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BEST is a multi-device platform that allows the automation of the process of identifying a new place to plan the installation of a Base Transceiver Station (BTS), but it can equally well support the evolution of existing BTS after changes occurred in the surrounding area.
In literature, the details of engineering power converters are often discussed in a limited scope. However in practice, the design of such converters entails consideration of the whole circuit as the many subsystems of are inevitably linked together. This paper presents a scripting method to assist in the design of large power converters. Such an approach simplifies iterations in the design process...
This paper presents a novel and reliable DC switch and DC socket for high voltage DC power feeding system, in which the arc does not occur when the are turned on/off and inserted/removed, respectively. The novel prototype DC switch and DC socket have been made. Both are almost same circuit configuration and operation principle and then composed of two mechanical relays and a single MOSFET. It has...
Article 708 was added to the NEC based on needs expressed by the federal government for standards that could strengthen homeland security. Article 708 was directed by the NEC's Technical Correlating Committee Task Group on Emergency and Standby Power Systems for Homeland Security and created by Code-Making Panel 20. Historically, the NEC has been primarily focused on the installation of electrical...
Network remote power feeding provides energy to telecommunications equipment over existing conductors normally used to transport data. Existing and emerging applications for remote powering are discussed along with the safety aspects, standards and limitations of using signal lines at elevated voltages. Finally the added capabilities of a new “digital” power distribution technology known as “Packet...
In recent years, 380V power distribution systems have been attracting attention as high-efficiency and high-reliability power systems that can be used in telecommunications buildings and data centers. The move toward the proactive use of natural energy, meanwhile, has also been gaining strength. Against this background, we have been moving forward on the construction and experimental study of a container...
Circa 20 years ago, a large amount of small and medium distributed DC power systems were deployed in BT's UK fixed network. There is an aspiration to replace rectifiers used in the power systems with modern high efficiency products, but how to make it a good business case? BT in partnership with Huawei has devised a solution that achieves a 3 years ROI with many novel rectifier replacement techniques.
A modified control scheme is presented in this paper to improve the load transient response of DC-DC power converter by utilizing a previously proposed auxiliary circuit which is capable of operating in both boost mode to discharge the output capacitor during load step down transient, and in buck mode to charge the output capacitor during load step up transient. The proposed modified control scheme...
In recent years, 380Vdc distribution systems have been expected to be one of the energy saving solutions for telecommunication buildings and data centers. However, DC distribution systems have various problems. In this paper, We report the results of an investigation of inrush current, including current size, effects and testing methods, as one problem in the construction and operation of 380Vdc power...
Stationary battery energy storage systems are widely used for uninterruptible power supply systems. Furthermore, they are able to provide grid services. This leads to rising installed power and capacity. Lead-acid batteries provide one of the most mature and economically feasible solutions. Although this technology has been known and studied for more than 100 years, a further understanding of the...
Ohmic measurements (Conductance, Impedance, Resistance) have been in use in telecommunications networks for battery state of health assessment since the 1980s. The technology hasa track record of effectiveness and is an efficient tool for as part of an overall battery maintenance program, providing cost and time savings and advance warning of battery degradation in key systems.
This paper presents a fully integrated high voltage charge pump which enables a reconfigurable, energy-efficient multi-band transceiver. Using a high voltage CMOS technology from Austriamicrosystems and a 4-phase charge-pump (DC/DC converter) circuit architecture, up to 120 V supply voltage can be generated from a 3.7 V DC battery using this monolithically integrated circuit. The very small footprint...
Methods to estimate the DC wire loss in photovoltaic (PV) systems are proposed. Root-mean-square (RMS) of the irradiance data is first related to wire losses. Then a statistical model is used to characterize the irradiance data for the PV systems. The β-distribution gives reasonable match of the RMS value for the irradiance data. The result is consistent for different geographic locations.
GE's Power Electronics business, formerly known as Lineage Power, and Verizon partnered on a project sponsored by the United States Department of Energy to design and field trial new technologies aimed at dramatically improving the energy efficiency of power systems supporting information communication technology systems. A variety of energy efficiency upgrade strategies were pursued at five different...
Two voltage levels of High voltage Direct Current (HVDC) systems in China are discussed in this paper. Their rated voltage are 240V and 336V (corresponding working voltages are 276V and 380V). After introducing the principle of the HVDC system, we reviewed the main characteristics \including the voltage ranges, system reliability and maintainability of HVDC system. As large quantity of 240V HVDC systems...
Quantitative analysis of the output current for the multiphase buck converter facilitates the optimal design of the converter. This paper quantifies the output current and its ripple cancellation effect. A universal formula has been derived to express the output current of multiphase buck converter with any number of phases operating at both continuous conduction mode (CCM) and discontinuous conduction...
Improving efficiency of air conditioning in data centers involves improvement of server room operations as well as improvement of efficiency of air conditioning units. This is because server room operations significantly affect the airflow inside the room, and improper airflow results in hotspots. Hotspots result in excessive cooling, which in turn leads to increased energy needed for air conditioning...
In the fields of using green energy such as EV power system and the PV system, the bi-directional DC-DC converter, which is used to control the charge and discharge of batteries, is now attracting more and more attention. In the bi-directional DC-DC converter for the battery charger, the response characteristics and stability of one are key points for the performance of the whole system. However,...
Mismatching effects are major drawbacks existing in today's photovoltaic (PV) solar systems. To improve power system stability and energy conversion efficiency, distributed maximum power point tracking (DMPPT) techniques are developed. In this paper, single-stage DMPPT power management DC-AC inverter architecture (SS-AC-DMPPT) is presented and verified by Matlab®/Simulink® simulation model results...
The purpose of this paper is to present a digitally controlled dc-dc converter with a novel peak current injected technique. In the proposed method, the peak current is able to be detected by using a voltage controlled oscillator (VCO) which is very low cost and the simple delay circuit implemented by the a field programmable gate array (FPGA). As a result, it is confirmed the main switch is turned...
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