{"title":"The author's reply to the discussion on 'A sensitive recording magnetometer'","authors":"A. Butterworth","doi":"10.1049/JI-2.1947.0103","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0103","url":null,"abstract":"","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116196667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The author's reply to the discussion on 'The growing importance of plastics in the electrical industry'","authors":"G. Haefely","doi":"10.1049/JI-2.1947.0095","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0095","url":null,"abstract":"","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114126802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The merits of plastics, strikingly demonstrated during the war, and the expectations attached to their peace-time developments, justify a special paper on their importance as dielectrics to those electrical engineers who, during the last few years of intensive professional activity, have not found time to keep themselves informed on general progress. The history of plastics in relationship to the industry is referred to and an attempt is made to explain, in a simple manner, the fundamental chemical structure of some typical materials, with the intention of stimulating a desire for a deeper knowledge of this young and expanding science. Since the electrical industry could not have reached its present importance in everyday life without these new plastic insulating substances, the chief consideration is given to their particular function of solving new problems, and of improving existing electrical apparatus by taking the place of older materials. The principal plastics are briefly discussed without, however, entering into detailed descriptions of their manufacture or properties. A small section has been devoted to the service which plastics can render the installations engineer.
{"title":"The growing importance of plastics in the electrical industry","authors":"G. Haefely","doi":"10.1049/JI-2.1947.0093","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0093","url":null,"abstract":"The merits of plastics, strikingly demonstrated during the war, and the expectations attached to their peace-time developments, justify a special paper on their importance as dielectrics to those electrical engineers who, during the last few years of intensive professional activity, have not found time to keep themselves informed on general progress. The history of plastics in relationship to the industry is referred to and an attempt is made to explain, in a simple manner, the fundamental chemical structure of some typical materials, with the intention of stimulating a desire for a deeper knowledge of this young and expanding science. Since the electrical industry could not have reached its present importance in everyday life without these new plastic insulating substances, the chief consideration is given to their particular function of solving new problems, and of improving existing electrical apparatus by taking the place of older materials. The principal plastics are briefly discussed without, however, entering into detailed descriptions of their manufacture or properties. A small section has been devoted to the service which plastics can render the installations engineer.","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130959721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new sensitive recording magnetometer, suitable for measuring changes in any component of the earth's magnetic field, is described. The changes in field are recorded by making a continuous record of the resultant impedance variations of a length of Mumetal wire situated in the field to be studied.
{"title":"A sensitive recording magnetometer","authors":"A. Butterworth","doi":"10.1049/JI-2.1947.0101","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0101","url":null,"abstract":"A new sensitive recording magnetometer, suitable for measuring changes in any component of the earth's magnetic field, is described. The changes in field are recorded by making a continuous record of the resultant impedance variations of a length of Mumetal wire situated in the field to be studied.","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127906621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The authors' reply to the discussion on \"A millisecond chronoscope\"","authors":"R. Spilsbury, A. Felton","doi":"10.1049/JI-2.1947.0100","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0100","url":null,"abstract":"","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121636156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A brief account is given of an investigation of lightning disturbances on the Electricity Supply Board's system in Ireland. Figures for the average lightning faults per 100 miles of line per annum for the 110-, 38- and 10-kV systems are derived from a 10-year record of such faults. Using the records of the 10-kV system as a basis, the author constructs a map showing the variation of lightning trouble intensity for different localities in Ireland. An account is also given of some magnetic link observations of lightning surges on the earth leads from 110-kV overhead earthwires and from 38-kV lightning arresters. The results obtained appear to show that a large proportion of the discharge currents of such arresters have values below 1 000 amp. Since the usual practice has been to mount magnetic links so that only currents in excess of about 3 000 amp are recorded, it would seem that many arrester operations may have escaped detection, and the results of such observations could therefore lead to erroneous conceptions as to the frequency of operation of medium-voltage arresters. Since modern lightning technique is largely a question of the economics of individual applications, the author stresses the importance of obtaining adequate local lightning data wherever possible.
{"title":"Lightning surges on transmission lines in Ireland","authors":"R. C. Cuffe","doi":"10.1049/JI-2.1947.0088","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0088","url":null,"abstract":"A brief account is given of an investigation of lightning disturbances on the Electricity Supply Board's system in Ireland. Figures for the average lightning faults per 100 miles of line per annum for the 110-, 38- and 10-kV systems are derived from a 10-year record of such faults. Using the records of the 10-kV system as a basis, the author constructs a map showing the variation of lightning trouble intensity for different localities in Ireland. An account is also given of some magnetic link observations of lightning surges on the earth leads from 110-kV overhead earthwires and from 38-kV lightning arresters. The results obtained appear to show that a large proportion of the discharge currents of such arresters have values below 1 000 amp. Since the usual practice has been to mount magnetic links so that only currents in excess of about 3 000 amp are recorded, it would seem that many arrester operations may have escaped detection, and the results of such observations could therefore lead to erroneous conceptions as to the frequency of operation of medium-voltage arresters. Since modern lightning technique is largely a question of the economics of individual applications, the author stresses the importance of obtaining adequate local lightning data wherever possible.","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125067290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Introduction deals with the characteristics of systems having insulated and earthed neutral points.The elementary theory of the Petersen-coil system is then considered. The two main effects of the coil are neutralization of the leading component of the fault current and slowing down of the rate of rise of recovery voltage (r.r.r.v.) across the fault arc. The effect of system leakage resistance upon the residual fault current is also discussed.The author then considers the effect of unsymmetrical line capacitances in causing an excessive voltage on the neutral of a healthy system. Slight detuning of the coil may be necessary to reduce this voltage, and there is a possibility of unwanted operation of protective gear.Consideration of the effect of fault impedance on the fault and coil currents shows that normal values of fault resistance have a negligible effect upon the fault current, which is primarily determined by the tuning of the coil. Accurate tuning increases the sensitivity of the indicating gear to high-resistance faults and limits the power loss at the fault. The behaviour of reactive as distinct from resistive faults is discussed.The possibility of freak resonant effects during abnormal circuit conditions, such as the opening of one phase only, due to conductor breakage or non-simultaneous clearing of circuit breakers, is mentioned. Saturation of the iron core of the coil keeps unwanted resonance within safe limits, but abnormal operation of indicating gear may sometimes be attributed to these effects.The theory of arc extinction in Petersen-coil systems is then expounded, and the effect of resistance damping and tuning factor upon the r.r.r.v. across the fault is dealt with.A method of calculating the system capacitance to earth is given, together with formulae for 3-phase lines with and without earth wires. The effect of line series reactance, and the behaviour of electrically long lines, are considered. The Appendices contain general formulae.The application of Petersen coils to double-circuit and parallel lines is dealt with. A fault on one circuit impresses a voltage on the neutral of the adjacent healthy circuit. Probable values of this voltage are indicated and the advantages of compensating the mutual capacitance between circuits by means of “decoupling” and “suction” coils are analysed. Practical methods are suggested for tuning star-connected earthing and suction coils.
{"title":"The theory and operation of Petersen coils","authors":"J. Sumner","doi":"10.1049/JI-2.1947.0091","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0091","url":null,"abstract":"The Introduction deals with the characteristics of systems having insulated and earthed neutral points.The elementary theory of the Petersen-coil system is then considered. The two main effects of the coil are neutralization of the leading component of the fault current and slowing down of the rate of rise of recovery voltage (r.r.r.v.) across the fault arc. The effect of system leakage resistance upon the residual fault current is also discussed.The author then considers the effect of unsymmetrical line capacitances in causing an excessive voltage on the neutral of a healthy system. Slight detuning of the coil may be necessary to reduce this voltage, and there is a possibility of unwanted operation of protective gear.Consideration of the effect of fault impedance on the fault and coil currents shows that normal values of fault resistance have a negligible effect upon the fault current, which is primarily determined by the tuning of the coil. Accurate tuning increases the sensitivity of the indicating gear to high-resistance faults and limits the power loss at the fault. The behaviour of reactive as distinct from resistive faults is discussed.The possibility of freak resonant effects during abnormal circuit conditions, such as the opening of one phase only, due to conductor breakage or non-simultaneous clearing of circuit breakers, is mentioned. Saturation of the iron core of the coil keeps unwanted resonance within safe limits, but abnormal operation of indicating gear may sometimes be attributed to these effects.The theory of arc extinction in Petersen-coil systems is then expounded, and the effect of resistance damping and tuning factor upon the r.r.r.v. across the fault is dealt with.A method of calculating the system capacitance to earth is given, together with formulae for 3-phase lines with and without earth wires. The effect of line series reactance, and the behaviour of electrically long lines, are considered. The Appendices contain general formulae.The application of Petersen coils to double-circuit and parallel lines is dealt with. A fault on one circuit impresses a voltage on the neutral of the adjacent healthy circuit. Probable values of this voltage are indicated and the advantages of compensating the mutual capacitance between circuits by means of “decoupling” and “suction” coils are analysed. Practical methods are suggested for tuning star-connected earthing and suction coils.","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121662859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The author's reply to the discussion on \"Lightning surges on transmission lines in Ireland\"","authors":"R. C. Cuffe","doi":"10.1049/JI-2.1948.0017","DOIUrl":"https://doi.org/10.1049/JI-2.1948.0017","url":null,"abstract":"","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131016050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper opens with a discussion of various methods of measuring short time intervals and then proceeds to describe a condenser chronoscope suitable for the measurement of intervals initiated and terminated by momentary or sustained makes or breaks in electrical circuits. The range is from 2 millisec to 1 000 millisec. The voltage on the condenser is measured by a simple valve voltmeter which is used only as a transfer iastrument, the final reading being given on three decade dials of a potentiometer. This reading is converted into milliseconds by the use of specially prepared tables. The instrument is self-contained and transportable, power being obtained from dry batteries. The accuracy, which is limited chiefly by dielectric absorption in the condenser and by leakage in the components, is of the order of 0.5 millisec on short intervals or 0.5% on long intervals.
{"title":"A millisecond chronoscope","authors":"R. Spilsbury, A. Felton","doi":"10.1049/JI-2.1947.0098","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0098","url":null,"abstract":"This paper opens with a discussion of various methods of measuring short time intervals and then proceeds to describe a condenser chronoscope suitable for the measurement of intervals initiated and terminated by momentary or sustained makes or breaks in electrical circuits. The range is from 2 millisec to 1 000 millisec. The voltage on the condenser is measured by a simple valve voltmeter which is used only as a transfer iastrument, the final reading being given on three decade dials of a potentiometer. This reading is converted into milliseconds by the use of specially prepared tables. The instrument is self-contained and transportable, power being obtained from dry batteries. The accuracy, which is limited chiefly by dielectric absorption in the condenser and by leakage in the components, is of the order of 0.5 millisec on short intervals or 0.5% on long intervals.","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116266624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The authors' replies to the discussion on \"The extinction of arcs in air-blast circuit-breakers\" and \"The performance of high-voltage oil circuit-breakers incorporating resistance switching\"","authors":"A. Allan, D. F. Amer, H. E. Cox, T. W. Wilcox","doi":"10.1049/JI-2.1947.0107","DOIUrl":"https://doi.org/10.1049/JI-2.1947.0107","url":null,"abstract":"","PeriodicalId":307627,"journal":{"name":"Journal of the Institution of Electrical Engineers - Part II: Power Engineering","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1947-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121955800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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