Utilities Improve Reliability of Underground Distribution Systems
Utilities are hardening their distribution systems to become more reliable. To do this, many are moving their aboveground systems to underground vaults to protect transformers and other components from damaging weather. Other utilities, such as American Electric Power (AEP) and Public Service Electric and Gas Company (PSE&G), are modernizing their existing underground systems to make field data visible and actionable. By deploying fiber optics and monitoring and control technologies, AEP and PSE&G have remote insight into their systems and the benefit of being more automated, reliable, proactive, and safe.
AEP and PSE&G modernized their distribution system by deploying fiber and smart technologies including:
- Sensors monitor the transformer, network, and the vault for factors like transformer temperature and oil level, power flow, and fire or flood conditions.
- Remote Terminal Units (RTU) installed in the vault process signals from physical field sensors into digital messages and allow for remote control of connected assets like network protector relay and transformers.
- Redundant high-speed, fault-tolerant fiber communications transmit the monitoring and control inputs and commands through the RTU.
- SCADA organizes real-time data that is displayed on easy-to-read dashboards via the Distribution Management System (DMS) at the operations center. A Historian system logs data and creates trends that help utility operations, engineering, and maintenance predict equipment health.
As a full-service engineering, design, and construction firm, Black & Veatch was able to customize services to best meet the needs of each utility. Black & Veatch worked with AEP to provide the design and installation of the system. For PSE&G, Black & Veatch programmed SCADA and managed project installation.
PSE&G: 258 RTUs and 543 transformers installed across 5 networks in New Jersey.
AEP: 306 RTUs and 1,188 transformers installed in networks that spanned 7 states.
Automation. With greater visibility and remote control of their systems, AEP and PSE&G quickly identify the location of impending faults and failed equipment, avoiding hours of randomly pumping manholes. As a result, work crews operate with efficiency and precision. They isolate issues faster and remotely remove transformers and reroute power flow to stay online.
Safety. Using sensor data, crews understand vault conditions before they enter, avoiding hazards like fire and flood. AEP engineers use tablets to access the network, which means they are connected, aware, and able to adjust operations from the safety of their vehicle or operations center. These smart systems also protect the public by reducing the potential for fires in the underground network. Through modernization, the utilities constantly monitor transformer cable health, power flow, pressure, and temperature, which reduces the risk of overheating and potential explosions underneath city streets and neighborhoods.
Reliability. Real-time asset management enables AEP and PSE&G to maximize the efficiency and reliability of their system. Low temperature readings from sensors indicate which lines can accept more load, and low oil levels in transformers signal replacement. These insights inform maintenance schedules and operational adjustments for optimal performance. PSE&G followed Black & Veatch’s recommendation and used military-grade connectors and potting seals to waterproof vault components. Soon after, Hurricane Sandy roared ashore putting New Jersey under 20 feet of water. While PSE&G’s vaults flooded, the vault components did not leak. The transformers and monitoring and control system stayed fully operational with no damage or failure.
“Black & Veatch did an exceptional job of understanding our needs, templating out the displays and building them, and providing ‘visibility’ to our operators. We found their team to be adaptable to changing conditions and extremely qualified.” – Richard Wernsing, Manager of Electric Asset Reliability, Public Service Electric and Gas Company.