Surge Protection of Electronically-Controlled Devices Installed in Distribution Systems
One of the ways that utilities have improved the performance and efficiency of the distribution system is by installing equipment-based electronic controllers throughout the distribution system. Examples of these controllers include ones used with voltage regulators, reclosers, sectionalizers, tap changers, and overhead feeder capacitor banks. As the number of controller installations has increased, several DSTAR utilities have experienced more controller failures than expected. In particular, overhead feeder capacitor controllers were identified for study in this project and focused on controller failures attributed to lightning.
Using pole installation diagrams of capacitor bank controllers provided by several DSTAR members, the pole installations are simulated in the Alternate Transients Program (ATP). Local lightning strikes are simulated to determine the factors which affect the transient voltages at the controller.
The study report makes recommendation based on a parametric study of both actual DSTAR member pole installations as well as variations of these installations and corresponding observations.