Analysis of Distribution Capacitor Switching Transients

Project Summary:

Capacitor bank switching is one of the most common switching events on electrical power systems. Capacitors are quite economical and are generally a convenient means of providing reactive power compensation to correct power factor and support voltage. This makes them prevalent in mots U.S. power systems. When energized, a capacitor bank can interact with the system inductance to yield oscillatory transients which can propagate into the local power system and pass through distribution transformers into customer loads and facilities. Under specific circumstances, these transients may cause misoperations or even damage equipment at customer facilities.

The primary objective of this project is to define and quantify, through use of detailed computer simulations, the key factors which affect capacitor switching transients, with respect to their magnitude and frequency, on distribution systems.

The approach of the study involved three main tasks:

  • Developing an EMTP-RV model of a real-world distribution system to be used as a test system,
  • Performing a parametric study to determine the sensitivity of switching transients on a number of different parameters, and
  • Developing general rules for distribution engineers to help them with capacitor placement to minimize switching transients.

An additional task reviewed the impact of capacitor switching transients on nearby reclosers.

Table of Contents:


Who Should Use:

Distribution Planners, Standards Engineers, Power Quality and Reliability Engineers

This study was conducted in P16-7