Digital Inputs; Filtering Of Digital Inputs - ABB REX 521 Technical Reference Manual, General

1MRS 751108-MUM
4.1.7.
4.1.7.1.
Protection Relay
Technical Reference Manual, General
Phase displacement error at voltage U
(d = error in degrees)
5RJRZVNL FRLO
Amplitude error at the whole measuring range
(e = error in per cent)
Phase displacement error at the whole
measuring range
(e = error in degrees)
9ROWDJH GLYLGHU
Amplitude error at the whole measuring range
(e = error in per cent)
Phase displacement error at the whole
measuring range
(e = error in degrees)
Primary values and measurement device settings
The conversion between primary and per unit values are based on the analogue
scales of the I (I pu-scale), I
L1 L1
and U (U pu-scale). To ensure proper operation, it must be checked that the
0 0
analogue scales of the phase currents I
analogue scales of the phase-to-phase voltages U

Digital inputs

The digital inputs of the protection relay are voltage-controlled and optically
isolated. For technical data of the digital inputs, refer to Table 4.2.1-3 on page 31.

Filtering of digital inputs

The filter time eliminates debounces and short disturbances on digital inputs. The
filter time may be set individually for each input.
)LJ  )LOWHULQJ RI D GLJLWDO LQSXW
Phase displacement error = - d
n
Amplitude correction factor
= 1/(1+ e/100)
Phase displacement error = - e
Amplitude correction factor
= 1/(1+ e/100)
Phase displacement error = - e
(I pu-scale), I (I pu-scale), U
0 0 0b 0b
, I and I , and correspondingly, the
L1 L2 L3
, U
12 23
REX 521
(U pu-scale)
12 12
and U are identical.
31
15