Modern high-availability multi-stage power distribution system for the CMS phase-2 upgrade

The operation of CMS at the HL-LHC requires an upgrade of the readout electronics. These new modern micro-electronics require power at precise voltages between 1.2 V and 2.5 V. We will deliver this power using a 3-stage system, comprising AC-DC conversion to 380 V DC followed by radiation-tolerant 12 V DC-DC power converters feeding radiation-hard point-of-load DC-DC converter. We have studied an industrial 380 V AC-DC conversion system, featuring hot-swappable 3 kW power modules, stackable up to ∼1 MW system. Such systems are candidates for the first conversion step, feeding custom power supplies accepting 400 V DC input voltage. Our tests on one of the commercially available systems purchased from Eltek demonstrated that the system complied with our requirements, most notably in terms of maintainability, availability and power quality. A few measurement plots perceived by authors as particularly interesting are discussed in this contribution.