Distribution Sectionalizing and System Protection Studies

Utility electric distribution systems are sectionalized, which protects them from damaging fault currents by a variety of different protective devices installed across the system. These sectionalizing devices are also paramount in ensuring public safety in the event of a downed conductor or contact with an energized line. Over time, changes to the sectionalizing equipment are required in various locations as a result of new construction and line changes, system configuration changes, and increased fault current levels resulting from substation transformer and transmission line upgrades.

To ensure proper protection of your system, each device must be periodically reviewed to evaluate its ability to:

• Sense the minimum fault current in its zone of protection.

• Interrupt the maximum fault at its current location.

• Adequately handle continuous load currents during peak conditions and emergency backfeeding configurations.

• Coordinate with upstream and downstream devices.

The Power System Engineering, Inc. (PSE) team of professionals has many years of experience working with utilities in the area of sectionalizing and system protection. PSE can lead or assist your utility with:

• Evaluating sectionalizing equipment and making recommendations for change where problems are found and where system improvements are being made.

• Verifying size, type, and recloser settings that are re-installed during maintenance schedules.

• Assisting with programming of new and existing devices to accommodate current protection requirements.