S&C’s No-Outage System Gaining Popularity Among Major Utilities.

To make room for an airport expansion, an existing convention center needs to move to a new location approximately 3 miles away. But could anyone actually move a convention center? Not likely. Instead, developers plan to build a new one, along with new hotels, office complexes, and retail establishments to accommodate forecasted growth in the area. This new neighborhood, a 5-year development project, will demand very reliable electric power service, since any disturbance could result in lost reservations, customer walkouts, lost sales, lost data — lost money. So the question was, “How do we design the most reliable distribution system to feed our power-critical customers?” S&C provided the answer.

The highly successful “no outage” system that S&C engineered to serve Florida Power Corp.’s critical customers on International Drive in Orlando, Fla., offered a model for a possible solution. S&C’s Power Systems Services was contracted to perform a feasibility study for implementing a similar High-Reliability Distribution System (HRDS) for the new convention center and surrounding neighborhood.

The forecasted load growth in the area requires an expandable and economical system design — a perfect fit for S&C’s HRDS. From the SCADA system to the underground-distribution cables, equipment must be specially designed to meet system demands and customer requirements.

Specific design criteria include:

Automatic sectionalizing of a faulted feeder cable on the underground loop system while providing uninterrupted service to the other loads in the system.
The distribution system should have high-speed fault clearing on the underground loop system after a first-contingency event. Second-contingency events, however, may need operator intervention to recover.
Any single failure should be isolated automatically and service should be restored to as much of the load in as short a time as possible.
The system should accommodate loop loading due to the loss of a feeder exit cable with no further reconfiguration necessary.
Remaining system load capacity should be equalized as much as practicable throughout the distribution system.

Albeit not an electrical design criteria, cost-saving opportunities were given consideration and targeted primarily in construction-cost minimization — a “vision for the future” approach was required.

As the innovator of the High-Reliability Distribution System, S&C is now charged with customizing the HRDS to meet the specific system requirements and operational needs for yet another utility serving critical customers.

Want to know more? Learn how S&C designed the High-Reliability Distribution System with a “vision for the future.” Also check out the article from the April 2000 issue of Transmission and Distribution World magazine.