GE UR T60 - Page 279

GE Multilin T60 Transformer Protection System 5-141
5 SETTINGS 5.5 FLEXLOGIC™
5
The FLEXELEMENT 1 PICKUP setting specifies the operating threshold for the effective operating signal of the element. If set
to “Over”, the element picks up when the operating signal exceeds the FLEXELEMENT 1 PICKUP value. If set to “Under”, the
element picks up when the operating signal falls below the FLEXELEMENT 1 PICKUP value.
The FLEXELEMENT 1 HYSTERESIS setting controls the element dropout. It should be noticed that both the operating signal
and the pickup threshold can be negative facilitating applications such as reverse power alarm protection. The FlexEle-
ment™ can be programmed to work with all analog actual values measured by the relay. The
FLEXELEMENT 1 PICKUP set-
ting is entered in per-unit values using the following definitions of the base units:
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 dia-
gram.
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.
Table 5–14: FLEXELEMENT™ BASE UNITS
DCmA BASE = maximum value of the DCMA INPUT MAX setting for the two transducers configured
under the +IN and –IN inputs.
FREQUENCY f
BASE
= 1 Hz
PHASE ANGLE ϕ
BASE
= 360 degrees (see the UR angle referencing convention)
POWER FACTOR PF
BASE
= 1.00
RTDs BASE = 100°C
SOURCE CURRENT I
BASE
= maximum nominal primary RMS value of the +IN and –IN inputs
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)