Cos Φ - ABB REC650 Technical Manual

Section 6
Current protection
6.5.7.3
116
Instrument
transformer
angle error
3I
0
IEC06000651 V2 EN
Figure 47: 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
= -3U e . The function operates when 3I
0
value.
For trip, both the residual power 3I
release voltage 3U , shall be larger than the set levels (SN>, INRel> and UNRel>).
0
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
·cos (φ + 180°) ³ the set value.
defined as 3I · 3U
0 0
This sub-function has the possibility of choice between definite time delay and inverse
time delay.
Operate area
a
RCAcomp
Characteristic after
angle compensation
3I (to prot)
(prim)
0
· 3U · cos φ, the residual current 3I
0 0
1MRK 511 287-UEN A
RCADir = 0º
-3U =U
0 ref
en06000651.vsd
· 3U · cos φ
0 0
and the reference voltage
0
)—ang(U
0
· 3U · cos φ gets larger than the set
0 0
Technical manual
) ). U
ref ref
and the
0