SEL-400G

The SEL-400G is a next-generation generator protection system designed for medium to large power generating units. It includes a full suite of generator, transformer, and auxiliary system protection elements such as differential (87G), loss-of-field (40), reverse power, overexcitation (24), and stator ground protection. The relay uses advanced synchrophasor measurements, arc-flash detection sensors, and high-speed sampling for unparalleled fault response. Dual-redundant processing cores ensure continuous protection even under hardware failures. With IEC 61850, PRP/HSR, and high cybersecurity standards, SEL-400G fits seamlessly into modern power plants. It also supports digital fault recording, breaker wear monitoring, and predictive maintenance analytics.

Key Features

• Generator differential protection

• Loss-of-field, reverse power, and out-of-step

• Arc flash optical detection

• Redundant processing cores

• IEC 61850, PRP/HSR, synchrophasors

• Advanced cyber security

Applications

• Power plant generator protection

• Industrial generation units

• Combined-cycle and thermal plants

• Hydro and renewable generation

Keywords

SEL-400G, generator protection relay, SEL generator relay, 87G protection, arc-flash detection