Rules-based algorithm for detecting transient overvoltages due to capacitor switching and statistical analysis of capacitor switching in distribution systems

Numerous power providers and electric power end-users presently monitor their systems with specialized power quality monitoring instruments. These monitors employ different triggering algorithms for capturing variations in power quality. Due to their simple design, the algorithms will capture many measurements, with only a subset representing transient overvoltages due to capacitor switching. The power providers and end-users performing this monitoring have need of quickly and efficiently identifying this capacitor switching subset without manually analyzing individually the many other disturbances. This paper explores the application of a rules-based algorithm for identifying capacitor switching transients in a monitoring project conducted on 24 utility systems across the United States. Statistical analysis on the identified transient overvoltages is also presented, with particular focus on the peak magnitude of the transient, event duration, principal switching frequency, and hour of day of occurrence.