4.8.2.9
Technical data
Table 706: DOPPDPR Technical data
Characteristic
Value
Operation accuracy
Depending on the frequency of the measured current and
voltage:
f = f
n
±2 Hz
Power measurement accuracy ±3% of the set value or ±0.002
× S
n
Phase angle: ±2°
Start time ,
Typically 45 ms
Reset time
Typically 30 ms
Reset ratio
Typically 0.94
Operate time accuracy
±1.0 % of the set value of ±20 ms
Suppression of harmonics
-50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
4.8.3
Directional reactive power undervoltage protection
DQPTUV
4.8.3.1
Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Directional reactive power under-
voltage protection
DQPTUV
Q> ->,3U<
32Q,27
4.8.3.2
Function block
Figure 387: Function block
4.8.3.3
Functionality
The directional reactive power undervoltage protection function DQPTUV is used at
the grid connection point of distributed power generating units as stipulated by
various grid codes to prevent voltage collapse of the grid due to network faults.
DQPTUV measures phase voltages and current at the grid connection point. The
generating facility is disconnected from the network with a specific time delay if all
phase voltages decrease and remain at or below the specified limit and if reactive
power is simultaneously consumed (that is, under-excitation operation).
1
Measurement mode = “Pos Seq” (default)
2
U = U
n
, f
n
= 50 Hz, results based on statistical distribution of 1000 measurements
3
Includes the delay of the signal output contact
Protection functions
1MRS757644 H
744
620 series
Technical Manual
