ABB RET670 Applications Manual page 464

Section 3
IED application
458
The setting IBase gives the base current in A. Normally the primary rated current of the
CT feeding the protection should be chosen.
The setting VBase gives the base voltage in kV. Normally the system phase to ground
voltage is chosen.
The setting SBase gives the base voltage in kVA. Normally IBase · VBase is chosen.
With the setting OpModeSel the principle of directional function is chosen.
With OpModeSel set to 3I0cosfi the current component in the direction equal to the
characteristic angleRCADir has the maximum sensitivity. The characteristic for
RCADir is equal to 0° is shown in figure 201.
ANSI06000648 V1 EN
Figure 201: Characteristic for RCADir equal to 0°
The characteristic is for RCADir equal to -90° is shown in figure 202.
V
RCA = 0°, ROA = 90°
ref
3I
0
= ang(3I ) - ang(3V
0 ref
3I cos
0
en06000648_ansi.vsd
1MRK504116-UUS C
)
-3V =V
0 ref
Application manual