Sensor Inputs For Currents And Voltages - ABB RELION REX640 Technical Manual

1MRS759142 F
Table 91: Calculated voltages for different connection types
Voltage connection
3 × ph-n
3 × ph-n + Uo
2 × ph-n
2 × ph-n + Uo
3 × ph-ph
3 × ph-ph + Uo
2 × ph-ph
2 × ph-ph + Uo
3.12

Sensor inputs for currents and voltages

This chapter gives short examples on how to define the correct parameters for
sensor measurement interfaces.
Figure 56: Example of ABB Rogowski current sensor KECA 80 D85 rating plate
Current (Rogowski) sensor setting example
In this example, an 80 A/0.150 V at 50 Hz (0.180 V at 60 Hz) sensor, such as
the example shown in
application has a 150 A nominal current (In) corresponding to the protected
object's nominal current. The application nominal current is set to Rogowski
1
Uo assumed zero.
REX640
Technical Manual
Phase-to-phase
voltages (Ph-Ph)
yes, calculated
yes, calculated
yes, calculated
yes, calculated
yes
yes
yes, missing ph-ph
calculated
yes, missing ph-ph
calculated
Sensors can have correction factors, measured and verified by the sensor
manufacturer, to increase the measurement accuracy. Correction factors
are recommended to be set to the relay. Two types of correction factors
are available for voltage and current (Rogowski) sensors. The Amplitude
correction factor is named
Angle corr A(B/C) . These correction factors can be found
factor is named
on the Sensor's rating plate and/or sensor routine test protocol. If the
correction factors are not available, contact the sensor manufacturer for
more information.
Figure 56 , is used in a 50 Hz electrical network. The
Phase-to-neutral
voltages (Ph-n)
yes
yes
1
yes, missing ph-n cal-
1
culated
yes, missing ph-n cal-
culated
1
yes, calculated
yes, calculated
1
yes, calculated
yes, calculated
Amplitude corr. A(B/C) and Angle correction
Basic functions
Residual voltage Uo
yes, calculated
yes
no
yes
no
yes
no
yes
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