Analog Channel Configuration - ABB RELION REX640 Technical Manual

1MRS759142 C
5.4.4
5.4.5
REX640
Technical Manual
impedance faults do not pose imminent danger to power system equipment. However,
they are a substantial threat to humans and properties; people can touch or get close to
conductors carrying large amounts of energy.
ABB has developed a patented technology (US Patent 7,069,116 B2 June 27, 2006,
US Patent 7,085,659 B2 August 1, 2006) to detect a high-impedance fault.
The high-impedance fault detection function PHIZ also contains a blocking
functionality. It is possible to block function outputs.

Analog channel configuration

PHIZ has two analog group inputs which all must be properly configured.
Table 1022: Analog inputs
Input
I3P
IRES
See the preprocessing function blocks in this document for the
possible signal sources.
Improper analog channel configuration causes a validation error if the analog
channels are not completely configured or they do not match with certain settings. For
troubleshooting, check the contents of this chapter and also the preprocessing blocks
in this document. The configuration can be written to the protection relay once the
mismatch is corrected.
Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
PHIZ uses a multi-algorithm approach. Each algorithm uses various features of earth
currents to detect a high-impedance fault.
Although the PHIZ algorithm is very sophisticated, the setting required to operate the
function is simple. The Security Level setting, with the setting range of 1 to 10, is set
to strike a balance between the extremes of security and dependability which together
constitute the reliability of any system. The setting value "10" is more secure than "1".
The higher the Security Level setting, the lower the probability of false detection, but
the system might miss out some genuine fault. On the other hand, a lower setting
would make the system operate more dependably for high-impedance faults in the
line, but the operation is more likely for other transients in the system. There are events
in electrical networks which can cause similar current waveforms like high-
impedance faults. These events could then be detected by the PHIZ algorithm causing
Protection related functions
Description
Three-phase currents
Residual current (measured or calculated)
Section 5
1083