Quality of Electric Power

Defects in the quality of electric power supplied to modem loads such as computers and logic-control systems produce expensive and dangerous errors and failures. Defects can be categorized by magnitude and time duration, but information on occurrence in typical utility systems is lacking and quantitive means for description must be developed. The impact on critical loads can be reduced by improvements in utility system design, by increasing the load equipment tolerance, and by using rotating and static standby units between the source and the load.