Re-architecting 48V power systems with a novel non-isolated bus converter

Intermediate Bus Architectures have been popular in the telecom industry for their ability to easily accommodate a wide variety of loads from the telecom industry's common 36-60V distribution voltage range [1]. A key performance metric of telecom power systems is based on the performance of the bus converter used to enable this architecture. While point-of-load converter performance is mostly driven by advances in semiconductor technologies, bus converter performance is highly dependent upon converter topology. Performance metrics impacted by bus converter topology include both power conversion efficiency [2] and power system stability [3]. The “Sine Amplitude Converter” bus converter topology [4, 5] has proven to be superior to traditional topologies [6] in virtually every significant performance metric, including conversion efficiency, power density, footprint, bandwidth, and system stability. As telecom power system requirements have matured, the “Sine Amplitude Converter” may now enable further system improvements. Specifically, grounding requirements of telecom systems are compatible with bus converters that do not require galvanic isolation [7]. This paper presents series-connected bus converters [7] optimized for use in non-isolated bus architectures (NIBA) by having primary and secondary converter stages connected in series.