Power System Architectures for 400 V DC Distribution What keeps power people up at night? Presentation Overview • • • • • • • • Typical Site DC distribution diagram Rectifier cabinet structure Available building blocks and power system chain Three power system architectures that address most needs Test of proposed DC-DC conversion scheme Small-scale model Transition paths Conclusions What keeps power people up at night? Simplified Block Diagram of DC Distribution for a Typical Site Goal – minimize TCO from AC to the point of load Rectifier cabinet 400V DC Distribution Network Equipment Rack Powered equipment High Voltage Bus Converter + - AC Input ZVS buckboost regulator Current multiplier 380VDC 380VDC GND ZVS buck regulator 2V – 16V Energy storage (battery) Ground ) What keeps power people up at night? 1.xV Rectifier Cabinet: 30kW AC to 380V DC Converter 400V DC Load Distribution Sub-rack Power Conversion and Control Sub-rack Battery Tray Equivalent to existing 48V systems! What keeps power people up at night? Rack Equipment: Power Conversion Engines Sine Amplitude Converter (SAC) ZVS Buck-Boost (or buck) converter 2000 W/inch3 (120 W/cm3), pk = 98% 1800 W/inch3 (110 W/cm3), pk = 97% Implemented as Implemented as High Voltage Intermediate Bus Converter (HV-IBC) Point-of-load Current Multiplier (CM) Equalizer (ZVS-BB) What keeps power people up at night? Regulators (ZVS-BB) Design Philosophy for Rack Equipment ASICs, FPGAs CPU, GPU, memory Maximum use of SAC voltage transformation / current multiplication is paramount What keeps power people up at night? Compliance to ETSI EN 300 132-3-1 with No Impact on Efficiency: Voltage Equalizer Concept An optimal approach to supply voltage range compliance consists in regulating ONLY when the voltage falls below normal operating range (365 V ± 15 V) Implementation Source voltage < 350 V Source voltage ≥ 350 V External OR-ing bypass (available today) Internal +IN to +OUT state (under design) What keeps power people up at night? Three power system Architectures that address past, present and future implementations 1. Legacy equipment: External Adapters 2. Upgraded equipment: Bus Converter Retrofit 3. New Equipment: Factorized Power Architecture PLACE YOUR LOGO HERE What keeps power people up at night? Legacy Equipment: External Adapters Objective: to enable existing 48V DC input loads 380V Adapter 48V What keeps power people up at night? Upgraded Equipment: Bus Converter Retrofit What keeps power people up at night? New Equipment: Factorized Power Architecture What keeps power people up at night? System Efficiency Summary Expected “source to typical server CPU load” peak efficiency of the three considered architectures, with power sourced from rectifier (380 V) and energy backup (260 V ETSI minimum) blocks respectively Power System Architecture Source Backplane High Voltage distribution IBC Equalizer Standard IBC Motherboard distribution ZVS-BB SAC NiPOL Total HV rectifier 99.7% 97.0% 99.2% 98.0% 99.0% 90.0% 83.8% Backup 99.2% 95.0% 97.0% 98.0% 99.0% 90.0% 79.8% HV rectifier 99.7% 95.5% 97.5% 90.0% 83.5% Backup 99.2% 93.0% 97.0% 90.0% 80.5% HV rectifier 99.7% 97.0% 99.0% 97.5% 94.0% 87.7% Backup 99.2% 95.0% 99.0% 96.0% 94.0% 84.2% Adapters Upgraded server cards Factorized Power What keeps power people up at night? Verification and Validation A small scale, live demonstration system has been built in order to verify the proposed power architectures as well as validate the expected performance PLACE YOUR LOGO HERE What keeps power people up at night? Block Diagram of Small-scale Model Small-scale, live demonstration of 400V DC distribution powering typical telecom datacenter loads What keeps power people up at night? Small-scale Live Demonstration System LED monitor Emerson Network Power AC-DC Converter VICOR reference design for Intel VR12 CPUs VICOR Demonstration Board LED lighting fixture 1U Server WLAN Switch Industrial PC What keeps power people up at night? Demonstration Board Enabling the Three Proposed Power Architectures • HV Rectifier: Emerson Network Power R400-15000e • 1:8 HV IBC: Vicor 384 V to 48 V BCM • 1:32 HV IBC : Vicor 384 V to 12 V BCM • Equalizer ZVS-BB: Vicor 500 W full size PRM coupled with Picor PI2127 used as active bypass element • EMI filter: discrete What keeps power people up at night? How Equalizer Circuit Works – Compliance to ETSI EN 300 132-3-1 External OR-ing bypass implementation: equalizing function waveforms Equalizer regulation with rising high voltage bus, no load (C1: high voltage input; C2: IBC K=1/8 output voltage; C3: equalizer output voltage; C4: load current) Equalizer regulation with falling high voltage bus, 500W load (C1: high voltage input; C2: IBC K=1/8 output voltage; C3: equalizer output voltage; C4: load current) The active OR-ing provides direct input to output connection of the equalizer block whenever the regulation function isn’t needed. What keeps power people up at night? Efficiency Results Interface board input voltage Max Power Peak efficiency Power at peak efficiency [V] [W] [%] [W] HV IBC, K=1/8 380 1000 97.0% 570 HV IBC, K=1/32 380 300 95.5% 220 ZVS-BB Equalizer, by-pass 380 N/A 99.2% N/A ZVS-BB Equalizer, working 260 800 97.0% 700 Interface board block The experimental system accurately represents the proposed architecture, but the various converters do not exactly match in terms of power capability. If the various power components were arranged such to work close to their peak efficiency it would be possible to match the expected efficiency values previously listed. What keeps power people up at night? Facility Transition Paths as Seen From the Experts Source: Didier Marquet, France Telecom - Orange Labs What keeps power people up at night? Conclusions • Power systems architectures suitable for 400 V DC distribution have been proposed and analyzed. • Synergy between high voltage bus converter and Voltage Equalizer has been proven to be key enabler for 400V DC distribution systems. • An experimental system was built and characterized, in order to validate the theoretical analysis. • Performed tests confirm operation over the wide voltage range specified by ETSI EN 300 132-3-1 standard (260 V DC – 400 V DC) at expected high efficiency. What keeps power people up at night?