{"title":"A Comparison of a D.C. Common Power System to a D.C. Embedded Power System in Remote Terminal Applications","authors":"K. McMillen, R. Lyon","doi":"10.1109/INTLEC.1987.4794563","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794563","url":null,"abstract":"In the last decade, the Telephone Industry has dramatically changed the methods for providing communication transport from business and residential customers to the local serving telephone office. The standard pairs of wires used for subscriber loops have been rapidly replaced by the use of Subscriber Loop Carrier Systems (SLC® Carrier), electrically combining groups of customers (i.e. 24) on only two pairs of wires instead of a pair per customer. The application of the latest technology has proven to be the most economical media with the added benefits of improved transmission quality and quick response to changing subscriber needs. The SLC Carriers utilize terminal equipment in the local Central Office and in a remote structure close to the end-customers. These remote structures consisted of terminal equipment mounted in bay frameworks and powered by individual-bay, embedded power systems. This study investigated the embedded power systems economics and applied typical Central Office powering architectures to the enclosures. The results indicated a common powering system is more economical than embedded systems, and increases structure circuit capacity providing the maximum benefit of the SLC Carrier technology and remote terminal structure. The economic savings and increased circuit capacity were achieved by adding a common DC power plant, designed for small applications, and replacing the individual-bay, embedded powering systems with additional terminal equipment. The power plant included a modular design facilitating the deference of power costs until the circuit growth materialized.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129242053","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":"On Linear Modeling of Switched-Mode Power-Processing Cells and its Applications","authors":"A. Kislovski","doi":"10.1109/INTLEC.1987.4794596","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794596","url":null,"abstract":"The review of the fundamental ideas on which the linear dynamic analysis of switched-mode power-processing cells is based shows that the low-frequency and the small-amplitude restrictions combined which the notion of the controlled quantity permit the establishment of a truly general linear model of these structures with time-varying topology. The model obtained comprises two dependent generators and two impedances defined by means of six characteristic coefficients. The topology of the model is invariant, and is independent of the original cell structure, operating mode and the choice of the controlled quantity. The model describes all essential low-frequency, small-amplitude properties of the original cell and can be used for general dynamic analysis of power supplies utilizing switched-mode power processing cells. The characteristic coefficients defining the model parameters can be tabulated for repeated use and thus a library of data on the dynamic behaviour of various cells can be established. Tables presenting characteristic coefficients of a selection of switched-mode power-processing cells of various structures, operating in different modes and with most popular controlled quantities, are given. The use of the tables is demonstrated using examples based on the general analysis of the switched-mode power supplies. The linear cell model synthesized by the characteristic coefficients method is compared to the linear models obtained by other methods. It is explained that the models resulting from these researches can also be used in the tables of characteristic coefficients.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115905808","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":"Rectifier Technology Development during the Last Thirty Years","authors":"T. Wolpert","doi":"10.1109/INTLEC.1987.4794527","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794527","url":null,"abstract":"This paper gives the basic review of the technology development of rectifiers for central power plants in telecommunications centres. The following rectifier technologies are described - transductor-controlled rectifiers with polycrystalline and monocrystalline valves; - thyristor-controlled rectifiers; - ferroresonant stabilizers and controlled ferroresonant devices; - switched mode direct-off-line rectifiers with bipolar and MOSFET transistors; and - high-frequency resonant-mode rectifiers with transistors and PNPN switches.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124658251","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":"Optical-Type Hydrometer for Lead-Acid Batteries and its Applications","authors":"Y. Nagai, Y. Tomokuni, T. Matsui","doi":"10.1109/INTLEC.1987.4794631","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794631","url":null,"abstract":"As the most widely used means to know the charged condition of a lead-acid battery, the method to measure the specific gravity of the electrolyte is adopted. Here we report in this paper on an optical-type sensor taking advantage of the fact that the sulfuric acid electrolyte has a certain definite refractive index in accordance with its specific gravity and the device applying such a principle. Several years ago, we had already developed a specific gravity meter based in the aforementioned principle for use to the stationary type lead-acid batteries. Said optical-type sensor is completely insulated from a electrolyte and obtains linear specific gravity values converted into at the standard temperature. It can be commonly inserted with the conventional vent plug. And various improvements have been made with regard to its reliability and precision in measuring, culminating in today's ±0.003 accuracy in performance.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122920060","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":"Safety Specifications for Equipment Supplying Energy to Telecommunication Network","authors":"Erkki Pullola","doi":"10.1109/INTLEC.1987.4794633","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794633","url":null,"abstract":"Point of view of safety authority which is responsible of the safe use of electricity in Finland, about the international safety requirements for telecommunication equipment.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123092938","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":"Diesel Alternators and Thyristor Rectifiers - Potentially Unstable Partners","authors":"M. Mack, Richard Cruise","doi":"10.1109/INTLEC.1987.4794551","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794551","url":null,"abstract":"Over the past 12 years Telecom Australia has introduced thyristor phase-controlled rectifiers in new and existing installations, but recently, a spate of instability problems has occurred between these rectifiers and diesel-alternator plant. The problem is complex and numerous theories have been tendered as a solution. Traditional methods of specifying rectifiers and generating sets would seem inadequate in this regard. Specifying a limit of alternator harmonic distortion on a linear load achieves very little when loads are predominantly phase-controlled rectifiers. A number of areas are being investigated, including the role played by rectifier harmonic filters and power factor correction components, alternator capacity verses percentage non-linear load, notching, separately-excited versus self-excited alternators and the deleterious affect of other essential loads such as fluorescent lighting. This paper discusses the above investigations with a view to developing new specifications to improve the compatibility of rectifier and alternator plant.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122733583","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":"Future Trends in DC/DC Converters for Telecommunications","authors":"Flemming Aarup","doi":"10.1109/INTLEC.1987.4794529","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794529","url":null,"abstract":"The paper shows the advantages and disadvantages of using the latest topologies in DC/DC converter designs, up to power levels of about 300 Watt. Examples will show different way of controlling feed-back by means of high reliabilty opto-couplers and magnetics. The trends in using higher switching frequencies and the relationship with conducted and radiated noise problems will be shown, along with the growing use of amorphous magnetic materials in regulated amplifier circuits. New production techniques and their effect on reliability and MTBF will be shown and discussed. The author will demonstrate design problems and their solutions in the development of a high reliability multi-output DC/DC converter to be used to supply electronics for fibreoptics. The author, Flemming Aarup, is the managing Director of Danica Supply, Smedevaenget 1-7, DK-5560 Aarup. He has a background as a design engineer of electromedical equipment over 8 years, and has specialised in the design of power supplies for the last 10 years.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125820364","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":"Telecommunications Power Systems the Operations and Maintenance Perspective","authors":"J. Coppinger","doi":"10.1109/INTLEC.1987.4794582","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794582","url":null,"abstract":"INTELEC provides a unique international forum where manufacturing industry and telecommunications operating companies (Telco's) can meet and discuss issues of mutual interest in the field of telecommunications energy. The majority of papers quite naturally present the latest technological developments from industry. Clearly there is a need also for the Telco viewpoint if we are to achieve a dialogue and harness demand pull to technological push. This paper presents the operations and maintenance viewpoint from British Telecom in its role as a supplier of telecommunications services on the one hand and as a customer of manufacturing industry on the other. It is hoped that the views expressed will further enhance industry understanding of Telco needs, to the benefit of future power systems developments.","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"199 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132654867","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":"Lead Acid Batteries for Telecommunication Requirements","authors":"D. Berndt, H. Franke","doi":"10.1109/INTLEC.1987.4794539","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794539","url":null,"abstract":"","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132831705","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":"Supervision of Flooded and Valve Regulated Sealed Lead-Acid Batteries","authors":"R. Elgh, C. Svensson","doi":"10.1109/INTLEC.1987.4794630","DOIUrl":"https://doi.org/10.1109/INTLEC.1987.4794630","url":null,"abstract":"","PeriodicalId":129305,"journal":{"name":"INTELEC '87 - The Ninth International Telecommunications Energy Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129948473","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}