{"title":"Active Clamp Converter with Full Resonant Switching","authors":"M. E. Jacobs","doi":"10.1109/INTLEC.2006.251605","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251605","url":null,"abstract":"The active clamp DC-DC converter topology efficiently resets the flux in the power transformer with an active switch and a clamp capacitor and provides low peak-inverse voltage for the output rectifiers over a wide operating range of input voltage. But like other isolated power conversion topologies, this topology loses zero-voltage switching (ZVS) for one of the switching transitions, requiring a switch to close across a low impedance with significant voltage. The loss of ZVS is analyzed, and it is shown that including a small inductor in series with the primary winding of the transformer and two clamping diodes can restore ZVS at any load current. A balancing resistor coupled to the clamp capacitor recovers nearly all the recycled energy from the added inductor","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113978751","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":"Do You Want to Know More? RFID Tags on Stationary Batteries","authors":"H. Giess","doi":"10.1109/INTLEC.2006.251600","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251600","url":null,"abstract":"Stationary lead acid batteries are essential building blocks for reliable emergency power back-up solutions and the traceability of key manufacturing steps and properties over their life cycle enhances their reliability. The actual traceability is achieved with a lot of paper work consisting of spreadsheet lists, semiautomatic data banks, barcode labels, shipping papers and so on. IEC TC21 proposes to raise a standard for the information content of RFID tags applied to stationary lead acid batteries. The areas of benefit of such an identification method in battery production, logistics, battery use and recycling are outlined. This standardization would not intervene in the \"electronics\" of the RFID but assure with high priority that battery environment and battery user relevant data are taken in account, stored and retrieved with ease. An example of such an information string is shown","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122388781","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":"Using Energy-Efficient Technologies to Lower Operational Costs in High-Density Environment","authors":"P. Gross, K. L. Godrich","doi":"10.1109/INTLEC.2006.251651","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251651","url":null,"abstract":"High-density server facilities have quickly become a widespread reality. Not only are they adding nearly 1 GW to the US economy load, but many of these major data centers are using this increase in power in a way that exceeds all market expectations. Past predictions for high-density servers racks in the year 2006 showed loads in the neighborhood of 8 KW, but today's reality shows it is in the magnitude of 300% higher-and in some case even more, racks of 35 KW are installed and commissioned. Why are we so far ahead of the forecast for needed energy? Power-hungry processors and super-charged servers","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127424073","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}
T. Iino, S. Kobayashi, H. Kobayashi, K. Yamada, T. Yachi
{"title":"Reducing Cost and Decreasing CO2 Emission Using a Shared-Distribution Fuel Cell System","authors":"T. Iino, S. Kobayashi, H. Kobayashi, K. Yamada, T. Yachi","doi":"10.1109/INTLEC.2006.251658","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251658","url":null,"abstract":"We studied the characteristics of a shared-distribution fuel cell system that supplied a community center and several houses. The system was confirmed to be effective. Compared to costs estimated before the proposed system was installed, this is projected to become economically viable after 9 years with low CO2 from the first year","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127748977","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":"Benchmarking Hydrogen Fuel Cell as an Alternative Back-Up Power for the Telecommunications Industry","authors":"D.B. Canavan, J. Dogterom, J. McDougall","doi":"10.1109/INTLEC.2006.251668","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251668","url":null,"abstract":"In our ever evolving and environmentally conscious society, we are constantly challenged to investigate alternative back-up power solutions. In the telecommunications industry, the loss of AC power cannot be allowed to affect continuous quality of service {QOS} of the DC power required to maintain essential services as provided by a telecommunications central Office. This paper will outline research and development activities accomplished to date, in progress test trial activities and what steps are required to determine long-term viability for a turnkey solution","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129438849","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":"Suitability of Fuel Cell Technology for Electricity Utility Standby Power Applications","authors":"T. Jacobs, J. Beukes","doi":"10.1109/INTLEC.2006.251669","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251669","url":null,"abstract":"This paper provides an overview of fuel cell technology in terms of its history, operation, applications and the benefits of the proton exchange membrane fuel cell versus vented lead acid batteries. Life cycle costing comparisons between vented lead acid batteries and proton exchange membrane fuel cells indicate definite benefits and showed that lower power proton exchange membrane fuel cells can compete as alternative energy storage devices in utility telecommunication sites. The criteria used to determine the suitability of an energy storage technology at a site is discussed. A section of the paper is devoted to discuss the operation of a proton exchange membrane fuel cell which is installed at a telecommunication repeater site. The integration of the fuel cell with existing DC supplies at the site, as well as preliminary test and performance results of this proton exchange membrane fuel cell installation are discussed","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128396072","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":"Considerations For High Reliability Energy Sources For Nigeria Telecommunication Limited","authors":"S.B. Orokunle, J. Gropper","doi":"10.1109/INTLEC.2006.251586","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251586","url":null,"abstract":"Nigerian Telecommunication Ltd NITEL is the first national carrier in Nigeria, and is one of the two companies licensed to carry out the telecommunication carrier business in the country. Power generation within the company's networks has remained for decades a determining factor in the evaluation of the reliability of the services provided. Hence, discussed in this paper are the migration processes with specific real-life experience on the installed power plants towards achieving high power system availability","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128282744","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":"A New Tool for Evaluating and Designing the Thermal Environment in Telecom Central Offices","authors":"M. Herrlin","doi":"10.1109/INTLEC.2006.251602","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251602","url":null,"abstract":"Telecom central offices need a metric for evaluating and designing the thermal environment to ensure effective equipment cooling without excessive energy usage. This paper presents such a metric: the rack cooling index (RCI). Although the equipment intake temperatures provide a picture of the environment, there is no yardstick for interpreting the data. The RCI has the capacity to change this situation; the index is a metric of compliance with (industry) temperature specifications, where 100% means that the equipment is ideally cooled. More importantly, it allows standardized and unbiased comparisons between different thermal environments. Ultimately, the cost of controlling the thermal conditions needs to be understood. Therefore, a cost metric for cooling the equipment room is reviewed. By incorporating the RCI and cost functions in the design process, it can be shown that a design not only improves the environment but also saves energy. The RCI is currently used to evaluate various cooling solutions as well as develop telecom standards for optimal thermal design of equipment rooms. Other applications include real-time monitoring and design specifications. It has the capacity to support non-technical decision makers since interpreting the index does not require an in-depth understanding of its definition. A design with an RCI of 95% is obviously better than one with 85%","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122646943","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":"A Novel Soft-Switching Circuit for an AC-DC Converter with a Four-Winding Reactor","authors":"R. Araki, O. Matsuo, H. Ota, M. Tuji, H. Matsuo","doi":"10.1109/INTLEC.2006.251627","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251627","url":null,"abstract":"A novel soft-switching circuit for an AC-DC converter with a four-winding reactor is presented. This AC-DC converter has high efficiency and satisfies the IEC61000-3-2 class D regulation over a wide range of input voltage, for example from 80 to 288 V. The soft-switching circuit reduces the switching power loss and performs power regeneration. As a result, high power efficiency is achieved. The design criteria for the regeneration winding can be further refined for improved performance","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117164013","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}
Teng Liu, Ziying Zhou, Aiming Xiong, J. Zeng, Jianping Ying
{"title":"A Novel Precise Design Method for LLC Series Resonant Converter","authors":"Teng Liu, Ziying Zhou, Aiming Xiong, J. Zeng, Jianping Ying","doi":"10.1109/INTLEC.2006.251606","DOIUrl":"https://doi.org/10.1109/INTLEC.2006.251606","url":null,"abstract":"In this paper, a novel precise analysis method based on time domain analysis for LLC series resonant converter is proposed and a clear design guide line is given. Because LLC resonant converter has simple structure, high efficiency and high switching frequency capability, it is widely used nowadays. To achieve an optimized design and propose a clear design guide line, understanding its DC gain characteristic and parameters effect on efficiency is very important. Traditional analysis method based on fundamental-harmonic approximation can not give accurate results. Finally, following proposed design guide line, a prototype of MHz LLC series resonant converter with 96% efficiency has been built and tested. Experimental results testified the analysis method and proposed design guide line","PeriodicalId":356699,"journal":{"name":"INTELEC 06 - Twenty-Eighth International Telecommunications Energy Conference","volume":"204 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123378057","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}