UPS applications: a mill perspective

This article results from the experience of installing a number of uninterruptible power supply (UPS) systems for various projects. It attempts to describe typical applications in a pulp and paper mill, determines how to evaluate whether a UPS system should be used, and suggests some alternative approaches to the problem. There are several types of UPS configurations available. Although rotating types are extensively used, the static type is more prevalent and is the basis for most of the discussion. Many applications have potential problems with power quality and availability. Factors are listed that will help determine whether a UPS system should be installed. Typical applications in pulp and paper mills are listed and discussed. Problems from some actual installations are described and alternative approaches are examined. Power quality and availability is a design consideration that requires careful attention to achieve the desired result. It will be more important in the future as utility power systems become less reliable