Table 316: Operation criteria
Operation mode Description
Yo Admittance criterion
Bo Susceptance criterion
Go Conductance criterion
Yo, Go Admittance criterion combined with the
conductance criterion
Yo, Bo Admittance criterion combined with the
susceptance criterion
Go, Bo Conductance criterion combined with the
susceptance criterion
Yo, Go, Bo Admittance criterion combined with the
conductance and susceptance criterion
The options for the Directional mode setting are "Non-directional", "Forward" and
"Reverse".
Figure 159, Figure 160 and Figure 161 illustrate the admittance characteristics
supported by EFPADM and the settings relevant to that particular characteristic.
The most typical characteristics are highlighted and explained in details in the
chapter
Neutral admittance characteristics . Operation is achieved when the
calculated neutral admittance Yo moves outside the characteristic (the operation
area is marked with gray).
The settings defining the admittance characteristics are given in
primary milliSiemens (mS). The conversion equation for the
admittance from secondary to primary is:
GUID-2F4EAEF7-0D92-477F-8D4C-00C7BEDE04CB V1 EN (Equation 28)
ni
CT
CT ratio for the residual current Io
nu
VT
VT ratio for the residual voltage Uo
Example: Admittance setting in the secondary is 5.00 milliSiemens.
The CT ratio is 100/1 A and the VT ratio is 11547/100 V. The
admittance setting in the primary can be calculated.
Y milliSiemens
A
V
milliSiemens
pri
= ⋅ =5 00
100 1
11547 100
4 33. .
GUID-9CFD2291-9894-4D04-9499-DF38F1F64D59 V1 EN
Section 4 1YHT530004D05 D
Protection functions
320 615 series
Technical Manual
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