Battery Power - Spring 2016 - (Page 6)

Feature Reducing TCO with the Right UPS Architecture and Operating Mode Peter Panfil, Vice President, Global Power * Emerson Network Power One of the most widely discussed issues throughout the world today is the rapidly increasing demand for energy within the computing industry. This is fueling interest in energy efficiency solutions worldwide. Many organizations are looking at their data center's UPS systems to optimize efficiency while protecting availability and maintaining flexibility to quickly meet growing demands. This article looks at two steps data centers can take with their power infrastructure to achieve that optimal performance. The combination of these two suggestions, utilizing a high-energy efficiency mode and moving to a reserve bus power system configuration, when done correctly with the appropriate considerations and planning, can help to significantly reduce total costs. High-Energy Efficiency Mode Many data center professionals are turning to some form of economization in an effort to increase efficiency. Today's high-availability, double-conversion UPS systems can achieve efficiency improvements through the use of active eco-mode. This mode of operation accomplishes improved efficiency by powering the bulk of the critical load through the bypass path. When power problems are detected, the UPS automatically switches back to double-conversion mode. In double-conversion UPS systems (Figure 1), the rectifier and inverter should be designed to run continuously with the rectifier directly powering the inverter. The incoming AC is rectified to DC, which is then converted back to AC by the UPS inverter, resulting in a low-distortion, regulated stable AC output voltage waveform. This process can be up to 97 percent efficient. Approximately three to six percent of the energy passing through a double-conversion UPS is lost in the conversion process. Traditionally, this has been accepted as a reasonable price to pay for the protection provided by the UPS system. Figure 1. Double conversion mode is the most widely deployed UPS topology in mission-critical data center applications. The active eco-mode approach (Figure 2) pushes efficiency up above 97 percent in some cases. It keeps the inverter and rectifier in an active state, which means the inverter is providing output that matches the bypass and is ready to accept the load immediately. As a result, the transfer to the inverter can be accomplished almost seamlessly. When the UPS senses bypass power quality falling outside accepted levels, the bypass opens and transfers power immediately back to the inverter until bypass anomalies are corrected. Once bypass power anomalies end, the critical load returns to active eco-mode automatically. Figure 2. Active eco-mode offers a more seamless transfer and possible UPS efficiency in excess of 97 percent. 6 Battery Power * Spring 2016 www.BatteryPowerOnline.com http://www.BatteryPowerOnline.com

Table of Contents for the Digital Edition of Battery Power - Spring 2016

Editor's Choice
Reducing TCO with the Right UPS Architecture and Operating Mode
Decades of Data: Using Analytics to Predict the Future
Top Four Considerations for Battery Management in a Connected World
Conference Preview
Designing and Managing Custom Battery Pack Plastic Enclosures
Assessment of Performance and Safety on Lithium Ion Pouch Battery Under Various Test Conditions
Batteries
ICs & Semiconductors
Charging & Testing
Industry News
Calendar of Events

Battery Power - Spring 2016