1) Sequence Currents Fast Trip Protection. This
protection consists of positive sequence current and
negative sequence current protections, which protect the
motor against severely symmetric and asymmetric faults
and trip without time delay. As we know, when motor
starts, the stator currents are larger than its rated currents,
the protection should and can identify this special state
and increase the thresholds of positive and negative
sequence currents automatically to avoid tripping
unexpectedly.