MICROENER IM30-B00, Руководство по эксплуатации, Страница: 5 / 23

IM30-B00
Doc. N°
MO-0132-ING
Copyright 2010 - Microener Firmware 2.0X Data 22.04.2008 Rev. 2 Pag 5 of 23
r s
a
t T K B
1
Is
I
A
t(I)
  

















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
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
2.2 - Algorithm of the time current curves
The Time Current Curves are generally calculated with the following equation :
(1) where :
t(I) = Actual trip time delay when the input current equals I
Is = Set minimum pick-up level
K
=
T
s
= Set time delay : t(I) = T
s
when
tr = Operation time of the output relay on pick-up.
The parameters A, B and a have different values for the different Time Current Curves.
Curve Name Curve Identifier A B a
IEC A Inverse A 0.14 0 0.02
IEC B Very Inverse B 13.5 0 1
IEC C Extremely Inverse C 80 0 2
IEEE Moderate Inverse MI 0.0104 0.0226 0.02
IEEE Short Inverse SI 0.00342 0.00262 0.02
IEEE Very Inverse VI 3.88 0.0963 2
IEEE Inverse I 5.95 0.18 2
IEEE Extremely Inverse EI 5.67 0.0352 2
For the IEC curves, being B = 0, the Time/Current equation (1), becomes:
Where Kt = (10
a
-1)Ts is the time multiplier
1
a
B
1 10
A









10
I
I
s

 
 
tr
1
Is
I
Kt
tr
1
Is
I
Ts 1 - 10
1'
a a
a








 



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