GE T60

5-178 T60 Transformer Protection System GE Multilin
5.5 FLEXLOGIC 5 SETTINGS
5
The FLEXELEMENT 1 HYSTERESIS setting defines the pickup–dropout relation of the element by specifying the width of the
hysteresis loop as a percentage of the pickup value as shown in the FlexElement direction, pickup, and hysteresis diagram.
The FLEXELEMENT 1 DT UNIT setting specifies the time unit for the setting FLEXELEMENT 1 dt. This setting is applicable only if
FLEXELEMENT 1 COMP MODE is set to “Delta”. The FLEXELEMENT 1 DT setting specifies duration of the time interval for the
rate of change mode of operation. This setting is applicable only if FLEXELEMENT 1 COMP MODE is set to “Delta”.
This FLEXELEMENT 1 PKP DELAY setting specifies the pickup delay of the element. The FLEXELEMENT 1 RST DELAY setting
specifies the reset delay of the element.
SOURCE ENERGY
(Positive and Negative Watthours,
Positive and Negative Varhours)
E
BASE
= 10000 MWh or MVAh, respectively
SOURCE POWER P
BASE
= maximum value of V
BASE
 I
BASE
for the +IN and –IN inputs
SOURCE THD & HARMONICS BASE = 1%
SOURCE VOLTAGE V
BASE
= maximum nominal primary RMS value of the +IN and –IN inputs
SYNCHROCHECK
(Max Delta Volts)
V
BASE
= maximum primary RMS value of all the sources related to the +IN and –IN inputs
VOLTS PER HERTZ BASE = 1.00 pu
XFMR DIFFERENTIAL CURRENT
(Xfmr Iad, Ibd, and Icd Mag)
I
BASE
= maximum primary RMS value of the +IN and -IN inputs
(CT primary for source currents, and transformer reference primary current for transformer
differential currents)
XFMR DIFFERENTIAL
HARMONIC CONTENT
(Xfmr Harm2 Iad, Ibd, and Icd Mag)
(Xfmr Harm5 Iad, Ibd, and Icd Mag)
BASE = 10%
XFMR RESTRAINING CURRENT
(Xfmr Iar, Ibr, and Icr Mag)
I
BASE
= maximum primary RMS value of the +IN and -IN inputs
(CT primary for source currents, and transformer reference primary current for transformer
differential currents)
Z
BASE
Z
BASE
= PhaseVTSecondary / PhaseCTSecondary, where PhaseVTSecondary and
PhaseCTSecondary are the secondary nominal voltage and the secondary nominal current of the
distance source. In case multiple CT inputs are summed as one source current and mapped as
the distance source, use the PhaseCTSecondary value from the CT with the highest primary
nominal current.
Distance source is specified in setting under
SETTINGS > GROUPED ELEMENTS > SETTING
GROUP 1(6) > DISTANCE.
PhaseVTSecondary and PhaseCTSecondary are specified in setting under SETTINGS > SYSTEM
SETUP > AC INPUTS.
Table 5–22: FLEXELEMENT BASE UNITS