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Schweitzer Engineering Laboratories has released the SEL-421 Protection, Automation, and Control System with enhanced Time-Domain Link (TiDL) technology. TiDL is a protection-centered digital secondary system that replaces secondary system copper connections with fiber to decrease costs and increase safety. Its enhanced features include a purpose-built merging unit, data-sharing capabilities and modern configuration software.

As part of its normal functionality, the SEL-421 protects critical transmission lines with high-speed distance and directional elements. In addition, its subcycle distance elements and series compensation logic help reduce operating times and improve system stability.

In a TiDL system, an SEL-421 in the substation control house is connected via fiber to an SEL-TMU TiDL Merging Unit located in the yard. The merging unit samples and digitizes analog values from primary equipment and then directly transmits those data via a non-Ethernet protocol to as many as four SEL TiDL relays.

TiDL’s point-to-point architecture and data-sharing capabilities provide application flexibility and strong cybersecurity. In addition, because TiDL does not require Ethernet switches, routers or external time sources, it is simple to implement. SEL Grid Configurator software, which is available with the enhanced TiDL relays, makes configuring and commissioning devices and custom topologies to fit each application easier too. Visit the Support Videos webpage to learn how to configure TiDL devices using Grid Configurator.

Soon, the SEL-411L Advanced Line Differential Protection, Automation, and Control System will release with TiDL and SEL Sampled Values technology. For information on its release date, contact Lead Product Manager Scott Wenke.

To learn more about TiDL technology, visit the solutions webpage.