Best Practices for Storm Response - DistribuTech 2010 Presentation

In 2009, the DSTAR consortium commissioned a study of the best practices for utility storm response. The study examined the practices, procedures and experiences of U.S. utilities during major storm occurrences with the goal of understanding and conveying what went right and what went wrong during the build-up, restoration and ramp-down phases. The investigation included detailed utility surveys, interviews with storm bosses, vendors and consultants, and reviews of reports, proceedings, and papers. The result is comprehensive discussion of many important aspects of storm restoration with an emphasis on best practices and lessons-learned from past experiences.

This presentation summarizes some discussion items and key findings from the study, particularly revealing cases, and recommendations from utility experiences.


DSTAR Overview

Short Overview of DSTAR
Who We Are; What Distinguishes US; Where Do We Fit; Consortium Structure; Research Areas; Program Content; Selected Project Descriptions.


Surge Protection of Electronic Controllers for Overhead Distribution Feeder Capacitor Banks

Utilities have installed many electronic devices (IEDs) to enable safe, reliable, and efficient operation of the distribution system. These IEDs include controllers for overhead feeder capacitor banks. Some utilities have reported controller failures due to power surges and overvoltage events.

This presentation is based on Project 14-4: Surge Protection of Electronic Capacitor Controllers in Distribution Systems. It summarizes an investigation by which controller installations at several utilities were simulated in the Alternative Transient Program (ATP) to quantify the surge voltage and currents on the distribution circuit as well as on the controller circuits. The controller is powered via the control power transformer (CPT) which reduces the feeder voltage (typically 15, 25, or 35 kV) to 120 V. The impact of surge arresters at the CPT and/or the controller were investigated relative to surge voltages at the controller.

In addition, the impact of transformer and controller ground connections were also investigated. To improve quality of the CPT model, several frequency scans were performed on a 0.5 kVA CPT from which a terminal model was synthesized for the ATP model. From the parametric analysis, several recommendations for CPT and controller grounding as well as surge arrester placement were developed.