Tap Changer Control With Voltage Regulator (Olatcc) - ABB RET620 Product Manual

Transformer Protection and Control
RET620
Product version: 2.0
Table 70. Tap changer control with voltage regulator (OLATCC)
Characteristic
1)
Operation accuracy
Operate time accuracy in definite time mode
Operate time accuracy in inverse time mode
Reset ratio for control operation
Reset ratio for analogue based blockings (except run back raise
voltage blocking)
1) Default setting values used
2) Voltage before deviation = set Band center voltage.
42
Value
Depending on the frequency of the current measured: f
Differential voltage U
(in measured voltages < 2.0 x U
Operation value = ± 1.5% of the U
+ 4.0% / - 0% of the set value
2)
+ 8.5% / - 0% of the set value
2)
(at theoretical B in range of 1.1...5.0)
Also note fixed minimum operate time (IDMT) 1 s.
Typical 0.80 (1.20)
Typical 0.96 (1.04)
= ± 0.5% of the measured value or ± 0.005 x U
d
)
n
for Us = 1.0 x U
d
1MRS757846 A
±2 Hz
n
n
n
ABB