Why is internet icon Google concerned with energy efficiency? It turns out that the cooling systems on the roofs of Google’s facilities in The Dalles, OR are so large they can be seen for miles. Server farms, such as those of Google, Microsoft, Yahoo and others, are infamous for their power consumption. According to a recent report by Jonathan G. Koomey, Ph.D., a staff scientist at Lawrence Berkeley National Lab. and consulting professor at Stanford University, server farms take the entire capacity output of the equivalent of five 1000-MW power plants in the U.S. alone.
Consequently, Google is interested in energy-efficient power supplies. So was the record number of attendees at the 2008 Applied Power Electronics Conference (APEC). With plenary session speakers who gave the big picture and technical papers that dug into the details, energy efficiency topics included: digital power supplies, LED lighting, energy harvesting and more. Industry analyst Mohan Mankikar noted that “energy efficiency is now a high profile issue.”
Digital power management was such a visible element of this previously analog-only event that Brian Narveson, power marketing development manager of Texas Instruments raised the question, “Will your next major power supply provider be a software company?”
There is no doubt that software is creeping into power supplies. With 10 integrated circuit suppliers of the current 38 Power Management Bus (PMBus) adapters present at the conference, the PMBus protocol for digital power management was difficult to miss. The specification allows products from different suppliers to provide common communication data and control power subsystems. The PMBus Implementers Forum introduced version 1.1 of the PMBus protocol that has new commands for controlling ac-to-dc power supplies.
Switching Power Supply
If you have trouble relating to a switching power supply, Power Integrations provided a visually intriguing mechanical analogy. Designed by sculptor, Karl Lautman, the Kinetic Art Sculpture uses a motor, camshafts, gears, clutches, levers and magnets to show the voltage signal’s transition and the impact of various components in a switching power supply. For real world applications, Power Integrations 10 W DPA422 switching power supply enables engineers to develop efficient power supplies for Power Over Ethernet (PoE) applications such as VoIP telephones.
Cool Chips: Silicon Carbide Schottky Rectifier
Cree, Inc. introduced a 50-amp Zero Recovery silicon carbide (SiC) Schottky rectifier chip with a maximum operating voltage of 1200V. The new CPW2-1200S050 significantly improves the efficiency in power inverters in applications such as solar and wind power converters, industrial motor drives and electric vehicles.
To cope with the heat that is generated even in the most efficient power conversion, Amulaire developed a cold plate for a liquid-cooling system for a 100 kW motor drive for hybrid vehicles. Rinehart Motion Systems LLC motor drive is half the volume of comparable motor drives thanks in part to the cold plate and other inverter improvements.
APEC Videos and More
Power supply engineers may not be rock stars but they do provide great information as Darnell Research Power Pulse Daily’s video coverage of APEC 2007 demonstrates. Two examples videos are the introduction of the National Semiconductor’s LM5116 synchronous buck controller and Texas Instruments’ power management products including the UCC28600 PFC Controller and other demos. You may also view other videos at Power Pulse's website.
Download APEC’s special presentations
In Amulaire's cold plate, the evenly distributed flow pattern around the pin fins achieves velocities over 3 m/s.