The process of supplying power to end-use equipment always includes determining the most efficient and reliable power-system design. There are endless ways to transform, convert, correct, and protect power from the utility supply to the demand-side use — all requiring cost consideration. So what's the optimal approach? Generally, you should avoid or minimize the above measures throughout the delivery system, then provide what's needed at the equipment. Aron Levy reminded me of this design fundamental in his November article on power supply system integration-battery backup.
In that article, Levy discusses dc UPS systems (DUPS) and the advantages of embedded systems. “This approach pays well at the end in a more efficient, less costly, and far more reliable system for the end user,” he writes. This statement drives home the point that inherent advantages exist in managing the supplied power at the equipment location, although embedded applications are not always the best solution.
From a power delivery viewpoint, the efficiency advantages of embedded applications are obvious. The less you transform or convert power, the more you avoid the losses associated with these processes. The same holds true for power compensation and correction. With any of these required measures, efficiency is gained when they're performed closer to the equipment.
Reliability measures are also best implemented at the end-use equipment. The goal is to provide a continuous efficient power source to operating devices. With embedded systems, you can avoid redundant measures, eliminate compatibility concerns, and minimize exposure to adverse environmental conditions.
The performance advantage of managing supplied power at the device level seems apparent. Why then, don't more manufacturers equip their products with this capability? Levy asserts that the embedded approach (DUPS) is less costly than other add-on UPS methods for large systems in the multi-kW range. We have seen the increased capability trend of smart devices. Will designers and integrators migrate toward embedded applications? Please respond with your thoughts and/or comments to [email protected].