ABB RELION RET670, Applications Manual

Page: 527 / 1016

The parameters for the directional phase overcurrent protection, four steps OC4PTOC
(51/67) are set via the local HMI or PCM600.
The following settings can be done for OC4PTOC (51/67).
Common base IED values for primary current ( IBase ), primary voltage ( UBase ) and
primary power ( SBase ) are set in the global base values for settings function
GBASVAL.
GlobalBaseSel : This is used to select GBASVAL function for reference of base values.
MeasType : Selection of discrete Fourier filtered ( DFT ) or true RMS filtered ( RMS )
signals. RMS is used when the harmonic contents are to be considered, for example in
applications with shunt capacitors.
Operation : The protection can be set to Enabled or Disabled .
AngleRCA : Protection characteristic angle set in degrees. If the angle of the fault loop
current has the angle RCA, the direction to the fault is forward.
AngleROA : Angle value, given in degrees, to define the angle sector of the directional
function, shown in Figure 260 .
NumPhSel : Number of phases, with high current, required for operation. The setting
possibilities are: 1 out of 3 , 2 out of 3 and 3 out of 3 . The default setting is 1 out of 3 .
PUMinOpPhSel : Minimum current setting level for releasing the directional start
signals in % of IB . This setting should be less than the lowest step setting. The default
setting is 7% of IB .
2ndHarmStab : Operate level of 2nd harmonic current restrain set in % of the
fundamental current. The setting range is 5 - 100 % in steps of 1%. The default setting
is 20%.
1MRK 504 163-UUS A
Section 9
Current protection
Transformer protection RET670 2.2 ANSI 521
Application manual