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This paper points out some particular items of the CCITT handbook dedicated to power supply for telecom on remote sites. Considering experiences feedback of the CNET. the topic of hybrid systems combining photovoltaic and Diesel is specially emphasized.
An improved soft-switching PWM full-bridge DC-DC converter is presented. This employs a tapped inductor for low-pass filter to minimize a circulating current flowing through the transformer and switching devices. By using the tapped inductor and a saturable reactor(s), the converter achieves soft-switching with both low commutating and low circulating currents resulting in low switching and conduction...
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...
A fast growing segment of the telecom industry is the integration with equipment from the computer market. This type of equipment will be used by operators for providing new services throughout the telecom network. Sparked by the growing use of such "service providing equipment", the use of existing -48V and -60V DC Power Plants will be more widely spread, and reduces the need of conventional...
This paper will describe a new interconnecting system for numerous photovoltaics and utility line. In this system, each of dc-dc converters derives the maximun power from each of photovoltaics for any daylight strength. Outputs of converters are connected to dc bus line. The inverter sends power from dc bus line to the utility line. The inverter are automatically synchronized to the utility line by...
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 technical possibilities described and the example of the Dottistrasse in East Berlin (only one of many but certainly the largest) show in a vivid way how old and new types of telecommunications equipment can be fed from a common power supply without complications. These solutions can be an example, especially for countries where the telecommunications administrations face problems similar to those...
The paper describes the activities of Alcatel SEL and her subsidiary Alcatel SEL RFT in the states Kazakhstan and Russia regarding stationary DC power plants. The Hanover fair "CeBIT" of 1992 was the starting point with the signing of some important contracts with the Telecommunication Ministry of Kazakhstan. Everything began with a training exchange of the digital switching system S12 in...
The paper lists the target features of telecom rectifiers, and discusses how they can be realized in cost-sensitive, sub-kilowatt, single-phase-input rectifiers. Several previously proposed approaches are analysed and new possibilities are suggested.
This paper describes a new developed telecom rectifier. The device is fed by the usual mains voltage, has state of the art technology as well as high requirements especially for the efficiency. Also the suppression of interferences to the environment is of importance. This includes EMI and low harmonics on the line input current. All these conditions need a very careful design. A new method is used...
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