Telecommunications Energy Conference, 1992. INTELEC '92., 14th International

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  • Fourteenth International Telecommunications Energy Conference - INTELEC '92 (Cat. No.92CH3195-5)

    Publication Year: 1992
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    Freely Available from IEEE
  • Simulation and experimental results for class D series resonant inverter

    Publication Year: 1992, Page(s):153 - 159
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    A numerical analysis of a Class D zero-voltage switching inverter in the time domain is presented, together with experimental results. A discrete-time state-space approach is used for simulation. The algorithm is fast, easy to implement, and suitable for systems with high spikes in the waveforms. Analysis shows that switching losses can be reduced by using a dead time in the transistor drive volta... View full abstract»

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  • Harmonic distortion reduction schemes for a new 100 A-48 V power supply

    Publication Year: 1992, Page(s):524 - 531
    Cited by:  Papers (10)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (460 KB)

    A new modular 100 A, 48 V power supply is presented, and techniques for improving the performance of its preregulator are described. These techniques address traditional shortcomings of the boost converter topology, such as uncontrolled diode reverse recovery, switch voltage overshoot, and EMI emission/susceptibility. Experimental results are used to evaluate the merits of each circuit variation a... View full abstract»

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  • Stand alone solar powering for fiber-in-the-loop systems

    Publication Year: 1992, Page(s):104 - 111
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (484 KB)

    A key concern in fiber-in-the-loop systems is reliable powering of end-loop optical network units (ONUs). The technical and economical feasibility of using stand alone solar-photovoltaic (SAS) systems for powering these units is examined. Arrays of photovoltaic cells located at or near the ONU are connected to a battery and the ONU electronics. During normal sunlight conditions, electricity from t... View full abstract»

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  • PWM-converter-circuit for UPS-systems with galvanic isolation by a medium-frequency-transformer

    Publication Year: 1992, Page(s):160 - 164
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    A pulse width modulated (PWM) power converter circuit for uninterruptible power supply (UPS) systems is presented. A description of the currently employed UPS technique is given. A UPS system for 50 Hz output operating in conjunction with a medium-frequency transformer is described, and system advantages are indicated. A good control rate with differentiated loading conditions is achieved View full abstract»

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  • Thermal runaway-a system solution for a system problem

    Publication Year: 1992, Page(s):18 - 21
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    Thermal runaway is a potentially destructive failure mechanism known to exist in virtually all lead/acid batteries. It is more likely to occur in valve-regulated (also called sealed or maintenance free) batteries, because the power density tends to be much higher, and the cooling poor. Specific problems encountered in the region of eastern Pennsylvania are described and before- and after-market so... View full abstract»

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  • Input current shaper using Cuk converter

    Publication Year: 1992, Page(s):532 - 539
    Cited by:  Papers (109)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (616 KB)

    The Cuk converter with integrated magnetics when used for input current shaping exhibits advantages over other topologies. When the `ripple steering' mechanism is employed, essentially zero input and output current ripples are obtained for all operating conditions, and the size of the magnetics can be significantly reduced. The discontinuous inductor current mode (DICM) with no current feedback lo... View full abstract»

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  • Review of suitable topologies for on-board DC/DC converters in distributed power architectures for telecom applications

    Publication Year: 1992, Page(s):59 - 65
    Cited by:  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    Distributed power systems architectures have been proposed as an optimal choice for many telecommunication applications. In these architectures, the DC/DC conversion stage is an on-board converter with very hard specifications in terms of efficiency and size. Some of the most usual specifications for telecom on-board DC/DC converters are considered, and the most suitable topologies are reviewed fo... View full abstract»

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  • Hybrid power system for a remote microwave repeater site in the Dominican Republic

    Publication Year: 1992, Page(s):389 - 391
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (248 KB)

    The Compania Dominicana de Telefonos (CODETEL) operates several remote microwave repeater stations as a part of the Dominican Republic's microwave communications network. These repeater sites are powered by various combinations of power sources including solar photovoltaic, wind turbines, diesel generating sets, and grid-connected AC power, in both stand-alone and hybrid power system architectures... View full abstract»

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  • Intelligent battery system for fiber in the loop

    Publication Year: 1992, Page(s):112 - 116
    Cited by:  Papers (3)  |  Patents (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB)

    The use of a local power supply system for fiber in the loop usually takes power from a commercial power source near the terminal. If a power failure interrupts the power supply, power is taken from a rechargeable battery in the power-supply unit. An intelligent battery system is introduced. This system has a control circuit which monitors the rechargeable battery in the local power supply. The co... View full abstract»

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  • A 3-phase inverter using a ferroresonant transformer assembled on a single laminated core

    Publication Year: 1992, Page(s):165 - 171
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    A DC/AC inverter system is described. The device uses a 3-phase ferroresonant power transformer, constructed on a single 3-leg magnetic core, to supply an isolated balanced 3-phase output voltage with variable balanced or unbalanced loads. Test results indicate that the single 3-leg core transformer arrangement performs as well as a dual-core arrangement and requires less time to assemble and inst... View full abstract»

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  • Use of temperature compensating device in telecom cabinets exposed to outdoor environments

    Publication Year: 1992, Page(s):41 - 46
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    A new temperature compensating device designed to control valve regulated lead acid battery float voltage on telecommunication power plants is introduced. Although developed for the remote subscriber carrier systems which are exposed to outdoor environments, it will operate on any type of telecommunication power plant in any environment. This device is electrically connected between the rectifier ... View full abstract»

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  • Charging abuse-how well can a VRLA battery cope?

    Publication Year: 1992, Page(s):22 - 27
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    It is shown that the resistance of a valve regulated lead acid (VRLA) battery to overcharging can be quantified to a large degree. Two aspects are examined: measurement of the Tafel relationship of a cell, and thermal runaway testing. Practical implications of the tests results are seen in applications involving constant potential charging, and also those in which constant current charging is used... View full abstract»

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  • On the design and experimentation of a high performance 25 A/48 V rectifier unit

    Publication Year: 1992, Page(s):540 - 547
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    A 25 A/48 V rectifier unit to be used as a battery charger for telecommunication applications is described. The unit is based on a modified version of the full-bridge zero-voltage switching pulse width modulated (FB-ZVS-PWM) DC/DC converter, which operates with no switching losses from no-load to full-load. The input stage is composed of a single-phase AC-to-DC converter with two diodes and two th... View full abstract»

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  • Monitoring of remaining discharge time of batteries

    Publication Year: 1992, Page(s):205 - 211
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    A technique for determining the remaining discharge time of batteries is described. The calculation method, based on discharge characteristic function, is presented, together with a process for calculation of discharge capacity. A device to monitor the remaining discharge time of 10 types of batteries is developed. Digital indication with microprocessor control is shown to provide accurate indicat... View full abstract»

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  • Square against sine-the future of high frequency power conversion

    Publication Year: 1992, Page(s):66 - 73
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    Various types of sine-wave resonant and quasi-resonant high-frequency converter topologies have been studied by the power supply department of Siemens' public switching division. Prototypes have been tested and results compared. Special attention has been devoted to practical problems such as physical limits of components, tolerances, life utility, and manufacturing process, taking into considerat... View full abstract»

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  • A manipulation and control scheme of paralleled diesel-generating sets in China

    Publication Year: 1992, Page(s):392 - 398
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    Taking paralleled diesel generating sets as an example, the practical controller requirements of paralleled AC power supplies and the characteristics of parallel operation are analyzed. An automatic manipulation control scheme by means of a `four-position' switcher is proposed. New ideas of load operation control and synchronizing control are presented. The novel optimal control scheme and fast ph... View full abstract»

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  • A special buck-boost converter

    Publication Year: 1992, Page(s):438 - 444
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    A special step-up/down converter is investigated. The basic function, the stationary relationships, the small signal behavior, the position of the poles and zeros and the dimensioning are discussed. For a model converter, simulation and measurement results are compared. The advantages of this converter are: the duty ratio is always larger than 0.5 giving, an easier realization of a low-loss snubbe... View full abstract»

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  • Fiber in the loop systems powering: Bellcore requirements

    Publication Year: 1992, Page(s):117 - 123
    Cited by:  Papers (5)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (420 KB)

    Power and reserve power are significant challenges to fiber in the loop (FITL) deployment. Power requirements must reflect short-term needs and the ability to move to future networks and capabilities. Major requirements in the power area are identified, together with open issues, including power system communications with remote operations systems, common optical network unit/host digital terminal... View full abstract»

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  • Practical design methodologies for load resonant converters operating above resonance

    Publication Year: 1992, Page(s):172 - 179
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB)

    Practical design techniques for load resonant power converters operating above resonance are presented. The design procedures use a sinewave approximation for the waveforms (i.e., only the fundamental components are considered). This in turn allows simple analyses of the converters based on AC complex analysis. Based on these analyses, design procedures are developed for the series, parallel, and ... View full abstract»

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  • Extending the range of soft-switching in resonant-transition DC-DC converters

    Publication Year: 1992, Page(s):343 - 350
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (532 KB)

    Resonant-transition converters are attractive for high-frequency power conversion because they feature zero-voltage switching (ZVS) and low conduction loss with constant frequency, pulse width modulated (PWM) control characteristics. In many practical applications, it is difficult for these converters to sustain both ZVS and low conduction losses over a wide operating range. The use of saturable m... View full abstract»

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  • Statistical-mathematical model optimizing photovoltaic array inclination

    Publication Year: 1992, Page(s):294 - 299
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    The problem of photovoltaic array inclination is addressed. Fixed inclination is inadequate for certain periods of the year so that periodic adjustments are required to optimize the capture of surface irradiation. The system described operates at intermittent duty rating. Data are collected and processed for a specific time period, and the optimum array inclination for tracking at different period... View full abstract»

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  • Simulated ONUs for battery characterization in the local loop: a status report

    Publication Year: 1992, Page(s):88 - 95
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (744 KB)

    In fiber-in-the-loop systems power to the optical network units (ONUs) that are located at the far end of the fiber can be provided by local powering, in which power is supplied by a commercial power source located near the ONU; when this source fails, power is supplied by batteries co-located with the ONU. To determine if small battery systems can be made to exhibit 7 to 10 year lives in a New Yo... View full abstract»

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  • Thermal runaway prevention by control of float voltage as a function of a battery temperature

    Publication Year: 1992, Page(s):47 - 50
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    Experimental data supporting the theory that control of float voltage as a function of temperature prevents thermal runaway in valve regulated lead acid batteries in DC reserve systems for telecommunications are presented. The data show that the control system must have adjustable control coefficients that allow for various temperatures inside the battery array depending upon the application. To p... View full abstract»

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  • National Power Laboratory Power Quality Study results based on 600 site-months

    Publication Year: 1992, Page(s):378 - 383
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    The preliminary report of the National Power Laboratory (NPL) Power Quality Study is based on 600 site-months of data. Disturbance monitoring is done at the standard wall receptacle at each location. This yields a true picture of the disturbance exposure rate for typical 120 V AC loads. This exposure encompasses both utility and load-generated disturbances. A typical site will have 445 power distu... View full abstract»

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