From a linear analysis of a tunnel diode loaded with a transmission line, it is shown that oscillations highly stable in frequency are possible. Preliminary experimental results are in agreement with the theory. Stabi...
详细信息
From a linear analysis of a tunnel diode loaded with a transmission line, it is shown that oscillations highly stable in frequency are possible. Preliminary experimental results are in agreement with the theory. Stability on the order of one part in 10/SUP 5/ is easily attained.
This paper outlines the fundamentals of a method of obtaining overall protection of transmission lines by a comparison of the relative direction of fault current flow at the line ends by means of a communication syste...
详细信息
This paper outlines the fundamentals of a method of obtaining overall protection of transmission lines by a comparison of the relative direction of fault current flow at the line ends by means of a communication system. The results obtained are equivalent to differential protection. The carrier-current pilot or d-c pilot wire schemes which have been introduced during the past few years are applications of this method. The optional use of a communication system to link the trip circuits at the ends of a transmission line provided with any conventional form of relay protection is described. This insures the simultaneous tripping of both line ends for all fault positions. The various types of communication systems adaptable for relay purposes are described and discussed in regard to coordination with the telephonic communication, telemetering or supervisory control systems employed as adjuncts of the power system. Copyright 1933. By A. I. E. E.
A theory of a ferromagnetic traveling-wave amplifier of parametric type is presented here. Amplification of signal power in the form of growing waves is obtained in a propagating structure which is partially or totall...
详细信息
A theory of a ferromagnetic traveling-wave amplifier of parametric type is presented here. Amplification of signal power in the form of growing waves is obtained in a propagating structure which is partially or totally embedded in a ferromagnetic medium. The structure, in one of its possible forms, possesses two propagating modes: one of the modes is excited by a signal at the input end, and the other is used as an idling circuit. The structure should also support a traveling wave supplied by a local oscillator which provides, through the motion of the magnetization, a time-varying coupling between the two propagating modes. The problem is essentially that of two coupled transmission lines with a time-dependent coupling coefficient. Optimum conditions for amplification are derived. A structure consisting of two pairs of parallel wires is calculated to illustrate the general principles.
An exact analysis is made for the shielded coupled strip transmission line with three center conductors. By means of the immittance matrices presented, the electrical behavior of the coupled strip transmission line of...
详细信息
An exact analysis is made for the shielded coupled strip transmission line with three center conductors. By means of the immittance matrices presented, the electrical behavior of the coupled strip transmission line of this type may be completely described. Design formulas which enable one to evaluate the cross-section dimensions from the desired values of characteristic immittances are derived for the two kinds of the line configurations. Equivalent circuits of the two-port networks for various port conditions are also presented. In addition, an application is discussed involving the asymmetrical coupled strip transmission line with two center conductors. The appendix gives the derivation of the design formulas by means of conformal mapping techniques.
Review of the Subject.—This paper covers the design of the 110-kv. transmission line to transmit energy from the new Oak Grove development of the Portland Railway, Light and Power Company to the city of Portland, Ore...
详细信息
Review of the Subject.—This paper covers the design of the 110-kv. transmission line to transmit energy from the new Oak Grove development of the Portland Railway, Light and Power Company to the city of Portland, Oregon, a distance of 54 miles. The company now has three hydroelectric developments aggregating 52,000 kw. supplied from the same general watershed from which energy is transmitted to Portland over five 60-kv. circuits, only one of which is on steel towers. The problem was to design a transmission line to most economically handle the three 30,000-kv-a. units as installed at the new development and to tie in with the existing transmission system. The following factors were considered in determining the design: 1. Transmission voltage 2. Conductor capacity 3. Maximum conductor tension 4. Assumed maximum mechanical loading conditions 5. Type of supporting structures Consideration was also given to the physical characteristics of the country through which the line must be built. For 14.8 miles the line will be located in the United States Government Forest Reserve, which is very heavily timbered, and accordingly cost of clearing will be very high, averaging $15,000 a mile, even after credit for merchantable timber is allowed. This fact, outside of other considerations, required a minimum number of circuits. To reduce clearing costs as much as possible, the line was located along the river gorge necessitating 55 angles, a few as great as 60 deg., and 28 river crossing spans, varying from 400 to 1800 feet. After considering various types of supporting structures, three types of double circuit, heavy rigid steel towers were decided upon as follows: Type A towers, to be used on tangents up to 800-foot spans, also on curves up to 10 deg., the spans not exceeding 500 feet;suspension insulators to be used. Type B towers, to be used on tangents up to 1700-foot spans, also on curves from 8 to 30 deg., the spans not exceeding 800 feet for the larger curves;suspension in
暂无评论