Pub Date : 1994-04-11DOI: 10.1109/TELESC.1994.4794320
J. Horzepa, Dan McMenemin, W. Cantor, T. Cantor
Competitive pressures are forcing Operating Telephone Companies to look for opportunities that will improve fmancial performance by growing revenues and earnings and reducing operating and maintenance expenses. There is also pressure from regulatory agencies and consumer groups to improve the reliability of service and to minimize outages due to failures of equipment or utility power. The paper will discuss the role that Battery Performance testing can play in providing input for making decisions on reducing or delaying capital investments while assuring a high level of reliability in reusing existing batteries.
{"title":"Battery Evaluation and Certification Testing - Case Studies","authors":"J. Horzepa, Dan McMenemin, W. Cantor, T. Cantor","doi":"10.1109/TELESC.1994.4794320","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794320","url":null,"abstract":"Competitive pressures are forcing Operating Telephone Companies to look for opportunities that will improve fmancial performance by growing revenues and earnings and reducing operating and maintenance expenses. There is also pressure from regulatory agencies and consumer groups to improve the reliability of service and to minimize outages due to failures of equipment or utility power. The paper will discuss the role that Battery Performance testing can play in providing input for making decisions on reducing or delaying capital investments while assuring a high level of reliability in reusing existing batteries.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131415794","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794361
H. Yonemori, H. Nagura, M. Nakaoka
This paper presents a newly-developed high-performance 3¿CVCF power conversion conditioner incorporating a new Quasi-Resonant DC Link (QRDCL) single-phase inverter with PWM function and high-frequency AC transformer linked cycloconverter topology. The operating characteristics of a proposed QRDCLI are discussed on the basis of computer-aided simulating results. In order to achieve a significant improvement in high performance and quick control response, the specially-designed voltage Pulse Distributed vector control Modulation (Modified PDM) scheme is introduced through employing DSP software-based control implementation. In addition, this instantaneous voltage vector controlled 3¿CVCF power conditioning and processing system suitable for a low EMI, high-power density UPS is evaluated and discussed for linear and non-linear electrical loads under the conditions of large load variations from a practical point of view.
{"title":"Latest Three-Phase CVCF Sinwave Power Conditioner with New Quasi-Resonant ZVS DC and High-Frequency AC Link for Telephone Power Supply Systems","authors":"H. Yonemori, H. Nagura, M. Nakaoka","doi":"10.1109/TELESC.1994.4794361","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794361","url":null,"abstract":"This paper presents a newly-developed high-performance 3¿CVCF power conversion conditioner incorporating a new Quasi-Resonant DC Link (QRDCL) single-phase inverter with PWM function and high-frequency AC transformer linked cycloconverter topology. The operating characteristics of a proposed QRDCLI are discussed on the basis of computer-aided simulating results. In order to achieve a significant improvement in high performance and quick control response, the specially-designed voltage Pulse Distributed vector control Modulation (Modified PDM) scheme is introduced through employing DSP software-based control implementation. In addition, this instantaneous voltage vector controlled 3¿CVCF power conditioning and processing system suitable for a low EMI, high-power density UPS is evaluated and discussed for linear and non-linear electrical loads under the conditions of large load variations from a practical point of view.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127599569","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794312
G. Gerdai
The Hungarian Telecom Company wants to invest a lot into the new telephone exchanges in the future. Of course, the new exchanges require also new power systems. It is very important to assure the conditions of the high-quality power supplies. The technical requirements should be worked out, new types of the equipment should be examined and the right maintenance should be organised.
{"title":"Development of the power supplies at the Hungarian Telecom","authors":"G. Gerdai","doi":"10.1109/TELESC.1994.4794312","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794312","url":null,"abstract":"The Hungarian Telecom Company wants to invest a lot into the new telephone exchanges in the future. Of course, the new exchanges require also new power systems. It is very important to assure the conditions of the high-quality power supplies. The technical requirements should be worked out, new types of the equipment should be examined and the right maintenance should be organised.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134406565","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794366
I. Miyazaki, K. Harada, M. Jinno
The purpose of this work is to realize a simple power interface circuit between an alternative energy system and the utility grid that has the intrinsic property of protective isolation during the course of the line fault. We will propose a power interface using a biased saturable transformer. This circuit has the intrinsic properties not only of isolation but also of spontaneous disconnection in the course of the line fault. The quantity and the direction of the power from the dc source to the utility grid are controlled only by the phase lead angle of the inverter. It is possible to use this power interface in the high frequency linked equipment with its own properties.
{"title":"A HF-Linked Power Interface using a Biased Saturable Transformer","authors":"I. Miyazaki, K. Harada, M. Jinno","doi":"10.1109/TELESC.1994.4794366","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794366","url":null,"abstract":"The purpose of this work is to realize a simple power interface circuit between an alternative energy system and the utility grid that has the intrinsic property of protective isolation during the course of the line fault. We will propose a power interface using a biased saturable transformer. This circuit has the intrinsic properties not only of isolation but also of spontaneous disconnection in the course of the line fault. The quantity and the direction of the power from the dc source to the utility grid are controlled only by the phase lead angle of the inverter. It is possible to use this power interface in the high frequency linked equipment with its own properties.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115218997","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794377
G. Papazov, I. Nikolov, D. Pavlov, T. Vitanov
The main reactions involved in thie clharge process of positive and negative lead-acid battery plates are associated with electrochemical decomposition of water. TIo avoid fallinig downI of the electrolyte level, the battery must be regularly topped up withi water, i.e. it requir-es miaintenance In priniciple, two methlods hiave beeni developed to reduce water loss durinig battery operation. Thle first inivolves inicreasing the overvoltage of hiydrogein and oxygen evolution by the use of special alloys, and limiliting the clharge voltage to below the voltage of water decompositioni. The second approach to imasiilnteniance-lfr-ee operation is to enicoLur-age tle recombiniationi of the hydrogen anti oxygeni released in the ceML. This can be achieved tlhrough: (a) an oxygen cycle, whereby the oxygeni released on the positive plate is reduced on the negative one; (b) recombinatiotn of the released gases to water on the catalytic plug; (c) oxygen reduction and hydrogen oxidation on the partially-inimiersed catalytic electrodes. It was established in the 1970's [1,21 that tunigsten carbide (WC) hiad good catalytic activity towards the 1-12 reaction in1H2SO4 electrolyte. Trhe aims of the present study are to inivestigate the catalytic activity of WC towai-ds hydrogen and oxygen released during lead-acid lbaittery operation, and to develop a lead-acid battery with partially immnersed WC clectrodes.
{"title":"Application of WC Electrodes in Stationary Batteries","authors":"G. Papazov, I. Nikolov, D. Pavlov, T. Vitanov","doi":"10.1109/TELESC.1994.4794377","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794377","url":null,"abstract":"The main reactions involved in thie clharge process of positive and negative lead-acid battery plates are associated with electrochemical decomposition of water. TIo avoid fallinig downI of the electrolyte level, the battery must be regularly topped up withi water, i.e. it requir-es miaintenance In priniciple, two methlods hiave beeni developed to reduce water loss durinig battery operation. Thle first inivolves inicreasing the overvoltage of hiydrogein and oxygen evolution by the use of special alloys, and limiliting the clharge voltage to below the voltage of water decompositioni. The second approach to imasiilnteniance-lfr-ee operation is to enicoLur-age tle recombiniationi of the hydrogen anti oxygeni released in the ceML. This can be achieved tlhrough: (a) an oxygen cycle, whereby the oxygeni released on the positive plate is reduced on the negative one; (b) recombinatiotn of the released gases to water on the catalytic plug; (c) oxygen reduction and hydrogen oxidation on the partially-inimiersed catalytic electrodes. It was established in the 1970's [1,21 that tunigsten carbide (WC) hiad good catalytic activity towards the 1-12 reaction in1H2SO4 electrolyte. Trhe aims of the present study are to inivestigate the catalytic activity of WC towai-ds hydrogen and oxygen released during lead-acid lbaittery operation, and to develop a lead-acid battery with partially immnersed WC clectrodes.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114371772","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794319
U. Teutsch
Valve-regulated lead-acid batteries are often used in uninte-rruptible power supplies. In these applications, the battery is continuously charged at low voltage to avoid gradual self (dischlarge. During float charging, SCVCIeral rCeqlir-emients have to be imiet: * In each cell positive and negative electriodes should be polarized sufficiently to maintain full state of charge. . The rates of water decomposition and grid corrosion shiould be as low as possible to ensure long service life. . Scattering of cell voltages in a battery string shlold be small, to allow a relatively low float voltage and to avoid non-unifor-mii ageing of cells. In the scope of an investigationi of factors relevant to thsce irequireIcints. a ma(tlhemiiatical model for float charging of lead-acid batteries has been developed, describing cffects otf float conditions and kinetic cell paramleter s on electrode potentials and electrode reaction rates.
{"title":"A Mathematical Model for Float Operation of Valve-Regulated Lead-Acid Batteries","authors":"U. Teutsch","doi":"10.1109/TELESC.1994.4794319","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794319","url":null,"abstract":"Valve-regulated lead-acid batteries are often used in uninte-rruptible power supplies. In these applications, the battery is continuously charged at low voltage to avoid gradual self (dischlarge. During float charging, SCVCIeral rCeqlir-emients have to be imiet: * In each cell positive and negative electriodes should be polarized sufficiently to maintain full state of charge. . The rates of water decomposition and grid corrosion shiould be as low as possible to ensure long service life. . Scattering of cell voltages in a battery string shlold be small, to allow a relatively low float voltage and to avoid non-unifor-mii ageing of cells. In the scope of an investigationi of factors relevant to thsce irequireIcints. a ma(tlhemiiatical model for float charging of lead-acid batteries has been developed, describing cffects otf float conditions and kinetic cell paramleter s on electrode potentials and electrode reaction rates.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116748770","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794367
K. Yurugi, H. Yonemori, M. Nakaoka
This paper presents the state-of-the-art Discrete Pulse Modulated(DPM) three-phase AC/DC power converter with an Active-Voltage Clamped Resonant DC Link (ACRDCL). Its DSP-based digital control strategy to realize a unity power factor correction and sinewave line current shaping is proposed. The operating characteristics are illustrated using simulational results and experimental data. In addition, the biderectional double power conversion circuit with a single stage of ACRDCL is demonstrated as an extended concept of the switched mode DPM rectifier treated here.
{"title":"Three Phase Resonant DC Link PDM Active Converter with Unity Power Factor and Sinewave Current Shaping Functions","authors":"K. Yurugi, H. Yonemori, M. Nakaoka","doi":"10.1109/TELESC.1994.4794367","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794367","url":null,"abstract":"This paper presents the state-of-the-art Discrete Pulse Modulated(DPM) three-phase AC/DC power converter with an Active-Voltage Clamped Resonant DC Link (ACRDCL). Its DSP-based digital control strategy to realize a unity power factor correction and sinewave line current shaping is proposed. The operating characteristics are illustrated using simulational results and experimental data. In addition, the biderectional double power conversion circuit with a single stage of ACRDCL is demonstrated as an extended concept of the switched mode DPM rectifier treated here.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"47 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117335228","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794336
J. Schultze, J. Bodet, R. Bonnaterre
The portable telecommunications market (cellular phones, etc) represents a major outlet for batteries in the next five years. The compactness, light weight, extended autonomy and low price required for mass market telephone sets are also needed for the batteries. To meet these demands, Saft is developing and manufacturing batteries with a range of different technologies (Nickel-Cadmium, Nickel- Metal Hydride, Lithium-Ion) offering a variety of performance/price ratios. Saft's new batteries are presented and their test performances for a GSM-type application are described. When optimizing battery performance and ensuring user safety, these multiple technologies entail system constraints on chargers, charging methods etc. Saft has therefore custom-designed a charger (presented here) for portable telecommunications applications, which accepts two different battery technologies.
{"title":"Recent Improvements and Future Developments in Portable Batteries and their Associated Electronics","authors":"J. Schultze, J. Bodet, R. Bonnaterre","doi":"10.1109/TELESC.1994.4794336","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794336","url":null,"abstract":"The portable telecommunications market (cellular phones, etc) represents a major outlet for batteries in the next five years. The compactness, light weight, extended autonomy and low price required for mass market telephone sets are also needed for the batteries. To meet these demands, Saft is developing and manufacturing batteries with a range of different technologies (Nickel-Cadmium, Nickel- Metal Hydride, Lithium-Ion) offering a variety of performance/price ratios. Saft's new batteries are presented and their test performances for a GSM-type application are described. When optimizing battery performance and ensuring user safety, these multiple technologies entail system constraints on chargers, charging methods etc. Saft has therefore custom-designed a charger (presented here) for portable telecommunications applications, which accepts two different battery technologies.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116108214","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794356
P. Schmidt
Today there are three main possibilities for further energy savings in the cooling of digital switching rooms of the Telekom, using the existing unit technology: - Change to constant temperature difference control The savings potential of this measure mainly depends on the existing partial load condition of the individual installation. The magnitude cannot be indicated in general, but as an average it should be at least 30 to 35%. - Accurate consideration of external pressure losses The average values of all analyzed units in figure 3 shows an additional energy consumption of 8%, compared to the specification. Careful project engineering, especially for new buildings, should permit even lower external pressure losses than specified by the Muster-Leistungsverzeichnis der Deutschen Bundespost [1]. - Return temperature of 36°C throughout the year, eventually 40°C This operating mode can be implemented by simple modification of the DDC programs. It lowers the annual energy consumption by 20%, eventually even 45%. Summing up these possibilities, an overall reduction of the energy consumption of at least 50 to 60% should be possible, whereby measures 1 and 3 can be implemented on existing systems without excessive expense.
目前，利用现有的机组技术，在电信数字交换室的冷却方面有三种主要的节能可能性:-改为恒温温差控制。这种措施的节能潜力主要取决于单个装置的现有部分负载情况。震级不能一般地表示，但作为一个平均值，它应该至少是30至35%。-准确考虑外部压力损失图3中所有分析单元的平均值显示，与规格相比，额外的能耗为8%。仔细的项目工程，特别是对于新建筑，应允许比德国联邦邮政(Muster-Leistungsverzeichnis der Deutschen Bundespost)规定的更低的外部压力损失[1]。—全年返回温度36℃，最终返回温度40℃。通过简单修改DDC程序，即可实现此工作模式。它能将年能耗降低20%，最终甚至达到45%。综上所述，总体上至少可以减少50%至60%的能源消耗，因此措施1和3可以在现有系统上实施，而不会产生过多的费用。
{"title":"Future Possibilities to Save Energy by Cooling Equipment in Switching Rooms of Central Offices","authors":"P. Schmidt","doi":"10.1109/TELESC.1994.4794356","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794356","url":null,"abstract":"Today there are three main possibilities for further energy savings in the cooling of digital switching rooms of the Telekom, using the existing unit technology: - Change to constant temperature difference control The savings potential of this measure mainly depends on the existing partial load condition of the individual installation. The magnitude cannot be indicated in general, but as an average it should be at least 30 to 35%. - Accurate consideration of external pressure losses The average values of all analyzed units in figure 3 shows an additional energy consumption of 8%, compared to the specification. Careful project engineering, especially for new buildings, should permit even lower external pressure losses than specified by the Muster-Leistungsverzeichnis der Deutschen Bundespost [1]. - Return temperature of 36°C throughout the year, eventually 40°C This operating mode can be implemented by simple modification of the DDC programs. It lowers the annual energy consumption by 20%, eventually even 45%. Summing up these possibilities, an overall reduction of the energy consumption of at least 50 to 60% should be possible, whereby measures 1 and 3 can be implemented on existing systems without excessive expense.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128870765","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 : 1994-04-11DOI: 10.1109/TELESC.1994.4794368
Ulrich Vollert
A problem ofteni encountered in setting up radio relay and fibre optic transnmission links is the lack of a commercial power supply network to power the repeater staions. In such situations it is necessary to provide a self-contained power supply adapted to conditions in the particular country. For stations with a high power requirement it is usual to employ conventional systems, i.e. dual or triple diesel power plants with rectifiers and batteries. For stations wlhere access is difficult, e.g. in mountainous or desert regions, or for low-power stations, however, increasing use is being made of solar and wind energy. <1> Fig 1 Power Supply systems utilizing exlusively wind and/or solar energy can be set up in many parts of the world with excellent overall cost-effectiveness. Especially a combination of the two primary energy sources depending on the right power requirement and geographical location has proven advantageous. For many years Siemens has been supplying installations of this kind for powering communication systems.
{"title":"Solar and Wind Power for Comunications Systems","authors":"Ulrich Vollert","doi":"10.1109/TELESC.1994.4794368","DOIUrl":"https://doi.org/10.1109/TELESC.1994.4794368","url":null,"abstract":"A problem ofteni encountered in setting up radio relay and fibre optic transnmission links is the lack of a commercial power supply network to power the repeater staions. In such situations it is necessary to provide a self-contained power supply adapted to conditions in the particular country. For stations with a high power requirement it is usual to employ conventional systems, i.e. dual or triple diesel power plants with rectifiers and batteries. For stations wlhere access is difficult, e.g. in mountainous or desert regions, or for low-power stations, however, increasing use is being made of solar and wind energy. <1> Fig 1 Power Supply systems utilizing exlusively wind and/or solar energy can be set up in many parts of the world with excellent overall cost-effectiveness. Especially a combination of the two primary energy sources depending on the right power requirement and geographical location has proven advantageous. For many years Siemens has been supplying installations of this kind for powering communication systems.","PeriodicalId":178715,"journal":{"name":"TELESCON '94 - The First International Telecommunications Energy Special Conference","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124133381","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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