ABB REG670 - Operation Principle of Zone 3

Sl.No Measuring Loop Voltage Phasor Current Phasor
1
IL1
1 0UL E U-
1IL
2
IL2
2 0UL E U-
2IL
3
IL3
3 0UL E U-
3IL
Operate time
The operate time delay for zone 2 can be provided using the setting tZ2.
Zone 2 is provided load encroachment detection feature based on positive sequence
components measurements.. This feature avoids the function from operating due to
load encroachment. The load encroachment feature for zone 2 can be set using
LoadEnchModZ2 to On or Off.
7.10.7.3 Operation principle of zone 3
Zone 3 is used to cover up to the HV side of the transformer, interconnecting bus
network and outgoing lines. The time to trip should be provided in order to coordinate
with the transmission line protection.
The zone 3 will provide protection from phase-to-earth, phase-phase and three-phase
faults on the HV side of the system. The zone 3 functionality is same as zone 2 hence
the explanation of zone 2 applies except the zone 3 has separate reach (Z3Fwd,
Z3Rev), operate timer (tZ3) and load encroachment enable (LoadEnchModZ3)
settings.
7.10.7.4 Load encroachment
The load encroachment characteristics can be set for zone2 and zone3. Load
encroachment can be enabled for zone 2 by setting LoadEnchModZ2 to On. Similarly
the load encroachment for zone 3 can be enabled by setting LoadEnchModZ3 to On.
The load encroachment characteristic is based on positive sequence quantities and can
be set using the settings RLd and ArgLd.
RLd is the positive sequence resistive reach value in percentage. ArgLd is angle in
degrees from the origin to the resistive axis as shown in Figure
154.
Section 7 1MRK502052-UEN B
Impedance protection
330
Technical manual