Causes of Voltage Dips on AC Power Systems

摘要

An independent voltage sag study was conducted in March 1997 to investigate the quality of power supplied by WAPDA to a group of medium industrial customers in District Gujranwala, Pakistan. Utility and facility data was analyzed on engineering judgement basis and results were verified by computer simulation. The analysis was based on existing data for the previous few years. Based on customers voltage dip record, the events were related to utility (WAPDA) faults history. Most of the severe disruptive voltage dips were found to occur at the same time when the faults occurred on utility distribution or transmission network.