Protection, Automation, and Control Merging Unit

Apply the SEL-401 Protection, Automation, and Control Merging Unit for substations with IEC 61850-9-2 Sampled Values (SV) systems. Sample analog data, such as currents and voltages, then publish those data to a fiber-based Ethernet network for use in other IEDs, such as compliant SEL-400 series relays. The SEL-401 publishes SV data to the process bus network and also provides local protection. Use the built-in phase-overcurrent and breaker failure protection to provide backup in case of communications system failures.

Applications

IEC 61850-9-2 SV Implementation—Place the SEL-401 out in the yard right next to primary equipment. The SEL-401 digitizes analog signals from primary equipment and then transmits them to the control house via a fiber-based Ethernet network. It can publish as many as seven outgoing data streams of IEC 61850-9-2 SV data to any relays that subscribe to SV. The merging unit can synchronize the data using the IEEE 1588 Precision Time Protocol Version 2 (PTPv2) or an IRIG-B time input.

Integrated Protection—Provide local breaker failure and phase overcurrent protection during a loss of the precise time signal or communication to a main substation relay. The SEL-401 uses high-speed (5/8-cycle) open-pole detection logic to reduce coordination times for critical breaker failure applications.

Dual-Breaker Schemes—Accommodate two sets of three-phase currents and two sets of three-phase voltages to support substations with dual-breaker schemes. You can combine currents within the merging unit from two sets of CTs for protection functions but keep them separately available for monitoring and station integration applications.

Oscillography—Record voltages, currents, and internal logic points at up to an 8 kHz sampling rate. Phasor and harmonic analysis features allow the investigation of merging unit and system performance.

Sequential Events Recorder (SER)—Record the last 1,000 entries, including setting changes, when the merging unit turns on, and selectable logic element operations.