ABB RELION REX640 Technical Manual page 1562

Section 9
Control functions
1556
(sin I sin I
φ φ
⋅ − ⋅
1 TR 1 2 TR
I
=
ci
2
GUID-9F3F582C-C220-4ECB-9494-6FF917030E55 V1 EN
I Current magnitude of regulator 1
TR1
I Current magnitude of regulator 2
TR2
φ Phase angle between U_A and I_A in regulator 1
1
φ Phase angle between U_A and I_A in regulator 2
2
The circulating current can be read from the monitored data I_CIR.
Using the circulating current, the compensation term U
equation
I
Stability factor
−
ci
U
= ⋅
ci
I
100
CT _ 1 n
GUID-7B6C171F-EE77-41E7-B7DB-0BE73A88A824 V1 EN
I Circulating current
ci
I Nominal primary current of the CT
CT_n1
Stability factor Stability setting (the recommended value depends on the loop impedance)
The value of U , which can be positive or negative, is added to the Band center voltage
ci
U (Equation 338). According to
s
from the other protection relays is needed.
Parallel unit detection and the MCC mode
The network connection status information is essential for the MCC operation mode.
The status FALSE needs to be connected to the CON_STATUS input to ensure a
proper operation of the MCC calculation if the transformer is disconnected but
OL5ATCC remains in the MCC mode. This way the disconnected transformer is
excluded from the circulating current calculations.
The CON_STATUS input is used to identify if a transformer controller can send the
current information to other transformer controllers for circulating current
minimization purposes. As a result, this input has effect only in the MCC or Manual
active operation modes. In these modes, if CON_STATUS is TRUE, the information
transmission is started. The circulating current information receiving is allowed only
in the MCC active operation mode when CON_STATUS is TRUE. PAR_UNIT_MCC
can be seen in the Monitored data view.
)
2
U
⋅
n
Figure 815 and Equation
1MRS759142 C
(Equation 343)
can be calculated with the
ci
(Equation 344)
343, the phasor information
REX640
Technical Manual