234 D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
GROUPED PROTECTION ELEMENTS CHAPTER 7: PROTECTION
I
2
t curves
The I
2
t curves are derived as follows:
Eq. 16
Eq. 17
where
• T
operate
= operate time in seconds
• TDM = multiplier setting
• I = input current
• I
pickup
= pickup current setting
• T
reset
= reset time in seconds (assuming the energy capacity is 100% and the reset
mode is “Timed”)
Table 12: I
2
t curve trip times (in seconds)
2.0 2.310 1.499 1.064 0.885 0.784 0.719 0.674 0.640 0.614 0.594
4.0 4.621 2.997 2.128 1.770 1.569 1.439 1.348 1.280 1.229 1.188
6.0 6.931 4.496 3.192 2.656 2.353 2.158 2.022 1.921 1.843 1.781
8.0 9.242 5.995 4.256 3.541 3.138 2.878 2.695 2.561 2.457 2.375
10.0 11.552 7.494 5.320 4.426 3.922 3.597 3.369 3.201 3.072 2.969
IAC Short Inverse
0.5 0.072 0.047 0.035 0.031 0.028 0.027 0.026 0.026 0.025 0.025
1.0 0.143 0.095 0.070 0.061 0.057 0.054 0.052 0.051 0.050 0.049
2.0 0.286 0.190 0.140 0.123 0.114 0.108 0.105 0.102 0.100 0.099
4.0 0.573 0.379 0.279 0.245 0.228 0.217 0.210 0.204 0.200 0.197
6.0 0.859 0.569 0.419 0.368 0.341 0.325 0.314 0.307 0.301 0.296
8.0 1.145 0.759 0.559 0.490 0.455 0.434 0.419 0.409 0.401 0.394
10.0 1.431 0.948 0.699 0.613 0.569 0.542 0.524 0.511 0.501 0.493
Multiplier
(TDM)
Current (I / I
pickup
)
1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0
0.01 0.44 0.25 0.11 0.06 0.04 0.03 0.02 0.02 0.01 0.01
0.10 4.44 2.50 1.11 0.63 0.40 0.28 0.20 0.16 0.12 0.10
1.00 44.44 25.00 11.11 6.25 4.00 2.78 2.04 1.56 1.23 1.00
10.00 444.44 250.00 111.11 62.50 40.00 27.78 20.41 15.63 12.35 10.00
100.00 4444.4 2500.0 1111.1 625.00 400.00 277.78 204.08 156.25 123.46 100.00
600.00 26666.
7
15000.
0
6666.7 3750.0 2400.0 1666.7 1224.5 937.50 740.74 600.00
Multiplier
(TDM)
Current (I / I
pickup
)
1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0
,
,
SLFNXS
7
RSHUDWH
7'0î
²
,
,
SLFNXS
7
UHVHW
7'0î