Wide area power quality-decision processes and options for sensitive users

The complexity surrounding solutions to power quality problems, faced by customers and utilities alike, is the subject of the paper which explores the decision process needed to evaluate the optimum solution to power quality, and examines the options available. Modern production equipment increasingly needs some form of external protection to prevent damage or shut-down during supply disturbances. The results and discussion of the power quality survey presented suggests voltage dips are the prime cause of supply related downtime. Defining compatibility levels between supply and equipment is a difficult process which is usually left to the user who frequently lacks the information necessary to reach a satisfactory decision. The utility does have a role to play in this determination by aiding customer understanding and supporting the decision process. However the decision ultimately must be made by the customer who must fully understand the true costs of downtime. For large users, wide area protection of supplies, that, in particular, decrease sensitivity to voltage dips may provide the simplest solution to large scale users, while providing minimum impact on surrounding distribution networks.