t6L2: This is an additional time delay to trip phase L2 if the phase preference is set
to trip phase L2 in zone 6. The default setting is 0.0s.
U0Min: This is used to check the minimum residual voltage on phase L1 if the start
signal falls back, and indicates the fault on phase L2 is cleared successfully. The
default value is 50% UBase
.
tVL2: This is used to extend the time for phase L2 to check the voltage shift. For
the times from t0L2 to t6L2, a settable time tVL2 (operation time extension L2) is
added. When a cross country fault occurs and the phase L1 has tripped, wait for
some time to ensure that:
• The fault on phase L2 is cleared successfully
• The voltage on phase L2 has recovered
• The distance and residual protection functions have reset.
OpModetGL2: This is used for Off/On operation of an additional timer tGL2 used
in the compensated earthed network. The default setting is On.
tGL2: This is an additional time delay to trip L2 in compensated earthing. If the
start signal continues to be active, trip is given after expiration tPEZx plus tGL2.
The default setting is 0.6s.
dUOverdt: This is the rate of change of voltage for phase L1 and phase L2. When
the priority L1 before L2 is selected, the time steps t1L2, t2L2, t3L2, t4L2, t5L2 and
t6L2 are extended by tVL2. During trip time of the corresponding zone, a
normalization of the supply voltage can be identified (i.e. dUL1/dt < dUOverdt and
dUL2/dt> dUOverdt). If a restrike of the earth fault is detected during the tVL2
time (i.e. dUL1/dt > dUOverdt, dUL2/dt < dUOverdt), an instantaneous trip will be
issued. Calculation of algorithm for both voltage step functions dUL1/dt and
dUL2/dt is set with a common parameter dUOverdt. The default setting is 100 V/s.
Stub line
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ModeStubLine: This is used to enable/disable the compensated network contains a
stub line.
UPPMin: This is the minimum phase-to-phase voltage in %UB in case of a stub
line. This is considered before deciding to trip the line that has lower phase-to-earth
voltage. The default setting is 80% UB.
tI0Stub: Time delay to trip for residual current in case of a stub line. The default
setting is 0.2s.
KU: This is the phase-to-earth voltage ratio in case of a stub line.
7.2.2.2 Solidly earthed systems
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In directly earthed networks, a distinction is made between the following types of
faults:
1MRK 506 375-UEN A Section 7
Impedance protection
Railway application RER670 2.2 IEC 113
Application manual
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