Methods for transmission and distribution system reliability analysis currently being developed and used require that the expected values of component outage rates and outage durations be known. The paper describes ho...
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Methods for transmission and distribution system reliability analysis currently being developed and used require that the expected values of component outage rates and outage durations be known. The paper describes how the required component parameters can be estimated from field data. Also described are methods of placing confidence limits on the parameters estimated. The methods presented were developed through a study of six years of field records provided by a utility company. Sample expected outage rates and outage durations for various components such as transmission lines, substation transformers, and circuit breakers are presented. Also presented are data which tend to confirm the distributional assumptions made in system reliability analysis methods.
It is shown that pi representation of gap in center conductor of transmission line is much more realistic and accurate than common practice of considering circuit equivalent of gap as capacitance in series with center...
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It is shown that pi representation of gap in center conductor of transmission line is much more realistic and accurate than common practice of considering circuit equivalent of gap as capacitance in series with center conductor, which is probably inadequate for many purposes;such representation is not difficult to determine since it is evident that values of equivalent capacitances involved can be calculated directly from physical dimension of circuit by existing and wellestablished procedures;while procedures involved in representing such gaps by pi networks may be more involved than for series capacitance representations, superior results may well be worth it, and in fact may be required in some cases. (10339)
An expression for the radiation resistance of a cylinder is derived, following the "tangential field" or "induced electromotive force" method as adapted by Pistolkors. The result is used to determi...
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An expression for the radiation resistance of a cylinder is derived, following the "tangential field" or "induced electromotive force" method as adapted by Pistolkors. The result is used to determine the radiation resistance of a segment of a concentric cylinder transmission line, as used in ultra-high-frequency oscillator circuits. A comparision is made with the more conventional parallel wire line segment. Numerical computations are made for the case of a line one-half wavelength long, with a radius (for the concentric line) and a spacing (for the open line) of one-twentieth of a wavelength. These are believed to be the largest dimensions to be encountered in practice. The resistances are, respectively, 0.086 ohm and 3.02 ohms, showing the concentric line to be definitely superior as far as radiation losses are concerned.
When two overhead conductors a few inches a part are used for each phase of a transmission line circuit, instead of one larger conductor, the reactance is reduced 20 per cent or more. Where voltage drop determines the...
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A method of producing frequency modulation is described wherein an eighth-wave radio-frequency transmission line is used as a modulation device. One end of the transmission line serves as a part of the tank circuit of...
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A method of producing frequency modulation is described wherein an eighth-wave radio-frequency transmission line is used as a modulation device. One end of the transmission line serves as a part of the tank circuit of the oscillator while at the other end is placed a variable resistance, such as a vacuum tube. Absolute linearity may be obtained with negligible amplitude modulation. A brief description of different types of transmission lines used is also given.
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