DR: A detailed sensitivity analysis is made of a particular system under various operating conditions, and results are tabulated, making it possible to obtain a clear idea about the effect of any parameter on the system performance and dynamic stability limit.
Abstract: Modern control theory is being used more and more in regulator design of synchronous generator automatic regulating equipment. Making use of the well-established linearized equations of the synchronous machine and its control equipment, the characteristic equation of the system is developed from which the eigenvalues of the system are found. The sensitivities of these eigenvalues to the various parameters of the control system are calculated. This approach can provide a basis for optimal design of the system. A detailed sensitivity analysis is made of a particular system under various operating conditions, and results are tabulated, making it possible to obtain a clear idea about the effect of any parameter on the system performance and dynamic stability limit.
TL;DR: In this article, the development of a new type of solid-state protective relay which senses both frequency and rate of change of frequency is outlined, and the design considerations and principles of operation of this relay are explained with respect to modern load reduction concepts.
Abstract: The development of a new type of solid-state protective relay which senses both frequency and rate-of-change of frequency is outlined The design considerations and principles of operation of this relay are explained with respect to modern load reduction concepts The theory of operation of the device and how it can be applied in an electric power system are discussed Finally, possible future applications of the philosophy of rate compensated protection are presented
TL;DR: In this paper, the authors present techniques and methods for conducting simplified power-flow calculations in power pools by employing the simultaneous computing capability of the computers in the separate areas of the pool.
Abstract: Techniques and methods are presented for conducting simplified power-flow calculations in power pools by employing the simultaneous computing capability of the computers in the separate areas of the pool.
Patent•
03 Jan 1969
01 Nov 1969
TL;DR: In this article, the problems associated with determining the duty of circuit breakers in industrial power systems, and particularly the contribution made by induction motors, are reviewed and compared with calculated induction-motor fault contributions.
Abstract: The paper reviews the problems associated with determining the duty of circuit breakers in industrial power systems, and considers particularly the contribution made by induction motors. Original test results are presented and compared with calculated induction-motor fault contributions. A simple empirical method for calculation is proposed, and results of a survey of constants for 415V and 3.3kV motors are given. Current switchgear specifications are considered in relation to their application to industrial systems, to show those points which require special attention.
TL;DR: In this paper, the authors present a review of the more feasible and promising concepts for propellant transfer in orbit and discuss their compatibility with typical refueling requirements, including determining vapor-liquid interface stability, pressurant requirements, transfer-line chilldown, receiver-tank thermodynamics, propellant-transfer dynamics and associated nonsteady flow problems, and dielectrophoresis.
Abstract: URING the last 20 years, in-flight refueling of military aircraft has become routine. The extension of this operational technique to earth-orbital spacecraft will become mandatory as mission durations are extended up to one year and beyond. This paper reviews the more feasible and promising concepts for propellant transfer in orbit and discusses their compatibility with typical refueling requirements. Several analyses are presented which relate to determining vapor-liquid-interface stability, pressurant requirements, transfer-line chilldown, receiver-tank thermodynamics, propellant-transfer dynamics and associated nonsteady flow problems, and dielectrophoresis. A simplified concept for estimating suction specific speeds of low-NPSH (net positive suction head) pumps is given. Finally, two figures of merit are suggested for use in system tradeoffs, one for the transfer system only and one for the over-all tanker vehicle. Propellant Transfer System Concepts Tank replacement is an obvious method for transferring small to moderately large quantities of propellants. Quickdisconnect couplings would be utilized to minimize required extra-vehicular activity (EVA) on the part of the astronauts. This concept appears to be attractive for resupply of life support fluids and for transferring small quantities of propellants.
TL;DR: In this paper, the system performance characteristics of 765-kV versus 345kV transmission are discussed, and the system planning studies, analyses, and considerations that led to the adoption of 7 65 kV transmission as a new EHV overlay for the American Electric Power system to be superimposed on the existing 345-kv transmission network are described.
Abstract: The system performance characteristics of 765-kV versus 345-kV transmission are discussed, and the system planning studies, analyses, and considerations that led to the adoption of 765- kV transmission as a new EHV overlay for the American Electric Power system to be superimposed on the existing 345-kV transmission network are described.
01 Aug 1969
TL;DR: In this article, the optimal control of transients in a nonlinear power system by means of the new approach of bang-bang control of reactance is investigated, and the generality and utility of this control process are discussed and computational results are presented for a specific case.
Abstract: This letter investigates optimal control of transients in a nonlinear power system by means of the new approach of bang-bang control of reactance. The generality and utility of this control process are discussed and computational results are presented for a specific case.
TL;DR: In this article, the authors present a concise summary of results obtained from a rigorous analysis of the factors influencing the transient fault currents in an EHV rectifier terminal for a fault on the line side of the dc series reactor.
Abstract: This paper presents a concise summary of results obtained from a rigorous analysis of the factors influencing the transient fault currents in an EHV rectifier terminal for a fault on the line side of the dc series reactor. The effect of the exact instant of fault occurrence after the time of completion of a commutation is shown to have special significance. It is also shown that the maximum transient peak currents, even for an "instantaneous" control system, may be on the order of 2.0 times nornal or more for representative dc series inductances when initial load is considered. For a less ideal or slower control system, greater maximum peak transient fault currents are found. Furthermore, saturation of the dc series reactor is shown to result in larger currents. Results for two and three bridges in series, as well as for a single bridge, are given in curve form for convenience of the user.
TL;DR: In this paper, the block diagram reduction technique for reliability analysis is reviewed and compared with the use of the state transition matrix, and it is pointed out that an efficient technique now exists for calculating system mean time between failures directly from the transition matrix.
Abstract: The block diagram reduction technique for reliability analysis is reviewed and compared with the use of the state transition matrix. It is pointed out that an efficient technique now exists for calculating system mean time between failures directly from the transition matrix, and this fact removes the major advantage possessed by the reduction technique. The superior flexibility of analysis using the transition matrix and the fewer approximations that are necessary seem to favor this approach for further power system applications.
TL;DR: In this paper, Pan-Africanism-Land and Power is discussed in the context of the culture of revolution in the Black Scholar: Vol. 1, The Culture of Revolution, pp. 36-43.
Abstract: (1969). Pan-Africanism-Land and Power. The Black Scholar: Vol. 1, The Culture of Revolution, pp. 36-43.
TL;DR: In this paper, a computer program concept is described for performing an electrical analysis and a transient thermal analysis of a satellite electric power subsystem consisting of a solar array, battery, and power controls.
Abstract: A computer program concept is described for performing an electrical analysis and a transient thermal analysis of a satellite electric power subsystem consisting of a solar array, battery, and power controls. The program "flies" the power subsystem and certain thermally sensitive portions of the spacecraft through one or more complete orbits, and plots curves of voltages, currents, temperatures, and energy balance in critical parts of the power and thermal subsystems.
TL;DR: The decision to introduce 765 kV on the American Electric Power (AEP) system is related to the general development of EHV transmission in this country and abroad as discussed by the authors.
Abstract: The decision to introduce 765 kV on the American Electric Power (AEP) system is related to the general development of EHV transmission in this country and abroad. In 1952 AEP pioneered in developing 345-kV transmission as an overlay to the then existing 138-kV system and is now pioneering in the development of 765-kV transmission as an overlay to both the 345- and 138-kV systems to assure a fully integrated operation. Load growth, reliability, prudent use of land and rights-of-way, and economics of EHV transmission are discussed as related to the decision to construct the 765-kV system.