Controlled-Bus Architecture with Voltage Equalization: a system approach to higher efficiency in low voltage DC distribution

摘要

“Central Offices” for Telecommunications have been historically powered by a wide range,negative-referenced 48V distribution system [1, 2]. The need for simple, direct battery-powerbackup has been the main driver behind this choice, which is regulated by global organizationsstandards [3]. The relative simplicity of this distribution scheme has an immediate implication:line-card and server power systems need to accommodate for the wide input voltagerange, which implies reducing both distribution and power conversion efficiency [4]. As powerlevels increase, system designers are challenged to thermally manage more and more power[5]. This paper describes an architectural approach (enabled by a particular converter configurationcalled “equalizer”), which not only increases the overall power system efficiency butalso reduces the losses on line cards and servers.