Table 75. Line differential protection with in-zone power transformer (LNPLDF)
Characteristics Value
Operation accuracy
1)
Depending on the frequency of the measured current: f
n
±2 Hz
Low stage ±2.5% of the set value
High stage ±2.5% of the set value
Minimum Typical Maximum
High stage, operate time
2)3)
22 ms 25 ms 29 ms
Reset time Typically 40 ms
Reset ratio Typically 0.96
Retardation time (Low stage) <40 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±20 ms
Operate time accuracy in inverse time mode
±5.0% of the set value or ±20 ms
4)
1) With the symmetrical communication channel (as when using dedicated fiber optic).
2) Without additional delay in the communication channel (as when using dedicated fiber optic).
3) Including the delay of the output contact. When differential current = 2 ×
High operate value
and f
n
= 50 Hz with galvanic pilot wire link + 5 ms.
4)
Low operate value
multiples in range of 1.5...20.
Table 76. Line differential protection with in-zone power transformer (LNPLDF) main settings
Parameter
Function Value (Range) Description
High operate value LNPLDF 200...4000 % I
n
Instantaneous stage operate value
Low operate value LNPLDF 10...200 % I
n
Basic setting for the stabilized stage
start
Operate delay time LNPLDF 45...200000 ms Operate delay time for stabilized stage
Operate curve type LNPLDF 1=ANSI Ext. inv.
3=ANSI Norm. inv.
5=ANSI Def. Time
9=IEC Norm. inv.
10=IEC Very inv.
12=IEC Ext. inv.
15=IEC Def. Time
Selection of time delay curve for
stabilized stage
Time multiplier LNPLDF 0.05...15.00 Time multiplier in IDMT curves
Start value 2.H LNPLDF 10...50 % The ratio of the 2. harmonic component
to fundamental component required for
blocking
CT ratio correction LNPLDF 0.200...5.000 Remote phase current transformer ratio
correction
Table 77. High-impedance fault detection (PHIZ) main settings
Parameter
Function Value (Range) Step
Security Level PHIZ 1...10 1
System type PHIZ 1=Grounded
2=Ungrounded
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