Application - ABB RELION REX640 Technical Manual

1MRS759142 C
5.4.6
REX640
Technical Manual
non-harmonic components within the available data window can play a vital role in
the high-impedance fault detection. A major challenge is to develop a data model that
acknowledges that high-impedance faults could take place at any time within the
observation window of the signal and could be delayed randomly and attenuated
substantially. The model is motivated by extensive research, actual experimental
observations in the laboratory, field testing and what traditionally represents an
accurate depiction of a non-stationary signal with a time-dependent spectrum.
GUID-03B44D72-F76A-4299-8E45-FA59EA37B4EC V1 EN
Figure 585: Validation of PHIZ on
gravel
GUID-6B3EAEA5-1EE3-42D0-A19A-9A0156014E2B V1 EN
Figure 587: Validation of PHIZ on
sand

Application

PHIZ is used to detect a downed conductor dropping to a very resistive ground,
causing an earth fault which is very difficult to detect by a conventional protection
relay functionality. PHIZ is then targeted to be used with overhead lines. PHIZ must
be used in electrical networks with efficiently grounded or isolated neutral.
Electric power lines experience faults for many reasons. In most cases, electrical
faults manifest in mechanical damage, which must be repaired before returning the
line to service.
Protection related functions
GUID-EC698E87-2F07-4E53-90A5-C3F18B20B462 V1 EN
Figure 586: Validation of PHIZ on
concrete
GUID-DDE2DA5D-5FF2-424C-B2B0-C1D5C5CC8378 V1 EN
Figure 588: Validation of PHIZ on
grass
Section 5
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