{"title":"Conversion of constant current to constant voltage by high-frequency resonant converter","authors":"T. Ninomiya, T. Higashi, K. Harada","doi":"10.1109/INTLEC.1988.22353","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22353","url":null,"abstract":"A high-frequency resonant converter with constant-current input is investigated analytically and experimentally. This converter can step up the input current and convert it into the constant voltage which is used in ordinary electronic equipment. It is useful for supplying electronic equipment which is located far from the power source and is required to be remotely supplied with a low-voltage and high-current electric power. The static characteristics of this voltage-mode resonant converter are analyzed, and the dynamic characteristics and the high-frequency operation in the megahertz range are examined experimentally.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115171855","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}
K. Yotsumoto, S. Muroyama, S. Matsumura, H. Watanabe
{"title":"Design for a highly efficient distributed power supply system based on reliability analysis","authors":"K. Yotsumoto, S. Muroyama, S. Matsumura, H. Watanabe","doi":"10.1109/INTLEC.1988.22406","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22406","url":null,"abstract":"A distributed power supply system with highly efficient characteristics is being developed to replace conventional centralized power systems. In this system, as in conventional power systems, a standby energy system composed of batteries and engine-generator sets is used as a back-up system for the commercial power lines. However, the distributed power system, except for the engine-generator set, is installed in the telecommunications room. Thus, the floor load limitation is an important design factor. Reliability analyses show that the distributed power system should be designed using a fully duplicated engine-generator set; with battery reserve time reduced to one-sixth that of conventional centralized power systems; and with transfer switch unavailability designed to be less than 5*10/sup -7/.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129530158","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":"Telephone line circuit DC-to-DC converter","authors":"D. Gradl, J. Krueger, S. Henning","doi":"10.1109/INTLEC.1988.22326","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22326","url":null,"abstract":"A unique, low-power, DC-to-DC switching converter has been developed to provided DC power for analog telephone lines. The converter uses a flyback configuration with a nonlinear element in one of two separate feedback loops. The feedback provides a dual mode of operation with constant voltage output for low-load currents and limited power output for high-load currents. This allows a simple, versatile circuit configuration that is well suited to telephone-line-feed applications. Its output characteristics cannot be reproduced with conventional linear techniques or switching converter techniques. The authors provide background information on the design of the converter and describe the operation of the converter at the functional block level. They describe the overall circuit features and characteristics of the line-feed application as well as circuit implementation and practical considerations. Finally, laboratory test results are presented.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115545175","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}
K. Harada, Y. Ji, Y. Katayama, C.J. Chen, T. Nakamizo
{"title":"Stability improvement of constant voltage transformer for triport UPS system","authors":"K. Harada, Y. Ji, Y. Katayama, C.J. Chen, T. Nakamizo","doi":"10.1109/INTLEC.1988.22404","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22404","url":null,"abstract":"A novel method for improving the stability of the AVR (automatic voltage regulator) constant voltage transformer for triport UPS (uninterruptible power supply) systems is introduced. An active filter with an operational amplifier as the feedback element for controlling the AVR is shown to reduce the system instability; this device is more compact and economical than the alternative magnetic feedback amplifier. Experimental and simulation results demonstrate the effectiveness of active filter feedback of a higher order for suppressing the instability.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116539765","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":"The effect of solar radiation and wind speed on air temperature rise in outdoor cabinets containing telephone equipment","authors":"J. McKay","doi":"10.1109/INTLEC.1988.22363","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22363","url":null,"abstract":"A series of tests is being conducted to explore various methods for economically controlling the temperature within small metal cabinets housing telephone equipment. Initial tests focus on measurement of the temperature rise in unventilated cabinets as a function of internal heat load, outdoor ambient conditions and the use of internal air circulating fans. An AT&T Community Service Cabinet, Type 80-C, was used as the test vehicle in these tests. The author reports the results from the initial test series. Among other results, it is shown that internal heat generated within the cabinet is more important than solar radiation in the air temperature rise.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126540143","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":"Reliability and availability performance as a tool to optimize power systems","authors":"T. Suntio, K. White","doi":"10.1109/INTLEC.1988.22324","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22324","url":null,"abstract":"The authors describe by means of a case study how the reliability and availability performance can be utilized to obtain the optimal solution for uninterruptible power supplies (UPS) from the power systems user's point of view. It is concluded that UPS power systems cannot be optimized if the defined acceptable risk level is not well or not at all defined. In addition, it is noted that optimization is difficult or almost impossible if the reliability and availability performance philosophy and methods are not used or not understood.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134550667","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 powering system","authors":"Y. Ueki, T. Washio","doi":"10.1109/INTLEC.1988.22346","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22346","url":null,"abstract":"The authors describe the concept of a powering system for communications network systems and shows its application. The concept involves the integration of the -48 V main power supply and DC-DC converters that form the present powering system used in switching systems. This will eliminate the main power supply, decentralize equipment, and make the system more compact and efficient. In addition, this system is characterized by high efficiency, high reliability, ease of installation, expansibility, and safety.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114950754","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":"Thermal control wall for telecommunication equipment rooms","authors":"M. Nakao, K. Ohshima, H. Jitsukawa","doi":"10.1109/INTLEC.1988.22362","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22362","url":null,"abstract":"The authors describe the feature and operation of the thermal control wall (TCW) system, which combines an exterior wall and cooling system. It can vary its heat transmission coefficient from one to ten times that of an ordinary wall. The TCW cools rooms efficiently, using cool outer air during the winter. The TCW can decrease the load on air conditions if used jointly with them, and save energy as a result. The TCW, which has been installed in a telecommunications office building, is estimated to save 20% of annual cooling energy, according to actual data.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129759684","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 revised approach to hybrid system design","authors":"S. Samuelsen, B.R. Bredesen","doi":"10.1109/INTLEC.1988.22390","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22390","url":null,"abstract":"The Norwegian Telecommunications Administration (NTA) has developed a revised approach to hybrid power-system design using wind generators to power telecommunications systems in remote areas. The authors describe the techniques and methods adopted and the expected results form this revised design. The focus has fallen on improving the utilization of waste heat from the fuel-fired part of the power system and providing better accessibility for service and maintenance. The renewable power part, namely the wind generators, have been particularly difficult to service during icy/windy weather conditions, when climbing towers can become quite a hazard. To overcome this problem, towers have been designed to allow for servicing without climbing. The BARK project at Sprinklerfjell, being put into operation in January 1988, will be the southern-most operated within the NTA Qualification Test Program with the least favorable access to natural (wind) energy.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129011407","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 microprocessor based controller for remote site PV systems including hardware design criteria and advanced control algorithms","authors":"D. Danley, K. Gerken","doi":"10.1109/INTLEC.1988.22376","DOIUrl":"https://doi.org/10.1109/INTLEC.1988.22376","url":null,"abstract":"The authors evaluate the performance of a microprocessor-based controller developed for remote-site photovoltaic (PV) systems. They also review ongoing advances in the concept of intelligent controls. It is concluded that a reliable microprocessor-based power system controller offers significant advantages over analog controls for remote site PV and PV hybrid systems. The digital control logic allows customization in software rather than hardware, and expansion capabilities provide for the ability to control more complex power systems anticipated in the future.<<ETX>>","PeriodicalId":169486,"journal":{"name":"10th International Telecommunications Energy Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125519372","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}