Case Study: LG&E and KU modernize Kentucky distribution systems with SEL

Distribution Modernization in Kentucky

Louisville Gas and Electric Company (LG&E) and Kentucky Utilities Company (KU) needed to modernize aging substation and distribution infrastructure across a large service territory while maintaining reliability for more than 1.3 million customers. Their legacy electromechanical relays lacked the communications and automation capabilities needed to support centralized grid operations, expanded SCADA visibility, and improved fault isolation, so they partnered with Schweitzer Engineering Laboratories (SEL) for design and commissioning support.

SEL implemented a standardized retrofit program using SEL-351S protection systems, SEL-751 feeder relays, SEL-387E transformer protection, SEL-3555 RTACs, SEL ICON networking, and SEL-3620/3622 security gateways, with cellular communications added in rural areas. The work replaced more than 3,800 electromechanical relays, targeted 495 distribution feeders and 460 circuit breakers, and increased rural SCADA coverage to 74% of customers. LG&E and KU reported improved system visibility, automated power restoration, and a smoother outage process, with some upgrades completed within a Monday-to-Friday outage window.

Louisville Gas and Electric Company (Lg&e) and Kentucky Utilities Company (Ku)

Josh Neely

Group Leader of Substation Protection and Control