Power Quality Solutions to Mitigate the Impact of Voltage Sags in Manufacturing Facilities

摘要

The dominant power quality problems in industrial manufacturing applications are short duration voltage sags and momentary interruptions. For 'normal' grid customers, the EPRI Distribution Power Quality study clearly demonstrated that the vast majority of power line disturbances are of short duration. For customers connected to 'premium' grids, realized with dual independent distribution feeds with high-speed make-before-break ATS systems, connection to transmission grids, or use of highly meshed grids, short duration voltage sags represent essentially 100 percent of the power disturbances they experience. Power quality solutions, which protect against all short duration power line disturbances, provide protection against virtually 100 percent of all the events experienced by those customers who have the highest cost of downtime, the 'premium' grid customers. With the increasing demands for minimizing downtime in manufacturing operations, facilities managers have been challenged to identify cost-effective solutions to address power quality related problems. This article will provide an overview of the power protection issues faced by industrial facilities, based on a review of utility PQ problems, typical plant power distribution systems, and sensitivity of various equipment and processes. Select applications' experience of power electronics-based PQ solutions, such as the Dynamic Sag Corrector~(~R) (DySC~(~R)―pronounced 'disk'), in critical manufacturing operations will be presented. The selection criteria will be highlighted to demonstrate how the solu- tion configuration, rating and placement within a facility impacts its economic viability. The pros and cons of 'facility wide' versus 'point of use protection' will be discussed. Finally, the issues related to ROI for manufacturing processes will be discussed.