ENERCON upgrades nuclear facility's protection system with digital relays

ENERCON’s Electrical Analysis Group (EAG) supported a design change package for upgrading the generation protection system at a two-unit U.S. Boiling Water Reactor nuclear facility. The project involved replacing outdated electromechanical relays with modern digital/microprocessor-based relays to improve protection for the main generator, main transformer, and unit auxiliary transformers. The following protective functions were included in the protective relay replacement:   Phase overcurrent  Neutral ground overcurrent  Negative sequence  Back-up distance protection with supervision  Volt/Hz protection  Differential protection  Overvoltage  Reverse power  Loss-of-excitation  Underfrequency protection The electromechanical relays were replaced with Schweitzer SEL-400G, SEL-487E, and SEL-787-4X relays. As part of the upgrade, the EAG team also performed new protection setting calculations for the main generator, main transformer, and each unit auxiliary transformer. These calculations adhered to IEEE and NERC standards (PRC-19, PRC-24, PRC-25, and PRC-27), and incorporated recommendations from equipment and relay manuals. In addition to updating the protection settings, the team enhanced documentation to support future maintenance and understanding of the system. Relay settings were created using SEL’s acSELerator QuickSet software, which included the set-up of the relay, display points, sequence of event recorder, fault event recorder, relay setpoints, and I/O logic. The SEL-400G units were also programmed with customized pushbutton locks and group selection controls to facilitate operator actions to move to different plant alignments. To support implementation, our EAG team developed detailed relay test procedures. This consisted of the device test points (e.g. overcurrent, distance), time delay settings, input permissive, and output logic testing to validate proper operation of the relays to meet NERC PRC-002 testing requirements. The team also provided on-site field support during testing and commissioning to troubleshoot and resolve any issues. This project hallmarks the commitment from the nuclear industry to modernize their analog equipment. ENERCON supported a successful design retrofit and smooth implementation which shows the industry can rely on us to bring the nuclear power industry into the modern era. Our dedicated teams are Engineering America’s Energy Transition for secure and more resilient energy infrastructure. Contact us today to learn how ENERCON’s experienced engineers can design system upgrades and retrofits for you. #NuclearEnergy #Grid #PowerDelivery #Engineering https://lnkd.in/eTjmyEwz