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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.
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...
The explosive growth of mobile applications requires more bandwidth, which, in turn, requires more energy as well as additional investments in network infrastructure-money that service providers must find ways to recover.
We present a quantitative analysis of the benefits of the 380 VDC power distribution system compared to the current −48-VDC power supply system. The analysis is based on models of typical distribution configurations in global telecommunication sites and takes into account codes, regulations, and practices for wiring and voltage drop comparison between centralized/decentralized 48- and 380-VDC. In...
A consideration of short-circuit protection in high voltage direct current (HVDC) distribution system is written in this paper. There are some types of energy sources in HVDC system, and the behavior of short-circuit current is affected by the way to rectify. Therefore, it may be more complicated to protect short-circuit in HVDC system than it is in AC system. In this study, a protection technique...
Thermal runaway scares the heck out of many people; especially those that do not know how to detect that the conditions are being set for a thermal runaway. While thermal runaway can occur in most battery chemistries such as lead acid either VLA or VRLA, or Ni-Cad, or Lithium Ion, this paper is going to restrict itself to the VRLA technology.
Design considerations and performance evaluations of the recently introduced three-phase, two-switch, zero-voltage-switching (ZVS), power-factor-correction (PFC), discontinuous-conduction-mode (DCM) boost rectifier, named the Taipei rectifier, are presented. The performance evaluation was done on a 3-kW, 400-V-output prototype designed to operate with a line-to-line RMS input voltage from 180 V to...
This paper presents the novel driving technique of synchronous rectifier (SR) for the LLC converter. The unique characteristic of “Vo*D=constant” of LLC converter is utilized to predict optimal duty ratio D, where D is the conduction period of secondary diode. This technique does not need the sensing of SR current neither SR voltage. The technique is confirmed by experimentally.
Data centers (DCs) are considered critical loads that require premium power from utilities to ensure reliability at all times. Microturbine (MT) generation systems are becoming important in DCs, not only as distributed generation (DG) for supplying electricity, but also for providing cooling and heating functions, which is known as combined cooling, heat and power (CCHP) or tri-generation. This paper...
This paper discusses the operating characteristics of push-pull type series resonant converter. The AC equivalent model and AC analysis of push-pull type series resonant converter are confirmed by analytically and experimentally. Moreover, the operating characteristics of push-pull type series resonant converter including SR are also investigated.
Battery and DC power system assets management is a critical and important part of any operating Telco's service reliability and availability plans. This needs to be addressed within tighter constraints on CAPEX for assets that don't directly generate revenue and in an environment of an aging infrastructure.
This paper describes the configurations of semiconductor circuit breakers we developed for higher-voltage direct-current (HVDC) power feeding systems. Semiconductor breakers have some merits. The shutdown parts of the breakers are compact and can be controlled remotely. In addition, they do not need to be replaced after shutting down a short circuit. When semiconductor breaker shutdown overcurrent...
A grid tied photovoltaic (PV) array is considered for this work. The novelty is in the use of a single-phase controlled rectifier with a backstepping controller to track the maximum power operating point (MPOP) for a string of PV arrays under varying atmospheric conditions. The stability of the controller is demonstrated by means of a Lyapunov analysis. A circuit level simulation demonstrates that...
380V DC distribution is becoming a necessary choice for new telecom and datacenter power infrastructure [1,2,3]. As state-of-the-art computing, routing and optical hub equipments continue to require more power, classic 48V distribution quickly becomes expensive to install and operate due to I2R losses; at the same time, AC distribution utilizing AC UPS becomes too expensive and complicated. While...
Telecommunication operators must manage many types and models of power equipment from many manufacturers each with different characteristics. With Telco's globally reporting strong pressure on CAPEX reduction, it is important to develop capability not only of predicting end-of-life of equipment, but also of managing the vast number of types, makes and models used in a variety of environments. Delayed...
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