Pub Date : 1990-10-21DOI: 10.1109/INTLEC.1990.171298
G. Goglia, D. Biondini, G. Mascia
The outline of a new PV (photovoltaic) storage battery charge regulator is given. The novelty of this system consists in its working on electrolyte density so that the induced current provided by the PV generator is adjusted according to the actual state of charge. This device is fitted into a new hybrid experimental PV energy power supply system for both telecommunication systems and emergency DEG (diesel engine generator), which is operated in case of low battery capacity. The device has also been used to start and stop the DEG with better results than the ones provided by the system based on threshold values of the battery voltage.<>
{"title":"Preset photovoltaic systems charge regulator based on electrolyte density measurement","authors":"G. Goglia, D. Biondini, G. Mascia","doi":"10.1109/INTLEC.1990.171298","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171298","url":null,"abstract":"The outline of a new PV (photovoltaic) storage battery charge regulator is given. The novelty of this system consists in its working on electrolyte density so that the induced current provided by the PV generator is adjusted according to the actual state of charge. This device is fitted into a new hybrid experimental PV energy power supply system for both telecommunication systems and emergency DEG (diesel engine generator), which is operated in case of low battery capacity. The device has also been used to start and stop the DEG with better results than the ones provided by the system based on threshold values of the battery voltage.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130284943","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171285
K. Akuto, T. Ogata
The structure and performance of the world's first ultra-thin sealed lead-acid batteries are described. The batteries are 0.65 mm thick, the thinnest ever achieved, and are made possible by a new electrode structure. In a conventional battery, the separator is sandwiched between the positive and negative electrodes. In the new battery structure, however, the positive electrode, electrolyte, and negative electrode are arranged on the same plane. Movement of the battery reaction sites during charge/discharge is parallel to the main surface of the electrode. Consequently, the new battery structure offers significant advantages in regard to life performance. Batteries utilizing this new structure have a long life of over 400 cycles, and good performance of the charge/discharge characteristics. In addition, a variety of different batteries can be manufactured using screen patterns. By using the techniques described above, the thickness of a sealed lead-acid battery can be reduced to less than one seventh of that of a conventional one, without performance degradation.<>
{"title":"Ultra-thin sealed lead-acid batteries","authors":"K. Akuto, T. Ogata","doi":"10.1109/INTLEC.1990.171285","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171285","url":null,"abstract":"The structure and performance of the world's first ultra-thin sealed lead-acid batteries are described. The batteries are 0.65 mm thick, the thinnest ever achieved, and are made possible by a new electrode structure. In a conventional battery, the separator is sandwiched between the positive and negative electrodes. In the new battery structure, however, the positive electrode, electrolyte, and negative electrode are arranged on the same plane. Movement of the battery reaction sites during charge/discharge is parallel to the main surface of the electrode. Consequently, the new battery structure offers significant advantages in regard to life performance. Batteries utilizing this new structure have a long life of over 400 cycles, and good performance of the charge/discharge characteristics. In addition, a variety of different batteries can be manufactured using screen patterns. By using the techniques described above, the thickness of a sealed lead-acid battery can be reduced to less than one seventh of that of a conventional one, without performance degradation.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127739657","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171254
V. Maunula, T. Keranen
A novel system designed for maintenance of stationary batteries is described. Technical specifications and functions of the system are discussed and the operating experiences gained from the use of the system at the Helsinki Telephone Company over a period of three years are described. The battery maintenance system incorporates a portable measuring and data logging unit and a program package for battery data analysis on a PC/XT and AT compatible microcomputer. A matrix or laser printer can be used for printing reports.<>
{"title":"Computerized battery log","authors":"V. Maunula, T. Keranen","doi":"10.1109/INTLEC.1990.171254","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171254","url":null,"abstract":"A novel system designed for maintenance of stationary batteries is described. Technical specifications and functions of the system are discussed and the operating experiences gained from the use of the system at the Helsinki Telephone Company over a period of three years are described. The battery maintenance system incorporates a portable measuring and data logging unit and a program package for battery data analysis on a PC/XT and AT compatible microcomputer. A matrix or laser printer can be used for printing reports.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124882945","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171223
K. Al-haddad, R. Chaffai, V. Rajagopalan
A high-performance utility-interactive series resonant inverter operating in a quasi-resonant mode is analyzed. The maximum power tracking is achieved by a linear control circuit. The inverter uses controllable turn-on and zero current turn-off COMFET switches operating in inaudible frequency range (20-100 kHz). The inverter switches operate in the soft commutation mode, no dissipative snubber is needed. The topology proposed combines the advantages of working at high frequency (less weight, small reactive filters and absence of low frequency transformer), and of using a resonant link, which makes possible the use of the well adapted zero-current turn off COMFET switches.<>
{"title":"High frequency inverter using zero current turn off COMFET switches for solar energy conversion","authors":"K. Al-haddad, R. Chaffai, V. Rajagopalan","doi":"10.1109/INTLEC.1990.171223","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171223","url":null,"abstract":"A high-performance utility-interactive series resonant inverter operating in a quasi-resonant mode is analyzed. The maximum power tracking is achieved by a linear control circuit. The inverter uses controllable turn-on and zero current turn-off COMFET switches operating in inaudible frequency range (20-100 kHz). The inverter switches operate in the soft commutation mode, no dissipative snubber is needed. The topology proposed combines the advantages of working at high frequency (less weight, small reactive filters and absence of low frequency transformer), and of using a resonant link, which makes possible the use of the well adapted zero-current turn off COMFET switches.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121604515","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171267
A. Geri, G. Veca
A model is described for the evaluation of the transient behavior of a lightning protection system during the draining to earth of a lightning current. The dynamic analysis is executed taking into account the possible nonlinear ionization phenomena. The model is based on the evaluation of the electromotive forces induced in open square turns by spatially distributed lightning current through the protection system. The user-friendly model implementation simplifies the preliminary analysis for the minimization of the EMI (electromagnetic interference) risk during a lightning stroke.<>
{"title":"Representation and analysis of the equivalent lightning protection system network for nonlinear problems in the electromagnetic interference control","authors":"A. Geri, G. Veca","doi":"10.1109/INTLEC.1990.171267","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171267","url":null,"abstract":"A model is described for the evaluation of the transient behavior of a lightning protection system during the draining to earth of a lightning current. The dynamic analysis is executed taking into account the possible nonlinear ionization phenomena. The model is based on the evaluation of the electromotive forces induced in open square turns by spatially distributed lightning current through the protection system. The user-friendly model implementation simplifies the preliminary analysis for the minimization of the EMI (electromagnetic interference) risk during a lightning stroke.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126418040","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171251
W. Brecht
An experimental apparatus and technique were developed to demonstrate the impact of silica on oxygen transport rate. The first series of quantitative data developed using the described apparatus is reported. The enhancement in the rate of oxygen transfer between positive and negative electrodes as a function of type and amount of silica introduced into the system is discussed in relation to the Tafel diagram and the rate of oxygen recombination in the regime of float operation. A spinning disk electrode is utilized for making polarization and current measurements. A modification to the standard ECC cyclic voltammetry technique allows depolarization of the negative electrode by oxygen transfer to be measured directly and rapidly as the rate of oxygen transport from the positive electrode is increased by addition of various forms and quantities of silica into the electrolyte.<>
{"title":"An investigation of the effect of silica addition on the rate of oxygen transfer in lead-acid batteries","authors":"W. Brecht","doi":"10.1109/INTLEC.1990.171251","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171251","url":null,"abstract":"An experimental apparatus and technique were developed to demonstrate the impact of silica on oxygen transport rate. The first series of quantitative data developed using the described apparatus is reported. The enhancement in the rate of oxygen transfer between positive and negative electrodes as a function of type and amount of silica introduced into the system is discussed in relation to the Tafel diagram and the rate of oxygen recombination in the regime of float operation. A spinning disk electrode is utilized for making polarization and current measurements. A modification to the standard ECC cyclic voltammetry technique allows depolarization of the negative electrode by oxygen transfer to be measured directly and rapidly as the rate of oxygen transport from the positive electrode is increased by addition of various forms and quantities of silica into the electrolyte.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125171306","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171216
R. Ireland
Summary form only given. The impact on Pacific Bell of the October 1989 San Francisco Bay earthquake is addressed. Due to emergency power backup, telephone services were perceived as reliable. The performance of digital loop carrier and remote electronics under critical conditions is reported, and the lessons learned are briefly discussed.<>
{"title":"Learnings and challenges of the Northern California earthquake (telephone services)","authors":"R. Ireland","doi":"10.1109/INTLEC.1990.171216","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171216","url":null,"abstract":"Summary form only given. The impact on Pacific Bell of the October 1989 San Francisco Bay earthquake is addressed. Due to emergency power backup, telephone services were perceived as reliable. The performance of digital loop carrier and remote electronics under critical conditions is reported, and the lessons learned are briefly discussed.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129487849","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171274
W. Rutledge
The process and criteria for the selection of an intelligent power monitor and control system at Pacific Bell are discussed. A three-year study resulted in a two-year trial of two different systems. Requirements for intelligent power are formulated, and the two systems and their specific features are outlined. The greatest difference between the two trial systems is that the vendor A system allows complete data monitoring and control through the local telephone access port in the event of a dedicated facility or host computer failure. Thus the unanswered alarm escalation features will still function even to the point of beeper call if the facility or host computer system is down. The vendor B system, at present, only allows network access (both in and out) to any office under surveillance through the host computer. Thus either a computer or facility failure would totally isolate the intelligent power plant interface and any assigned satellites.<>
{"title":"Trial application of intelligent power at Pacific Bell","authors":"W. Rutledge","doi":"10.1109/INTLEC.1990.171274","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171274","url":null,"abstract":"The process and criteria for the selection of an intelligent power monitor and control system at Pacific Bell are discussed. A three-year study resulted in a two-year trial of two different systems. Requirements for intelligent power are formulated, and the two systems and their specific features are outlined. The greatest difference between the two trial systems is that the vendor A system allows complete data monitoring and control through the local telephone access port in the event of a dedicated facility or host computer failure. Thus the unanswered alarm escalation features will still function even to the point of beeper call if the facility or host computer system is down. The vendor B system, at present, only allows network access (both in and out) to any office under surveillance through the host computer. Thus either a computer or facility failure would totally isolate the intelligent power plant interface and any assigned satellites.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132094315","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171308
J. McKay
To assess the effectiveness of air-to-air heat exchangers in reducing peak temperature rise in outdoor telephone equipment cabinets, a series of tests was conducted during the summer of 1989 at the Chester thermal test facility. The tests demonstrated that an average 10 degrees F or better reduction in peak internal air temperature within outdoor cabinets could be achieved using a simple air-to-air heat exchanger. This drop was measured in a 50 ft/sup 3/ cabinet with internal heat loads of 680 and 920 watts, and was in addition to any reduction obtained through use of internal air circulating fans. About the same peak internal air temperature was obtained for the 920 watt load without the heat exchanger operating. The author describes the test procedure and results.<>
{"title":"Use of an air-to-air heat exchanger to reduce peak temperatures in outdoor cabinets","authors":"J. McKay","doi":"10.1109/INTLEC.1990.171308","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171308","url":null,"abstract":"To assess the effectiveness of air-to-air heat exchangers in reducing peak temperature rise in outdoor telephone equipment cabinets, a series of tests was conducted during the summer of 1989 at the Chester thermal test facility. The tests demonstrated that an average 10 degrees F or better reduction in peak internal air temperature within outdoor cabinets could be achieved using a simple air-to-air heat exchanger. This drop was measured in a 50 ft/sup 3/ cabinet with internal heat loads of 680 and 920 watts, and was in addition to any reduction obtained through use of internal air circulating fans. About the same peak internal air temperature was obtained for the 920 watt load without the heat exchanger operating. The author describes the test procedure and results.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132643545","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 : 1990-10-21DOI: 10.1109/INTLEC.1990.171249
H. Hayama, M. Nakao, M. Sanbe
A high efficiency air conditioning system has been developed for application to telecommunications equipment rooms. The design specifically addresses the cooling characteristics of natural cooling equipment and the uneven distribution of heat in equipment rooms. The system can also flexibly accommodate different equipment layouts in the room. Excellent efficiency of natural cooling equipment is achieved through the use of chambers under a raised floor for air supply and above a suspended ceiling for air return to the cooling unit. A method of calculating the air supply/return distribution is presented to optimize the airflow distribution. It is shown that rearranging the perforated raised floor panels is a practical and economical way of delivering the exact required air volume to the room. Installing the system in some actual equipment rooms, measurements were taken of the room temperature distribution and performance of the cooling system. Satisfactory results were obtained for the volume and temperature distributions. It is further found that the volume of air circulated by the cooling unit fans can be substantially reduced compared to a conventional cooling system.<>
{"title":"Airflow distribution in telecommunications equipment rooms","authors":"H. Hayama, M. Nakao, M. Sanbe","doi":"10.1109/INTLEC.1990.171249","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171249","url":null,"abstract":"A high efficiency air conditioning system has been developed for application to telecommunications equipment rooms. The design specifically addresses the cooling characteristics of natural cooling equipment and the uneven distribution of heat in equipment rooms. The system can also flexibly accommodate different equipment layouts in the room. Excellent efficiency of natural cooling equipment is achieved through the use of chambers under a raised floor for air supply and above a suspended ceiling for air return to the cooling unit. A method of calculating the air supply/return distribution is presented to optimize the airflow distribution. It is shown that rearranging the perforated raised floor panels is a practical and economical way of delivering the exact required air volume to the room. Installing the system in some actual equipment rooms, measurements were taken of the room temperature distribution and performance of the cooling system. Satisfactory results were obtained for the volume and temperature distributions. It is further found that the volume of air circulated by the cooling unit fans can be substantially reduced compared to a conventional cooling system.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114068462","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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