Schweitzer Engineering Laboratories SEL-351-5, Инструкция по эксплуатации

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4.42
SEL-351-5, -6, -7 Relay Instruction Manual
Date Code 20070117
Loss-of-Potential, Load Encroachment, and Directional Element Logic
Directional Control Settings
If the load-encroachment logic is enabled (enable setting ELOAD = Y), then
setting 50P32P is not made or displayed, but is fixed internally at:
0.5 A secondary (5 A nominal phase current inputs,
IA
,
IB
,
IC
)
0.1 A secondary (1 A nominal phase current inputs, IA , IB , IC )
Z2F—Forward Directional Z2 Threshold
Z2R—Reverse Directional Z2 Threshold
Setting Range:
–64.00 to 64.00
Ω
secondary (150 V voltage inputs,
VA
,
VB
,
VC
;
5 A nominal phase current inputs, IA , IB , IC )
–320.00 to 320.00
Ω
secondary (150 V voltage inputs, VA , VB , VC ;
1 A nominal phase current inputs,
IA
,
IB
,
IC
)
–128.00 to 128.00
Ω
secondary (300 V voltage inputs,
VA
,
VB
,
VC
;
5 A nominal phase current inputs, IA , IB , IC )
–640.00 to 640.00
Ω
secondary (300 V voltage inputs, VA , VB , VC ;
1 A nominal phase current inputs,
IA
,
IB
,
IC
)
Z2F and Z2R are used to calculate the Forward and Reverse Thresholds,
respectively, for the negative-sequence voltage-polarized directional elements
(see
Figure 4.9 and Figure 4.20 ).
If enable setting E32 = Y, settings Z2F and Z2R (negative-sequence
impedance values) are calculated by the user and entered by the user, but
setting Z2R must be greater in value than setting Z2F by 0.1
Ω
secondary.
Z2F and Z2R Set Automatically
If enable setting E32 = AUTO, settings Z2F and Z2R (negative-sequence
impedance values) are calculated automatically, using the positive-sequence
line impedance magnitude setting Z1MAG as follows:
Z2F =
Z1MAG/2
(
Ω
secondary)
Z2R = Z1MAG/2 + z (
Ω
secondary; “z” listed in table below)
Figure 4.25 and Figure 4.26 and supporting text concern the zero-sequence
impedance network, relay polarity, and the derivation of settings Z0F and
Z0R. The same general approach outlined for deriving settings Z0F and Z0R
can also be applied to deriving settings Z2F and Z2R in the negative-sequence
impedance network, though the preceding method of automatically making
settings Z2F and Z2R usually suffices.
Relay Configuration z (
Ω
secondary)
5 A nominal current, 150 V voltage inputs 0.1
5 A nominal current, 300 V voltage inputs 0.2
1 A nominal current, 150 V voltage inputs 0.5
1 A nominal current, 300 V voltage inputs 1.0
NOTE:
If the above calculation of
Z2F and Z2R exceeds the setting
range, the quantity is set to the upper
limit of the setting range.