摘要:

During recent years, of the problems which have presented themselves to engineers on electrical transmission and distribution systems, those of voltage and switch control have probably been the most interesting.Supply systems may be classified as either rural or urban; the latter type is that on which the experience and particulars for the preparation of this paper have been obtained. It is believed that the city of Manchester is the first area to have complete automatic voltage regulation, and also supervisory control for its main substations.Some particulars of the investigations made, equipment installed, and results obtained, are given, together with a brief outline of the growth of systems, and reasons why better control of voltage is necessary.It is claimed that, by a careful application of automatically-controlled compensated voltage-regulators in main substations, the voltage on distribution networks may be economically maintained within the permissible limits of ±4 per cent; and that, generally, the voltage variation at individual services may be kept within 4 per cent overall. At the same time, the fluctuations at the secondary terminals of high-voltage power consumers' transformers may be maintained within the limits for low-voltage distribution. Abnormal cases will, however, occur and will require special treatment.The limitation of voltage variation to such a small amount possesses definite technical, economic, and psychological value; and available records over a short period suggest that it also results in increased sales of energy.The value of supervisory control is referred to, and one system is described in some detail.

DOI:10.1049/jiee-1.1934.0042

出版商:IEE    

年代:1934

数据来源: IET

摘要:

This paper discusses the spontaneous excitation of any vibrating system by random impulses, and in particular the spontaneous excitation of an electrical circuit by the chaotic movement of the free electrons within it. With the hypothesis that the average value of the electrical energy in a circuit is equal to the average energy of a molecule, it is shown that the means square value of the voltage across the condenser varies directly as the absolute temperature and inversely as the capacitance. Formulæ are then developed for the response of a thermionic amplifier, of any given characteristic, which is used to record the thermal-agitation voltage. These formulæ are put to searching experimental proof, and satisfactory values of Boltzmann's constant are deduced from the measurements. The effect of temperature is also investigated.Formulæ are then developed for the voltage due to the shot effect; that is, the shock excitation of the anode-circuit impedance by the pattering of the electrons on the anode. Experimentally-determined curves are given of the shot voltage both with and without space-charge limitation. A formula is developed for the shot voltage in working conditions. It appears from this that the signal/noise ratio can be improved by increasing the mutual conductance of valves, provided that the increase is not accompanied by an increased anode current.Finally, the interaction of a radio-frequency carrier voltage with the voltages due to thermal agitation and to the shot effect is discussed.

DOI:10.1049/jiee-1.1934.0050

出版商:IEE    

年代:1934

数据来源: IET

摘要:

The subject matter of this paper deals with coupled oscillators, and shows the application of the phase relationships existing over the range of synchronism to the construction of a 2-phase oscillator. Various methods of coupling, in order to provide the necessary synchronizing e.m.f., are investigated, with a view to obtaining an arrangement which will ensure stable phase relationships between the outputs. The ultimate 2-phase generator evolved is but slightly affected by changes in anode or filament battery voltages, so that the initial calibration is sufficiently accurate for general laboratory work.

DOI:10.1049/jiee-1.1934.0055

出版商:IEE    

年代:1934

数据来源: IET

DOI:10.1049/jiee-1.1934.0056

出版商:IEE    

年代:1934

数据来源: IET