Several companies addressed various aspects of 380Vdc microgrids at this year’s Techno Frontier. Bellnix pre-announced a new 380Vdc power system targeted at data centers. TDK-Lambda was previewing a new bi-directional dc-dc converter designed to interface between 380Vdc micro grids and 48-Vdc battery storage systems. Aval Nagasaki Corp. was demonstrating its “Smart Power Solution” for HVDC microgrids in homes and commercial buildings. And Furukawa Power Components Inc. was showing a 380Vdc connector it jointly developed with NTT Facilities for use in data centers, telecommunications installations and dc microgrids.
In a prominent location in the exhibit hall, Bellnix was previewing what it believes will be the next-generation of data center power. Called “Fresh HVDC” the new rack-mount dc-dc converters combine the benefits of 380Vdc distribution (fewer conversion steps, lower distribution currents, and so on) and the efficiency gains from using SiC power silicon to produce a system that delivers 97% efficiency at 50% load. Model BHVD380-12S180 produces an output of 12Vdc at 180A.
In a standard 19-inch rack three of these 1U high, 2.2kW units can be operated in parallel to provide n+1 redundancy or up to 6kW of total output power. The inclusion of PMBus capability enables several features including the ability to turn the output voltage ON or OFF without cycling the input power, as well as monitoring several parameters such as output voltage and current, internal temperature, fan rotation speed, cumulative operation time, and so on. In addition, capacitor lifetime predictions are possible using the internal temperature monitoring capability.
A short distance from Bellnix, TDK-Lambda was demonstrating the capabilities of the EZA series of isolated bi-directional converters. These advanced dc-dc converters employ digital technology to change the control loop parameters and optimize operation depending on the direction of the energy transfer, ensuring at least 94% efficiency in both directions. In battery charging mode, the output voltage is 48Vdc (36-60Vdc) and the input voltage from the dc microgrid is 320Vdc nominal (300-380Vdc). In discharge mode, the input and output voltages are reversed.
Rated for 2.5kW, the 1U-high, full rack wide EZA2500-32048 is capable of autonomous operation and can automatically change conversion direction to stabilize input or output voltage. Automatic and seamless switching between charge and discharge within 15ms (typical) is accomplished by optimizing the design of transformer and the use of both synchronous rectification and digital control technology and makes it possible to use these dc-dc converters to stabilize the dc bus voltage in HVDC microgrids.
External devices can control and monitor the status of current, voltage and conversion direction through the RS485 serial communication port. These dc-dc converters feature two operational modes: Self commutating mode autonomously stabilizes the voltage of the HVDC microgrid and determines the conversion direction. In external control mode the units accept external commands that dictate the conversion direction.
In the Smart Home Consortium pavilion, Aval Nagasaki was showing its line of “smart power” ac-dc power supplies and dc-dc converters that include LinuxOS, LAN interface and a CAN bus. The ac-dc converters are bi-directional to integrate the 380Vdc high-voltage bus with the utility power grid. Rated from 1.2 to 5kW, these power converters are part of a comprehensive system that includes dc-dc converters with MPPT capability for integrating PV panels or wind turbines with the microgrid, bi-directional dc-dc converters to integrate battery energy storage (e.g. bi-directional 380Vdc to 48Vdc) and EV charging/discharging capability, and the “Smart Power Manager” to monitor and control the various system elements.
SPM-1000 Smart Power Manager is designed to integrate renewable energy sources such as PV with storage batteries and to optimize the performance and efficiency of the microgrid. The unit is equipped with network communication capabilities, and an external sensor input. It can operate in automatic mode or under manual control such as remote control via internal Web applications.
Furukawa Power Components Inc. was demonstrating a connector for 380Vdc systems that was jointly developed with and NTT Facilities, Inc. According to the companies, HVDC power supply systems are the next-generation power supply system expected to help conserve energy at telecommunication buildings and data centers. The product may be applied not only to HVDC power supply systems but also to solar, wind, and other natural power generation and also to areas involving the Smart Grid.
The new connector provides an alternative to HVDC connectors already offered by Anderson Power Products and Fujitsu Components. It includes a “keying” interface to prevent miss-insertion of improperly polarized connectors. The structure ensures safety by embedding the connector interface deeply within the connector structure and it can be installed without the need for special tools or crimpers.