INTELEC 05 - Twenty-Seventh International Telecommunications Conference

This paper examines the array of challenges currently faced by the telecom industry, including circuit to packet network migration, voice over IP (VoIP) telephony, and reliance on the Internet for worldwide commerce, that have led up to an increased reliance on high-quality extended backup power. It assesses traditional backup solutions in the context of the history of the telecom industry and com... View full abstract»

We have studied the characteristics of a shared distribution fuel cells system which is shared by a community center and many houses surrounding it. The system was confirmed to be effective. The utilization factor of the fuel cells was improved by about 20%, decreasing the generation cost of fuel cells and the environmental burden View full abstract»

Most of UPS-systems use batteries as back-up energy source. Usually here we find lead-acid batteries or NiCd batteries when its a high ambient temperature. If longer back-up times are required an additional diesel generator will provide the energy. This paper presents the results of some tests, where a fuel cell system generates the back-up energy on a 48 V level View full abstract»

The DC power supply systems of telecom applications for broadband and Internet access have increasing energy demands. However, in many cases the available space for the installation is already used to its maximum. A lithium ion battery can be the solution because of the higher energy density of about 150 Wh/kg and 380 Wh/l, good discharging performance and an operating range from -30degC to 60degC... View full abstract»

Mobile terminals and communicating computers have generalized with lots of optimisation in their design and power. It seems that today appears a gap between the best known batteries and the still increasing power requirement of broadband multimedia terminal for a given mass and volume. This paper presents the probable energy requirements targets and lots of ongoing researches on power consumption,... View full abstract»

Advances in low power design open the possibility to harvest energy from the environment to power electronic circuits. A piezoelectric element is capable of transform mechanical energy into electrical energy. Several methods are possible to efficiently store the generated electrical energy. Direct discharge method is here analyzed for a realistic piezoelectric current source waveform when the mech... View full abstract»

Power conversion efficiency has been the standard means of comparing the performance of the power converter as it provides a simple and direct way to evaluate a given converter's performance while evaluating the heat sinking and cooling requirements at the same time. The efficiency tool works very well when we have established standard input and output voltages that are more or less fixed in value... View full abstract»

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 regu... View full abstract»

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's1) are hybrid devices that combine the advantages of mechanical circuit breakers that offer lower contact resistance and power loss w... View full abstract»

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 ... View full abstract»

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. Whe... View full abstract»

TIM is the most international Company of the Telecom Italia Group and is the first mobile telecommunication operator in Europe for number of subscribers and leader in the domestic market. TIM has in the innovation its strength point. In a market characterized by a competitive context and by a fast technological evolution, the attention of the management is concentrated in the development of the in... View full abstract»

Current telecommunication infrastructure needs a large number of small and decentralised installations like e.g. remote digital line units (RDLU) in wire-line networks or base transceiver stations (BTS) in mobile networks. Selected in respect to minimum infrastructural costs, especially power system components often lack supervision functionality that allows optimizing long-term reliability or ser... View full abstract»

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 ... View full abstract»

Since the islanding of the PV generation systems can cause a loss of lives and damage to equipments, it has to be avoided by a reliable detection system. In this paper, a novel anti-islanding method is presented. The PV generation system applied to the proposed method maintains the real average output power components of the system by MPPT control, which is similar to the conventional PV system. H... View full abstract»

A study of a micro-hydro run-of-the-river project using a squirrel cage induction generator is presented. A water current turbine, propeller type, is considered. A three-phase voltage source inverter is used to establish with deadbeat control on the AC side, the required currents to excite the generator. A DC control loop with PI controller is used to maintain the DC bus voltage constant with roto... View full abstract»

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 te... View full abstract»