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This paper describes the application of photovoltaic (PV) solar cells in planar antenna structures. The radiating patch element of a planar antenna is replaced by a solar cell. Furthermore radiating slots are built due to the cell spacing in a solar cell array. The original feature of a solar cell (DC current generation) remains, but additionally the solar cell is now able to receive and transmit...
In spite of a number of new, alternative power supply back up technologies, batteries are here to stay. Continuous monitoring of back up systems on the battery level becomes a vital factor of many mission-critical installations. In this paper, the authors explore the possibilities of implementation of new generation, state of the art battery monitoring systems based on wireless technology. This technology...
Charge balance is known to be an essential consideration in series valve-regulated lead-acid (VRLA) battery applications. Conventional applications use passive equalization to maintain balance: periodic overcharge sequences. Active equalization uses external circuits to enforce charge balance without the need for overcharge. There is little published data to show the potential value of active equalization...
Those of us who depend on batteries often feel that we are flying blind. Some of us use instruments to help navigate the question: "what condition are our batteries in?" Yet, most of us want something simpler to use - something more definitive - less ambiguous - more useful. When you first read through literature that has been written over the last decade and a half on the subject of battery...
The IEC 61427 Ed.2 applies to all lead-acid and nickel-cadmium cells and batteries for photovoltaic energy systems (PVES). This standard gives general information relating to the requirements of the secondary batteries used in PVES and to the typical methods of test used for the verification of batteries performances. The objective is to assist the specifier in the understanding of the purpose of...
Lithium-ion batteries offer many attributes that are attractive for telecom reserve applications relative to flooded and VRLA technologies. These attributes include much higher energy density per unit weight and per unit volume, no hydrogen outgassing, no thermal runaway mechanism, and much lower steady-stage float current. Lithium-ion batteries are particularly attractive for sites where floor space...
In most wire communication systems, the communication lines are also utilized as the power lines. In that case, the powered terminals need to separate AC signals and DC supply power. Moreover, the input impedance looking into each terminal from the communication lines should be high because a lot of terminals are connected. Well-known AC/DC separator is constructed by inductors and capacitors. When...
In this paper, an AC-DC-AC three-phase transmission system that employs two six-switch inverters is studied. The inverters are connected by an inductive DC link, and are controlled in order to ensure a high power factor at the source side, a regulated voltage at the DC side and low-distorted currents at the load side. The inverters are modeled in the average regime in order to design suitable regulators...
Conventional mechanical circuit breakers protect AC and DC circuits from overload and short circuit conditions, and also meet the required physical isolation criteria after contact separation. They are limited in life because of mechanical degradation. Existing ESS's are hybrid devices that combine the advantages of mechanical circuit breakers that offer lower contact resistance and power loss with...
The implementation of modern optical modules in distributed power system of optical network equipment may not be a straight forward task. The major challenge comes from both the variety and complexity of optical modules used. This work analyses the issues associated with powering the optical modules and explores the use of the traditional distributed power and intermediate power bus architectures...
In this paper, an approach for the design of predictive controller for fourth order buck topologies is proposed. The controller is designed to achieve the load voltage regulation against load and source disturbances. A zero ripple technique is used to reduce the ripple in inductor current. The dynamic characteristics of the coupled fourth order buck converter are compared with the uncoupled converter...
Fuel cells have a high potential to store a higher amount of energy in comparison to lithium ion accumulators and other secondary batteries. About all this euphoric assessment of the potential of this technology sometimes the cost and state of the art facts fail in oblivion. On this we look carefully on prices and requirements from the applications point of view to develop successful mass and niche...
Hydrogen fuel cells provide a promising new method of power generation and energy storage for both mobility and stationary power applications. Hydrogenics Corporation is currently engaged in the design, development, and demonstration of proton exchange membrane (PEM) fuel cells for a wide range of applications, including backup power for telecommunication infrastructure, data centers and other mission...
Fuel cell products and systems are still about to break through in their markets. Among many other applications which are currently under development most success for a market entry today is seen for stationary applications where conventional batteries often operate reach their technical limits. A fuel cell system in combination with a UPS application with a power output of netto 2 kW at - 48 VDC...
Electricity, gas and heat are core products of the E.ON group. It is therefore no doubt about that the fuel cell - as an innovative technology for converting gas into electric power and heat - is of considerable interest to E.ON. Fuel cells have raised many expectations both in politics and in economics in regard to climate protection and energy efficiency. Fuel cell plants can be installed close...
We have already reported the novel digital control method "static model reference" which is the improved smart digital reference of output voltage for its digitally controlled dc-dc converter. The circuit mechanism and the static characteristics have been cleared. This paper presents dynamic characteristics of the digitally controlled dc-dc converter with static model reference. Moreover,...
The energy supply systems of telecommunications power stations are based on rectifier units of high power factor, compact with high efficiency. To obtain high power factor it is necessary to use in the ac-to-dc conversion stage a power factor pre-regulator, which leads to an increase of the input voltage levels of the dc-to-dc stage. In order to reduce the voltage efforts over the switches of the...
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