VERIFICATION

A one-way paging system provides the means of control to the CBCs. The imported station feeder metering verifies the status of successful operations. The CBCs can support two paging frequencies. If a CBC doesn't detect a “heartbeat” on a channel for 30 minutes, it will fail over to the alternate frequency. This feature allows the system to stay on-line, even if a hardware issue prevents communication on one of the redundant paging companies. The CBCs also feature local high- and low-voltage rail settings to maintain proper line voltage in the absence of any remote commands.

To help ensure capacitor bank issues are addressed as soon as they occur, routine verification schedules are run. A nightly schedule is run to verify capacitor banks that have failed during the day. A weekly schedule is run to verify the status of all capacitor banks on a substation bus. Information regarding failed or questionable banks is automatically e-mailed to BGE's Automation & Technology unit and scheduled for maintenance.

TIME AND COST SAVINGS

Because the algorithm in the Yukon software depends on fixed values that determine the voltage to load curve, BGE's IT department was able to create an import program that is used twice a year to change the curves based on the summer and winter loads. This saves time and travel to the substation to load seasonal changes into station equipment by hand.

The system has reduced the amount of space required to house substation equipment, eliminated the need to install and wire new equipment, and resulted in a savings in capital construction for new substations. BGE saves an estimated US$25,000 in construction costs per substation and a total estimated $12,000 in labor repair costs per year using the new centralized control system.

Since mid-2006, 24 BGE substations have been transferred to the centralized capacitor control system. There were some initial issues, one regarding paging latency during busy periods and another involving spam filtering at the paging vendors, which caused failed operations. However, most issues were not major and have been resolved.

Overall, the centralized approach offers many benefits and has been successful in realizing a savings in daily operations and installation. This approach also has enabled a live system view and control to various entities within the organization, reduced substation equipment maintenance and eliminated travel to substations for seasonal curve changes.

Michael S. Smith is a senior engineering analyst with Baltimore Gas and Electric's Automation & Technology unit. With 25 years experience in the utility business, Smith specializes in system protection, performing maintenance, and substation commissioning and integration. michael.s.smith@bge.com