{"title":"A novel 12 kW switch mode power supply","authors":"B. Inniss, G. Carli","doi":"10.1109/INTLEC.1990.171230","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171230","url":null,"abstract":"A new 200 A switch mode power supply (SMPS) for telecommunications applications was developed. The authors detail the most significant electrical characteristics of the SMPS. The power transfer mechanism is based on a full bridge PWM configuration. The basic switching device chosen was the power MOSFET. This semiconductor is packaged by various companies in isolated modules containing four parallel dies. The unit uses two of these modules in parallel as one switch so that a total of eight modules are utilized. FETS were chosen over other devices because of their low drive requirements, speed, and their sharing characteristics when operating in parallel. The stray capacitances associated with high power switching devices, in conjunction with the use of saturable beads, provide for some desirable inherent snubbing effect. A description is given of power transformer design, power factor correction, and of some precautions in designing for optimally low EMI emission and the highest lightning surge protection.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116882430","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":"Applications for a single cell discharge/recharge test set for battery plant capacity determination","authors":"B. Meyer, J. R. Elliott","doi":"10.1109/INTLEC.1990.171290","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171290","url":null,"abstract":"Recent technical results are described from a study of a single-cell discharge/recharge test of lead acid batteries. The test has been developed to meet the telecommunication industry's need for a means of accurately and efficiently determining if a battery string is still usable past its cells' expected life. The testing procedure and the equipment used are described, results and field experience are discussed, and the benefits of the procedure are outlined.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125400606","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":"An 'in vivo', in place, regulated battery string ampere hour discharge tester","authors":"M. Wolpow","doi":"10.1109/INTLEC.1990.171302","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171302","url":null,"abstract":"Battery string testing equipment is described that enables the testing of ampere-hour discharge capacity of individual cells or battery strings without the use of dummy loads. Battery discharge energy is fed directly into the load bus under closely monitored and metered conditions. This equipment is portable, mounted on wheels, and designed for the narrow aisles in the telephone central offices.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126651972","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 frequency domain modelling of a series resonant DC/DC converter","authors":"P. Jain","doi":"10.1109/INTLEC.1990.171270","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171270","url":null,"abstract":"A novel frequency domain modeling of a series resonant DC/DC converter in continuous-current mode is presented. The method is general and can be applied to study the performance of the converter for both variable frequency and pulse width modulation control techniques. Generalized curves for voltage gain Eo/Ei and phase-shift phi are provided. It is shown that once the values of Eo/Ei and phi are known, steady-state performance of the converter can easily be obtained by using nth harmonic equivalent circuits.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114520000","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":"Stationary battery design and usage and its impact on life","authors":"S. Misra","doi":"10.1109/INTLEC.1990.171255","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171255","url":null,"abstract":"The design, manufacture, and testing of standby battery products for various uses and the evolution of modern uninterrupted power system (UPS) battery designs are discussed. Some ongoing and past test results that affect standby battery design, particularly with respect to ripples, depth of discharge, grid alloy, and the retention system, are discussed. Shedding due to high rate cycling has been identified as the main failure mode for either standby battery systems of UPSs, and improved containment of positive active material to prevent this will be the key to emerging UPS designs. Cycling may become an even greater issue for UPS products in the future, for which the product 'life' will have to be redefined around a combination of calendar and cycle use.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122104019","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":"New type UPS 'BIROS-X'","authors":"Y. Yamaoka, O. Wada, T. Yamamoto, S. Kikuda","doi":"10.1109/INTLEC.1990.171280","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171280","url":null,"abstract":"A new uninterruptible power system (UPS), called BIROS-X, is described which is highly intelligent, small in size, and highly efficient. The noise level of the BIROS-X is very low, using the technology of inaudible high frequency pulse width modulation (PWM) control. Higher efficiency is achieved by using insulated gate bipolar transistors (IGBTs) in the inverter and the rectifier. The inverter is a full-bridge circuit of four IGBTs which switch at 9.6 kHz with a modulated width of a sine wave. As a result of the high-frequency switching of the IGBTs, the AC filter size is now 10% compared with those of four conventional UPSs. The rectifier consists of 6 IGBTs which switch at 16 kHz to make the input current sinusoidal and to make the power factor 98% at the full load, with a distortion factor of less than 10%. Due to various sealed lead-acid batteries which may be used for the UPS, newly devised charging methods can be adapted for each case. The functions of the operation panel include metering, operation guidance (starting up, switching off, a maintenance bypass switch), and an alarm indicator.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129584469","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":"Gas evolution and thermal behaviour of valve regulated lead acid batteries under abnormal operational conditions","authors":"D. Berndt, E. Meißner","doi":"10.1109/INTLEC.1990.171240","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171240","url":null,"abstract":"Heat generation in a lead acid battery during energy conversion was studied. The temperature effects which are to be expected were evaluated using the fundamental laws of heat dissipation, and a computer program was established to predict the heat balance of a battery. The results are compared with overcharge experiments carried out with valve regulated block-batteries of the type Vsb 6905 T (6 Volt; K/sub 10/=85 Ah, Microglas absorbent version) including gas measurements and gas analysis. It is suggested that valve regulated lead acid batteries, especially when designed for short bridging periods, should be equipped with a monitoring system to avoid critical situations in case the voltage controlling system fails. The temperature of the battery is one of the parameters suited for this kind of monitoring.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126974177","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 batteries as a principal component in DC UPS systems","authors":"T. Suntio, A. Glad","doi":"10.1109/INTLEC.1990.171278","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171278","url":null,"abstract":"The authors discuss the duties of batteries in DC uninterruptible power supply (UPS) or telecommunications power systems. They show how the battery system affects the DC UPS system reliability and availability performance, discuss the impact of public power and engine alternators on battery sizing, and determine the essential parameters to be monitored. Also discussed are the issues of battery fault detection and the temperature compensation of battery voltage.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131472997","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 simulation for power equipment using natural cooling","authors":"F. Gabrielli, G. Meli","doi":"10.1109/INTLEC.1990.171304","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171304","url":null,"abstract":"A model is described which simulates the thermal behavior of power equipment installed in a metal cabinet, predicting the course of the internal thermal gradient and of the convective flows in conditions of natural cooling by convection. The proposed method proceeds from the calculation of the difference in pressure which is created inside the equipment due to density variation of the air as it is heated by the energy dissipated from the various components. The behavior of the internal temperature and the thermal increase between the inflow and outflow air for different ambient temperatures can be determined by subsequent iterations. The method of calculation provides the visual graphics of the internal thermal gradient, starting with the geometrical data of the equipment and of the components with relative power dissipations.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131620679","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 mathematical model for a series resonant converter","authors":"C. Cutrona, C. Di Miceli, L. Fiorella","doi":"10.1109/INTLEC.1990.171268","DOIUrl":"https://doi.org/10.1109/INTLEC.1990.171268","url":null,"abstract":"Analysis is presented of a linear dynamic model, around the static operation point, for a series resonant converter operating with small amplitude modulating signal and a modulation factor less than one. Comparison of the theoretical results with those found experimentally shows the validity of the proposed model also as regards the shift of the dominant pole with switching frequencies approximate to the resonance frequency. This happens to be particularly precise for values of Q greater than 1.5 where the first harmonic approach is much more valid. In conclusion, the proposed model approximates very closely to the behavior of the physical system for values of f/sub S//f/sub O/ greater than 0.6 and values of Q greater than 1.5.<<ETX>>","PeriodicalId":264940,"journal":{"name":"12th International Conference on Telecommunications Energy","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131792848","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}