ERL L-PRO 4000, Руководство пользователя

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7 Acceptance/Protection Function Test Guide
7-22 L-PRO 4000 User Manual D02706R02.30
End of 21P2 test.
21N2 Ground
Distance Test
Zone 2 Phase-to-Neutral Under Impedance
Settings
• Positive Sequence Secondary Line Impedance (100% of line) = 5.9

• Positive Sequence Line Angle (Z1) = 80

• 21N2 = 7.38

(Maximum Reach = 125% of line at maximum torque angle
of 80

) compensated as per 21N calculations to: 11.58


76.5

• Resistive Component compensated to: 9.41


-3.5

• Time Delay = 0 (expect 1.3 cycles, 22 ms or less)
• 3I0 Current Supervision = 1.5 A (minimum zero sequence current to allow
21N2 to operate)
• I Phase Current Supervision = 1.5 A (minimum phase current to allow 21N2
to operate)
Figure 7.14: Ground Distance Logic (21N)
This test demonstrates testing a single line (Phase A) to a ground fault.
Preliminary calculations
Since this is a single-phase test, use the compensated impedance value calcu-
lated above; the calculated fault impedance
Z
fault
is:
0
4ms
21N# - Zan
50 Ia
Directional Element
21N# - Zbn
50 Ib
Directional Element
21N# - Zcn
50 Ic
Directional Element
N - Zone #
60
TN#
0
Out 1
21N
Generic Phase Distance
Logic (# = any zone)
50N 3IO
50N 3IO
50N 3IO
142
141
138
139
140
(29)
Z
fault
V
fault
I
fault
--------------- =