by Gene Wolf
The Tennessee Valley Authority (TVA), the DOE and Smart Wire Grid Inc. deployed an array of 99 SWG distributed series reactance units on one of TVA’s 161-kV transmission lines. The units provide sensing and monitoring of the line and, when needed, can inject inductive reactance to improve power flow (see T&D World April 2013 for more details).
A Different Grid
The industry now has the ability to determine a transmission or distribution line’s rating in real time by remotely monitoring certain mechanical and thermal characteristics of the line. Thanks to advancements in sensor technology and the maturing of smart grid applications, the benefits of dynamic overhead line ratings are being experienced throughout the industry. They are allowing utilities to reduce or defer capital expenditures, improve congestion and push more power to the customer.
Initial real-time monitoring results show dynamic rating improvements ranging anywhere from 5% to 20% over static line ratings. This is a huge improvement for the transmission-constrained grid, especially considering this capacity can be added without any public hearings, regulatory approval or system outages.