ABB Remote I/O RIO600 - Page 127

taking into consideration the possible network topology changes, compensation coil
and parallel resistor switching status and compensation degree variations.
Multi-frequency admittance calculation
Multi-frequency admittance calculation module calculates neutral admittances
utilizing fundamental frequency and the 2nd, 3rd, 5th, 7th and 9th harmonic
components of residual current and zero-sequence voltage. The following
admittances are calculated, if the magnitudes of a particular harmonic in residual
current and zero-sequence voltage are measurable by the IED.
Fundamental frequency admittance (conductance and susceptance)
Y
I
U
G j B
o o0
1
0
1
0
1
1 1
3
=
⋅
−
= + ⋅
GUID-594F3E58-1090-49B0-BB46-B531EA1FDF4D V1 EN (Equation 8)
Y
0
1
Fundamental frequency neutral admittance phasor
I
0
1
Fundamental frequency zero-sequence current phasor
( )
I I I
A B C
1 1 1
3
+ +
U
0
1
Fundamental frequency zero-sequence voltage phasor
( )
U U U
A B C
1 1 1
3
+ +
G
0
1
Fundamental frequency conductance,
Re( )Y
0
1
B
0
1
Fundamental frequency susceptance,
Im( )Y
0
1
Harmonic susceptances
1MRS757488 H Section 6
Commissioning
RIO600 119
Installation and Commissioning Manual