摘要:

A test pressure vessel for the investigation of electrical discharges in gases at pressures up to 1 000 lb/in2is described.The electrical insulating properties of compressed air, nitrogen, dichlorodifluoromethane (commercially known as Freon 12 or Arcton 6) and sulphur hexafluoride, as well as certain mixtures of these gases, are compared; a hemispherically-tipped point-to-plane electrode configuration and direct voltages were used. Pronounced maxima obtained in the spark-breakdown-voltage/gas-pressure characteristics for the electronegative gases and gas mixtures are shown to be associated with the establishment of corona at the anode.Corona-current/voltage characteristics for some of the gases tested are included.

DOI:10.1049/pi-2.1953.0169

出版商:IEE    

年代:1953

数据来源: IET

摘要:

The paper reviews electric-winder characteristics and winding practice with particular reference to the degree of control required for satisfactory automatic winding, and considers the shortcomings of equipments not fitted with means of effecting complete speed/load compensation and controlled electrical retardation.The degrees of automatic control are defined, together with those requirements of a winding engine which are essential to satisfactory control. How these requirements can be achieved with both Ward Leonard and a.c. equipments by incorporating the latest developments in control technique is suggested, and results of tests taken on automatic winders in France are quoted.Having reviewed the problems of control, the paper outlines automatic winding applications, showing how control can be effected for both skip and cage winding and the advantages to be derived.

DOI:10.1049/pi-2.1953.0170

出版商:IEE    

年代:1953

数据来源: IET

摘要:

After setting out some of the problems of metering, such as choosing the best meter rating for the job. determining the optimum period at which meters are removed for cleaning and recalibration, etc., it is emphasized that, wherever possible, the approach should be on the basis of economics.Since no rational solutions can be found without adequate information about consumers' load characteristics, including the spread of the actual consumption over the load range of meters, a pilot investigation on operational-research lines has been arranged.Under the aegis of the Utilization Research Committee of the British Electricity Authority and Area Boards, a sample of 110 domestic consumers was drawn from a large urban area, and a novel load-analysing meter and a demand indicator were installed with each of them for a year concurrently.From the data obtained, supplemented by previous E.R.A. work, it is suggested that for installed loads of up to 40 amp, a meter of nearest (but not lower) maximum continuous rating should be chosen, whereas for all higher loads encountered so far, a meter of 40-amp m.c.r. would be sufficient.With the particular meter sizes used in the area concerned, just under 13% of the total consumption was found to have been taken while the individual consumers' loads did not exceed 10% of the normal ratings of the meters, and only 8% while these ratings were exceeded. Analysis by meter size showed the load sub-ranges in which the highest concentrations of consumption might be expected. From a composite picture of the distribution of consumption at various loads it emerges that as much as one-third of the total annual consumption was taken while the individual consumers' loads did not exceed 5 amp, and well over one-half while they were below 10 amp, whereas less than one-tenth was taken at loads exceeding 20 amp.These findings apply only to conditions similar to those in the area sampled. It is hoped that many more sample tests will be conducted, enabling comprehensive load/consumption characteristics to be derived on which to base rational decisions on future meter policy.

DOI:10.1049/pi-2.1953.0175

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0176

出版商:IEE    

年代:1953

数据来源: IET

摘要:

The impregnated pressure cable has a mass-impregnated dielectric which is maintained under a nitrogen pressure of 200 lb/in2without an intervening membrane.After a survey of the installations which have been completed in Great Britain and of its increasing usage abroad, the modern design of the cable and its electrical and pneumatic accessories is described.Incidents which have occurred in service since the first commercial application of the cable system in 1940 are given in full detail. These include electrical faults, gas leakage and the effects which result from movement of the cable impregnant.Service experience and laboratory tests have shown that the system is sound but that its pneumatic performance, although adequate, is capable of improvement. The significance of pneumatic incidents in relation to the correct planning of the system is discussed.Prospective developments which will assist in improving pneumatic characteristics are indicated.Since the first commercial installation of impregnated pressure cable in 1940, about 140 feeder miles have been commissioned in Great Britain, and important installations are in progress abroad.Operational experience is detailed and the prospect of further improvement is discussed.

DOI:10.1049/pi-2.1953.0179

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0182

出版商:IEE    

年代:1953

数据来源: IET

摘要:

The design of transductors for dimming discharge lamps gives rise to certain problems whose solution is of interest in a wider field of application. The combination of these non-sinusoidal devices raises in an acute form the question of the general validity of transductor characteristic curves. It is shown that within certain limitations the use of these characteristics is justified. The wide range of load current required in this application is discussed in connection with the magnetic properties of the core material. Some of the effects of varying the curvature of the knee of the saturation curve are mentioned. Discrepancies between theory and practice are discussed with reference to a specific design.

DOI:10.1049/pi-2.1953.0185

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0197

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0198

出版商:IEE    

年代:1953

数据来源: IET