Sensor Inputs For Currents And Voltages - ABB 615 series Technical Manual

Section 3
Basic functions
3.10
104

Sensor inputs for currents and voltages

This chapter gives short examples on how to define the correct parameters for sensors.
Sensors have corrections factors, measured and verified by the sensor
manufacturer, to increase the measurement accuracy of primary values.
Correction factors are recommended to be set. Two types of correction
factors are available for voltage and rogowski sensors. The Amplitude
correction factor is named Amplitude corr. A(B/C) and Angle correction
factor is named Angle corr A(B/C). These correction factors can be found
on the Sensor's rating plate. If the correction factors are not available,
contact the sensor manufacturer for more information.
Rogowski sensor setting example
In this example, an 80 A/0.150 V at 50 Hz sensor is used and the application has a 150 A
nominal current (In). As the Rogowski sensor is linear and does not saturate, the 80 A/
0.150 V at 50 Hz sensor also works as a 150 A/0.28125 V at 50 Hz sensor. When defining
another primary value for the sensor, also the nominal voltage has to be redefined to
maintain the same transformation ratio. However, the setting in the protection relay
(Rated Secondary Value) is not in V but in mV/Hz, which makes the same setting value
valid for both 50 and 60 Hz nominal frequency.
I
n
K
×
r
I
pr
RSV
=
f
n
GUID-6A480073-5C35-4319-8B38-402608D4C098 V2 EN
RSV
I
n
I
pr
f
n
K
r
In this example, the value is as calculated using the equation.
150 A
mV
150
×
80 A
= . 5 625
Hz
50
GUID-13DE42A0-29C0-4FE0-B00B-1215B37E3B7B V2 EN
Rated Secondary Value in mV/Hz
Application nominal current
Sensor-rated primary current
Network nominal frequency
Sensor-rated voltage at the rated current in mV
mV
Hz
1MAC059074-MB A
(Equation 1)
(Equation 2)
615 series ANSI
Technical Manual