-48 V DC computer equipment topology-an emerging technology

Step-up switching-mode converter with high voltage gain using a switched-capacitor circuit

“…Apparently, for a certain set , , can be chosen such that to get even 100% efficiency. The problem is that, by using a given number of capacitors, there is a maximum achievable value for [9] (9) In typical SC step-up converters, the load voltage has to be regulated at a certain value (which, of course, can be only lower than achievable), and this is the value that appears in (2). For example, in [7], a 5-12-V step-up converter was designed, requiring and giving, according to (2), .…”

“…The information industry uses uninterruptible power supplies, but the backuptime provided by them is not enough; a better choice for providing longer reverse time is to use the -V telecom power supply and to boost it to the necessary 380-V intermediate dc bus. This application requires no isolation in the dc-to-dc step-up front-end, since the isolation is provided by the following stages, which transform the 380-V bus to the voltages required by the servers for data processing [2].…”

“…The information industry uses uninterruptible power supplies, but the backuptime provided by them is not enough; a better choice for providing longer reverse time is to use the -V telecom power supply and to boost it to the necessary 380-V intermediate dc bus. This application requires no isolation in the dc-to-dc step-up front-end, since the isolation is provided by the following stages, which transform the 380-V bus to the voltages required by the servers for data processing [2].Usual boost converters cannot provide such a high dc voltage ratio. One can not work at a high duty-cycle value, due to the latch-up condition; in a typical example given in [3], where the parasitic resistances in the power stage have been accounted as 1% from the load value, the maximum voltage ratio was 4.7 for operating at a nominal duty cycle .…”

Automatic Resonant Frequency Tracking in Parallel LLC Boost DC–DC Converter

“…is increasingly felt in many recent applications like high intensity discharge (HID) lamps in automobiles (12-120 V) [1], telecom supplies (48-380 V) [2], dc bus supply for grid-side converters in photovoltaic/fuel-cell/battery interfaces [3]- [7] and drive converters in electric/hybrid electric vehicles [8]- [12]. Additional demands on power density require that the source current drawn by these converters be continuous.…”

Energy management system with equalization algorithm for distributed energy storage systems in PV-active generator based low voltage DC microgrids

“…1). The microgrid is formed around a standard 48V dc common bus, which is a kind of low voltage DC power distribution system that is widely used, since it allows working on a live conductor with minimum risk for personal injury and without special safety requirements [21]. Moreover, non-isolated buck DC/DC converters operating in continuous mode are used for the conversion stage of each RES and ESS as proposed in [15].…”