ABB REL650 series Technical Manual page 246

Section 7
Current protection
7.7.7.3
240
Instrument
transformer
angle error
3I (prim)
0
ANSI06000651 V1 EN
Figure 109: Explanation of RCAComp
Directional residual power protection measuring 3I
φ is defined as the angle between the residual current 3I
compensated with the set characteristic angle RCADir (φ=ang(3I
-jRCADir
-3V e . The function operates when 3I
0
For trip, both the residual power 3I
voltage 3V , shall be larger than the set levels (SN_PU, INRelPU and VNRelPU).
0
When the function is activated binary output signals PICKUP and PUDIRIN are activated.
If the output signals are active after the set delay tDef or after the inverse time delay
(setting TDSN) the binary output signals TRIP and TRDIRIN are activated.
The function shall indicate forward/reverse direction to the fault. Reverse direction is
·cos (φ + 180°) ³ the set value.
defined as 3I · 3V
0 0
Operate area
a
RCAcomp
Characteristic after
angle compensation
3I (to prot)
0
· 3V
0
· 3V · cos φ, the residual current 3I
0 0
1MRK 506 335-UUS A
-3V =V RCA = 0°
0 ref
en06000651_ansi.vsd
· 3V · cos φ
0 0
and the reference voltage
0
)—ang(V
0
· cos φ gets larger than the set value.
0
and the release
0
Technical manual
) ). V =
ref ref