ABB REG650 ANSI, Technical Manual

Page: 215 / 728

-3U
0
=U
ref
Operate area
Instrument
transformer
angle error
3I
0
(prim)
3I
0
(to prot)
a
Characteristic after
angle compensation
RCAcomp
en06000651.vsd
RCADir = 0º
IEC06000651 V2 EN
Figure 103: Explanation of RCAComp
8.3.7.3 Directional residual power protection measuring 3I
0
· 3U
0
· cos φ
φ is defined as the angle between the residual current 3I
0
and the reference voltage
compensated with the set characteristic angle RCADir (φ=ang(3I
0
)—ang(U
ref
) ). U
ref
= -3U
0
e
-jRCADir
. The function operates when 3I
0
· 3U
0
· cos φ gets larger than the set
value.
For trip, both the residual power 3I
0
· 3U
0
· cos φ, the residual current 3I
0
and the
release voltage 3U
0
, shall be larger than the set levels ( SN> , INRel> and UNRel> ).
When the function is activated binary output signals START and STDIRIN are
activated. If the output signals are active after the set delay
tDef or after the inverse
time delay (setting kSN ) the binary output signals TRIP and TRDIRIN are activated.
The function shall indicate forward/reverse direction to the fault. Reverse direction is
defined as 3I
0
· 3U
0
·cos (φ + 180°)
³
the set value.
This sub-function has the possibility of choice between definite time delay and inverse
time delay.
1MRK 502 048-UEN A
Section 8
Current protection
209
Technical manual