ABB 615 series Technical Manual page 383

1MAC059074-MB A
615 series ANSI
Technical Manual
I
10 A
gFd
Yo j j
≈ − ⋅ = − ⋅
V
15 3
ph
GUID-97B578C9-6433-40A1-8900-69BC344E4756 V1 EN
The result is valid regardless of the neutral grounding method.
In this case, the resistive part of the measured admittance is due to leakage losses of the
protected feeder. As they are typically very small, the resistive part is close to zero. Due
to inaccuracies in the voltage and current measurement, the small real part of the apparent
neutral admittance may appear positive. This should be considered in the setting of the
admittance characteristic.
Fault in the forward direction, that is, inside the protected feeder.
Ungrounded network:
Yo Y
=
Bgtot
GUID-5F1D2145-3C0F-4F8F-9E17-5B88C1822566 V1 EN
I I
 
−
gTot gFd
j
≈ ⋅
   
V
ph
 
GUID-A59B653A-E421-4A65-BD70-77512A1106BE V1 EN
Compensated network:
Yo Y Y
= +
Bgtot CC
GUID-F3810944-D0E1-4C9A-A99B-8409F4D3CF05 V1 EN
I j I K I
( 1
( )
+ ⋅ ⋅ − −
Rcc gTot
≈
V
ph
GUID-8F6E7E63-7784-46F1-B1B4-5872F11BDF8C V1 EN
High-resistance grounded network:
Yo Y Y
= +
Bgtot Rn
GUID-F91DA4E4-F439-4BFA-AA0D-5839B1574946 V1 EN
j milliSiemens
1 15 .
= − ⋅
kV
)
gFd
Section 4
Protection functions
(Equation 28)
(Equation 29)
(Equation 30)
(Equation 31)
(Equation 32)
(Equation 33)
377