Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68530
E.A. Atwell, A. Shaffer, D.I. Jerrings, J. Linders
Distribution primary conductors which fault to ground rather than to the neutral conductor or other grounded object are known to result in fault currents which are too low to be detected by conventional overcurrent devices. Such faults, however, are shown to result in distorted currents which can be recognized as distinct from other distribution current distortions. The operating theory of a high-impedance fault alarm system (HIFAS) which can detect these low-current faults is presented. Procedures for safely conducting 13 kV line fault tests to confirm the performance of these new relay operating parameters without jeopardizing customer service are described. Test results that confirm the soundness of the detection principle are given.<>
{"title":"Performance testing of the Nordon high impedance ground fault detector on a distribution feeder","authors":"E.A. Atwell, A. Shaffer, D.I. Jerrings, J. Linders","doi":"10.1109/REPCON.1990.68530","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68530","url":null,"abstract":"Distribution primary conductors which fault to ground rather than to the neutral conductor or other grounded object are known to result in fault currents which are too low to be detected by conventional overcurrent devices. Such faults, however, are shown to result in distorted currents which can be recognized as distinct from other distribution current distortions. The operating theory of a high-impedance fault alarm system (HIFAS) which can detect these low-current faults is presented. Procedures for safely conducting 13 kV line fault tests to confirm the performance of these new relay operating parameters without jeopardizing customer service are described. Test results that confirm the soundness of the detection principle are given.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115632664","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68528
E. S. Thomas
The introduction of neutral current detection systems makes the early determination of progressive capacitor unit failure feasible. This is considered to be a valuable supplement to using group fuses as part of a comprehensive distribution capacitor protection system. The author reviews distribution capacitor failures and how the neutral current tripping scheme can be applied. A rational method for the development of neutral current trip settings is presented. It is concluded that neutral trip devices offer an improved method of preventing capacitor case rupture. Settings should be established to accommodate temporary distribution system conditions which could otherwise cause unnecessary operations.<>
{"title":"Determination of neutral trip settings for distribution capacitor banks","authors":"E. S. Thomas","doi":"10.1109/REPCON.1990.68528","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68528","url":null,"abstract":"The introduction of neutral current detection systems makes the early determination of progressive capacitor unit failure feasible. This is considered to be a valuable supplement to using group fuses as part of a comprehensive distribution capacitor protection system. The author reviews distribution capacitor failures and how the neutral current tripping scheme can be applied. A rational method for the development of neutral current trip settings is presented. It is concluded that neutral trip devices offer an improved method of preventing capacitor case rupture. Settings should be established to accommodate temporary distribution system conditions which could otherwise cause unnecessary operations.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129431080","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68532
J.C. Dedman, H. L. Bowles
Several surveys have been conducted with the purpose of determining the history of failure of underground power cables. Typically, these surveys are used to compare data related to cables of various types or installation conditions. The Rural Electrification Administration (REA) has determined that most of the studies have not supplied valid or meaningful information, because neither the vintage of the cables nor their age at failure was considered. In 1988 and 1989, REA conducted a survey which supplied results which are both valid and meaningful. Analysis of the data reported by over 100 rural electrical cooperatives revealed trends related to several variables, such as insulation material and thickness, jacketing, conductor type, and installation methods. The cumulative total of failures, to date, of the cable installed in each year since 1970 was calculated and broken down according to the same variables. The results of the survey are discussed, and recommendations concerning ways that electric utilities can effectively use the results in considering replacement of aged cables are presented.<>
{"title":"A survey of URD cable installed on rural electric systems and failures of that cable","authors":"J.C. Dedman, H. L. Bowles","doi":"10.1109/REPCON.1990.68532","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68532","url":null,"abstract":"Several surveys have been conducted with the purpose of determining the history of failure of underground power cables. Typically, these surveys are used to compare data related to cables of various types or installation conditions. The Rural Electrification Administration (REA) has determined that most of the studies have not supplied valid or meaningful information, because neither the vintage of the cables nor their age at failure was considered. In 1988 and 1989, REA conducted a survey which supplied results which are both valid and meaningful. Analysis of the data reported by over 100 rural electrical cooperatives revealed trends related to several variables, such as insulation material and thickness, jacketing, conductor type, and installation methods. The cumulative total of failures, to date, of the cable installed in each year since 1970 was calculated and broken down according to the same variables. The results of the survey are discussed, and recommendations concerning ways that electric utilities can effectively use the results in considering replacement of aged cables are presented.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123476127","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68521
K. Pham
The author presents an analytical approach making use of a digital computer to design a safe ground mat for high-voltage substations. The approach is based on the IEEE standard 80-Guide for Safety in AC Substation Grounding. Human factor considerations and calculations of step and touch potentials and ground fault current are discussed. Accurate evaluation of ground mat design can be achieved with the use of digital computers, and costly and conservative design can be eliminated. A summary of all input parameters to the ground mat computer-aided design program and output information is provided. Ground mat construction and grounding system performance follow-up are discussed. A sample ground mat design problem is included.<>
{"title":"Design a safe grounding system for rural electric power distribution substations","authors":"K. Pham","doi":"10.1109/REPCON.1990.68521","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68521","url":null,"abstract":"The author presents an analytical approach making use of a digital computer to design a safe ground mat for high-voltage substations. The approach is based on the IEEE standard 80-Guide for Safety in AC Substation Grounding. Human factor considerations and calculations of step and touch potentials and ground fault current are discussed. Accurate evaluation of ground mat design can be achieved with the use of digital computers, and costly and conservative design can be eliminated. A summary of all input parameters to the ground mat computer-aided design program and output information is provided. Ground mat construction and grounding system performance follow-up are discussed. A sample ground mat design problem is included.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114644118","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68516
E. Makram, R. B. Haines, A. Girgis
The authors consider the effect of harmonics on reactive power measurements, and present a novel method for calculating active, reactive apparent, and residual power in nonsinusoidal conditions. The method considers common and uncommon harmonic components of voltage and current waveforms. It properly defines all power components at different harmonic frequencies, such as rotating real power, quadrature power, and the residual power (distortion). Each component is calculated correctly at different frequencies to define its physical meaning. A computer algorithm is developed to calculate all the power components for any distorted voltage and current waveforms. A numerical example is discussed.<>
{"title":"Effect of harmonic distortion in reactive power measurement","authors":"E. Makram, R. B. Haines, A. Girgis","doi":"10.1109/REPCON.1990.68516","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68516","url":null,"abstract":"The authors consider the effect of harmonics on reactive power measurements, and present a novel method for calculating active, reactive apparent, and residual power in nonsinusoidal conditions. The method considers common and uncommon harmonic components of voltage and current waveforms. It properly defines all power components at different harmonic frequencies, such as rotating real power, quadrature power, and the residual power (distortion). Each component is calculated correctly at different frequencies to define its physical meaning. A computer algorithm is developed to calculate all the power components for any distorted voltage and current waveforms. A numerical example is discussed.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132521255","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68529
D. Duckett, C. Mcdonough
Measurement of system and product reliability has become important both in the purchase of new transformers and for the evaluation of existing equipment. The authors provide a guide to making a purchase decision on transformer replacement based on a reliability and economic evaluation. It is concluded that reliability should be included as a factor in the decision to replace or refurbish older transformers. An example of the economic analysis used in the case of replace/refurbish is presented. The key to using reliability as a planning aid is gaining enough data to generate confidence in the results. The sampling methodology presented can be used to obtain data which can be useful in the analysis of future system needs.<>
{"title":"A guide for transformer replacement based on reliability and economics","authors":"D. Duckett, C. Mcdonough","doi":"10.1109/REPCON.1990.68529","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68529","url":null,"abstract":"Measurement of system and product reliability has become important both in the purchase of new transformers and for the evaluation of existing equipment. The authors provide a guide to making a purchase decision on transformer replacement based on a reliability and economic evaluation. It is concluded that reliability should be included as a factor in the decision to replace or refurbish older transformers. An example of the economic analysis used in the case of replace/refurbish is presented. The key to using reliability as a planning aid is gaining enough data to generate confidence in the results. The sampling methodology presented can be used to obtain data which can be useful in the analysis of future system needs.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133855598","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68517
W. Kersting, W. H. Phillips
The authors describe the accurate model of a distribution feeder and its devices that are incorporated into a radial distribution analysis program (RDAP) developed for the personal computer. An example rural distribution feeder is modeled, and the program is used to demonstrate how the feeder voltage profile can be improved. In the case studied, it is shown that the overall voltage profile was improved and the feeder power losses reduced by relocating shunt capacitor banks and one voltage regulator. In addition, the compensator settings of the regulators were changed.<>
{"title":"Modeling and analysis of rural electric distribution feeders","authors":"W. Kersting, W. H. Phillips","doi":"10.1109/REPCON.1990.68517","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68517","url":null,"abstract":"The authors describe the accurate model of a distribution feeder and its devices that are incorporated into a radial distribution analysis program (RDAP) developed for the personal computer. An example rural distribution feeder is modeled, and the program is used to demonstrate how the feeder voltage profile can be improved. In the case studied, it is shown that the overall voltage profile was improved and the feeder power losses reduced by relocating shunt capacitor banks and one voltage regulator. In addition, the compensator settings of the regulators were changed.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122181453","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68523
D. Horňák, D. Zipse
The techniques and methods for maintaining continuous electrical power to petroleum and chemical facilities from two or more utility feeders by an automated bus transfer logic controller system are discussed. The purpose of this system is to reduce transients, torsional forces, inrush currents, and motor stress, while maintaining continuous motor operation when the primary utility source experiences an interruption and the operating facility transfers of the motor load to an alternative source of electrical supply. The economic considerations of maintaining continuity of production during power supply interruptions using a transfer logic controller to supervise bus transfers may be significant. The relay system continuously monitors the alternative source, the load bus and the normal source, and performs the necessary logic for power supply bus transfers in two directions by automatically selecting from either the fast, in-phase, or residual voltage methods. Engineering studies, application considerations, motor control design requirements, installation, and operation of the automated bus transfer controller for a chemical facility are presented and discussed.<>
{"title":"Automated bus transfer control for critical industrial processes","authors":"D. Horňák, D. Zipse","doi":"10.1109/REPCON.1990.68523","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68523","url":null,"abstract":"The techniques and methods for maintaining continuous electrical power to petroleum and chemical facilities from two or more utility feeders by an automated bus transfer logic controller system are discussed. The purpose of this system is to reduce transients, torsional forces, inrush currents, and motor stress, while maintaining continuous motor operation when the primary utility source experiences an interruption and the operating facility transfers of the motor load to an alternative source of electrical supply. The economic considerations of maintaining continuity of production during power supply interruptions using a transfer logic controller to supervise bus transfers may be significant. The relay system continuously monitors the alternative source, the load bus and the normal source, and performs the necessary logic for power supply bus transfers in two directions by automatically selecting from either the fast, in-phase, or residual voltage methods. Engineering studies, application considerations, motor control design requirements, installation, and operation of the automated bus transfer controller for a chemical facility are presented and discussed.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130403413","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68518
C. Brice
The history of distribution system voltage-drop and loss calculation from paper-and-pencil methods to full three-phase power flow calculations using the digital computer is examined, and recommendations to aid the practising engineer in the choice of the best analytical tools are given. Methods discussed include an approach that allows unbalanced operation (such as an open-wye line) to be analyzed accurately. It is suggested that intelligent use of the models will entail using the more detailed models only if necessary, thereby avoiding unnecessary computational expense. It is much more important to use a reasonable value for the load power factor than to account exactly for every small unbalance in the line impedances.<>
{"title":"Voltage-drop calculations and power-flow studies for rural electric distribution lines","authors":"C. Brice","doi":"10.1109/REPCON.1990.68518","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68518","url":null,"abstract":"The history of distribution system voltage-drop and loss calculation from paper-and-pencil methods to full three-phase power flow calculations using the digital computer is examined, and recommendations to aid the practising engineer in the choice of the best analytical tools are given. Methods discussed include an approach that allows unbalanced operation (such as an open-wye line) to be analyzed accurately. It is suggested that intelligent use of the models will entail using the more detailed models only if necessary, thereby avoiding unnecessary computational expense. It is much more important to use a reasonable value for the load power factor than to account exactly for every small unbalance in the line impedances.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130494120","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}
Pub Date : 1990-04-29DOI: 10.1109/REPCON.1990.68522
L. King, J. I. Pryma, G. S. Spisak, W.D. Wilkens
The latest trends and anticipated future developments in power, control, and communication cables that are expected to impact the design, construction, and maintenance of power distribution systems in rural areas are discussed. Developments relating to medium-voltage power cable, control and instrumentation cables, communication wire and cable, and supervisory control and data acquisition systems are considered. The probable impact of optical fiber technology is discussed.<>
{"title":"Future proofing your system with power, control and communication cables","authors":"L. King, J. I. Pryma, G. S. Spisak, W.D. Wilkens","doi":"10.1109/REPCON.1990.68522","DOIUrl":"https://doi.org/10.1109/REPCON.1990.68522","url":null,"abstract":"The latest trends and anticipated future developments in power, control, and communication cables that are expected to impact the design, construction, and maintenance of power distribution systems in rural areas are discussed. Developments relating to medium-voltage power cable, control and instrumentation cables, communication wire and cable, and supervisory control and data acquisition systems are considered. The probable impact of optical fiber technology is discussed.<<ETX>>","PeriodicalId":174823,"journal":{"name":"34th Annual Conference on Rural Electric Power","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129853563","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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