Showing papers on "Voltage optimisation published in 1971"
TL;DR: In this paper, a more direct control of the stability can be achieved by regulating the power input to the turbine, which is achieved by simultaneous control of field excitation and the turbine.
Abstract: Methods which have been proposed for increasing the margin of stability in large generators generally act by controlling the generator electrical power output. A more direct control of the stability can be achieved by regulating the power input to the turbine. Simultaneous control of the field excitation and the turbine
32 citations
TL;DR: The trend in turbine-generator characteristics as unit sizes become larger is in an adverse direction from the standpoint of power system stability as discussed by the authors, and the effectiveness of independent pole switching and other control measures available to the system planner are shown.
Abstract: The trend in turbine-generator characteristics as unit sizes become larger is in an adverse direction from the standpoint of power system stability. Results of specific studies as well as a general rule of thumb for evaluating this effect are given. The effectiveness of independent pole switching and other control measures available to the system planner are shown.
29 citations
TL;DR: In this article, a simplified linear model describing the voltage and reactive power control characteristics is given which is conveniently constructed for the purpose of minimizing the transmission losses under the constraint of the voltage settling condition.
Abstract: A new and efficient control scheme is proposed for the real-time control of system voltage and reactive power control and the conventional computational algorithms are reviewed from the point of view of on-line centralized control on a real-time basis. A simplified linear model describing the voltage and reactive power control characteristics is given which is conveniently constructed for the purpose of minimizing the transmission losses under the constraint of the voltage settling condition.
21 citations
TL;DR: A modified version of the complex method of Box is used for the minimization of bus voltage deviation in the first phase of optimization and a numerical search technique for the reduction of transmission losses due to reactive power flows in the second phase.
Abstract: An efficient computational algorithm is presented for the real-time control of system voltage and reactive power on the basis of a simplified linear model. A modified version of the complex method of Box is used for the minimization of bus voltage deviation in the first phase of optimization and a numerical search technique for the reduction of transmission losses due to reactive power flows in the second phase. The numerical example for a sample practical system is also given.
15 citations
TL;DR: In this paper, an optimal excitation control for the stability of synchronous machines is found in a closed form using Pontryagin's minimum principle, and the results obtained for the single machine- infinite bus case indicate that such control provides major benefits in removing transients.
Abstract: An optimal excitation control for the stability of synchronous machines is found in a closed form using Pontryagin's minimum principle. While the optimal control is bang bang, in practice it is necessary to compromise with normal voltage regulator action to produce a sub-optimal control. The time required for stabilization is slightly increased by this. The results obtained for the single machine- infinite bus case indicate that such control provides major benefits in removing transients.
13 citations
Patent•
25 Feb 1971
TL;DR: A circuit for use in conjunction with a power supply and which provides a first signal amplitude (e.g., logical ''''1'''') when the voltage output from the power supply is at or above its proper value, and which provided a second signal amplitude when the power input voltage is below its proper values as discussed by the authors.
Abstract: A circuit for use in conjunction with a power supply and which provides a first signal amplitude (e.g., logical ''''1'''') when the voltage output from the power supply is at or above its proper value, and which provides a second signal amplitude (e.g., logical ''''0'''') when the power supply voltage is below its proper value.
12 citations
TL;DR: In this paper, the influence of semiconductors on power sources, other equipment, and the user is discussed, including some new data on the effect of unbalanced firing angles.
Abstract: This article presents data concerning the often ``unmentioned'' influences of semiconductors upon power sources, other equipment, and the user. The influence of methods of power control and the resulting harmonics is considered in detail, including some new data on the effect of unbalanced firing angles. Also presented is information relative to metering accuracy, radio, telephone, and control-circuit interference, lamp flicker, and semiconductor influence, including the characteristics of a new RFI-free switching device. In addition, aspects of regulatory agencies are considered, and detailed references for further in-depth study are given.
11 citations
Patent•
04 Jan 1971
TL;DR: In this article, a plurality of voltage boosters connected to a D.C. power supply each stores a quantity of electrical charge while the power supply provides a regulated value of output voltage.
Abstract: A plurality of voltage boosters connected to a D.C. power supply each stores a quantity of electrical charge while the power supply provides a regulated value of output voltage. When the output voltage of the supply decreases below a predetermined value the boosters are sequentially connected to the D.C. supply and return substantially all of the stored charges to the supply, so that the output voltage increases to the regulated value.
10 citations
TL;DR: In this paper, a solid state device using sampling techniques is described for measurement of power system quantities such as power, reactive power, voltamperes and power factor, and an output voltage linearly proportional to the above quantities is provided for continuous control and recording purposes.
Abstract: A solid state device using sampling techniques is described for measurement of power system quantities such as power, reactive power, voltamperes and power factor. An output voltage linearly proportional to the above quantities is provided for continuous control and recording purposes. The speed of response is less than one cycle.
8 citations
TL;DR: In this paper, the authors present the results of measurements on the characteristics of high frequency transient voltages on power station wiring, including amplitude, frequency, impedance, coupling properties and rate of occurrence.
Abstract: The paper presents the results of measurements on the characteristics of high frequency transient voltages on power station wiring. The characteristics described are the amplitude, frequency, impedance, coupling properties and rate of occurrence. The control measures investigated include the use of shielded cables, relocation of wiring grounds and use of surge diverting capacitors.
7 citations
TL;DR: A brief discussion of the effect of applied voltage on induction motor performance and of induction motor starting on system voltage is presented in this article, which facilitates rapid approximation of voltage dip due to across-the-line starting of induction motors.
Abstract: A brief discussion of the effect of applied voltage on induction motor performance and of induction motor starting on system voltage is presented. Charts which facilitate rapid approximation of voltage dip due to across-the-line starting of induction motors are included. For cases where the charts may not be applicable, a systematized method of calculating the voltage dip is presented.
TL;DR: In this article, a computer program for estimating the weight of a high-power dc-to-dc power conditioner as functions of output power, operating frequency, input voltage range, maximum input voltage, and efficiency is described.
Abstract: Aspects of high-power high-voltage power conditioner design and weight estimation relevant to space subsystems are discussed. Weight has become an increasingly important parameter with the advent of larger and more sophisticated spacecraft, especially those for high-power communication. A computer program for estimating the weight of a high-power dc-to-dc power conditioner as functions of output power, operating frequency, input voltage range, maximum input voltage, and efficiency, respectively, is described, including computer-aided design of inductors and transformers. Curves of typical power conditioner weight as functions of the preceding parameters, derived from the power conditioner weight program, are presented.
TL;DR: In this article, a single-phase filter was designed, fabricated, and experimentally evaluated to prevent load-caused transients from reaching the critical power bus, and the results showed that the filter could prevent the externally produced transients in electrical power systems from reaching transient sensitive electronic equipment.
Abstract: Transients in electrical power systems at many installations are found to cause malfunctions in and damage to electronic equipment. Investigations to date indicate that harmful transients are injected into the critical power bus by both external and internal transients producers. Oscilloscope recordings show that the harmful transients consist of oscillatory voltages having predominant frequency components as low as 400 Hertz and high-frequency disturbances in the form of spike voltages as short as 10 ?sec in duration. A study was conducted on the feasibility of developing power filters which could prevent the externally produced transients from reaching transient- sensitive electronic equipment, and prevent load-caused transients from reaching the critical power bus. Based on the findings, a single-phase filter was designed, fabricated, and experimentally evaluated.
TL;DR: A great deal of attention is being given to the problem of using feed-back signals in the excitation systems as mentioned in this paper, and a number of different signals based on the rates of change of voltage, current, power and rotor angle have been either tried or suggested.
Abstract: A great deal of attention is being given to the problem of using feed-back signals in the excitation systems. It has been shown that the transient stability limits improve if signals besides the terminal voltage deviation are fed to the excitation system. A number of different signals based on the rates of change of voltage, current, power and rotor angle have been either tried or suggested. It appears that during the next few years the feed-back signals will play a very important role in the design of excitation systems.