![background image](http://html.mh-extra.com/html/abb/relion-615-series/relion-615-series_technical-manual_2395853.webp)
Differential current monitoring
Differential current monitoring supervises the difference between the summed phase
currents I_A, I_B and I_C and the reference current I_REF.
The current operating characteristics can be selected with the
Pickup value
setting. When
the highest phase current is less than 1.0 × In, the differential current limit is defined with
Pickup value
. When the highest phase current is more than 1.0 × In, the differential current
limit is calculated with the equation.
MAX I
A I
B I
C
Pickup value
( _ , _ , _
)
×
GUID-41E8DD52-0C7D-406D-9799-DA48A660D8E5-ANSI V1 EN
(Equation 158)
The differential current is limited to 1.0 × In.
V_A_AB
BLOCK
U_LO
27R
V_B_BC
V_C_CA
Pickup value
Max(I_A , I_B , I_C)
1.0 p.u.
1.0 p.u.
I_DIFF
2.0 p.u.
3.0 p.u.
4.0 p.u.
Max trip current
NON-OPERATE
OPERATE
GUID-D083BF22-574C-4603-971F-5F4371632A28 V2 EN
Figure 436:
CCM operating characteristics
When the differential current I_DIFF is in the operating region, the
FAIL
output is
activated.
The function is internally blocked if any phase current is higher than the set
Max trip
current
. When the internal blocking activates, the
FAIL
output is deactivated
immediately. The internal blocking is used for avoiding false operation during a fault
situation when the current transformers are saturated due to high fault currents.
The value of the differential current is available in the monitored data view on the LHMI
or through other communication tools. The value is calculated with the equation.
1MAC059074-MB A
Section 6
Supervision functions
615 series ANSI
847
Technical Manual
Содержание Relion 615 series
Страница 1: ... RELION PROTECTION AND CONTROL 615 series ANSI Technical Manual ...
Страница 2: ......
Страница 39: ...Section 17 Glossary 1181 Table of contents 615 series ANSI 33 Technical Manual ...
Страница 40: ...34 ...
Страница 64: ...58 ...
Страница 210: ...3 19 4 Settings Section 3 1MAC059074 MB A Basic functions 204 615 series ANSI Technical Manual ...
Страница 216: ...210 ...
Страница 884: ...878 ...
Страница 1038: ...1032 ...
Страница 1136: ...1130 ...
Страница 1172: ...1166 ...
Страница 1180: ...1174 ...
Страница 1186: ...1180 ...
Страница 1192: ...1186 ...
Страница 1193: ...1187 ...
Страница 1194: ......
Страница 1195: ......