Negative-Sequence Overvoltage Protection (Nsptov); Negative-Sequence Overvoltage Protection (Nsptov) Main Settings; Overexcitation Protection (Oepvph) - ABB RET620 Product Manual

Transformer Protection and Control
RET620
Product version: 2.0
Table 47. Negative-sequence overvoltage protection (NSPTOV)
Characteristic
Operation accuracy
1)2)
Start time
Reset time
Reset ratio
Retardation time
Operate time accuracy in definite time mode
Suppression of harmonics
1) Negative-sequence voltage before fault = 0.0 × U
distribution of 1000 measurements
2) Includes the delay of the signal output contact
Table 48. Negative-sequence overvoltage protection (NSPTOV) main settings
Parameter
Start value
Operate delay time
Table 49. Overexcitation protection (OEPVPH)
Characteristic
Operation accuracy
1)2)
Start time
Reset time
Reset ratio
Retardation time
Operate time accuracy in definite-time mode
Operate time accuracy in inverse-time mode
1) Results based on statistical distribution of 1000 measurements
2) Includes the delay of the signal output contact
Table 50. Overexcitation protection (OEPVPH) main settings
Parameter
Start value
Time multiplier
Operate delay time
Cooling time
Operating curve type
ABB
Start value
U = 1.1 × set
Fault
Start value
U = 2.0 × set
Fault
, f = 50 Hz, negative-sequence overvoltage with nominal frequency injected from random phase angle, results based on statistical
n n
Function
NSPTOV
NSPTOV
Function
OEPVPH
OEPVPH
OEPVPH
OEPVPH
OEPVPH
Value
Depending on the frequency of the voltage measured: f
±1.5% of the set value or ±0.002 × U
Minimum Typical
33 ms 35 ms
24 ms 26 ms
< 40 ms
Typical 0.96
< 35 ms
±1.0% of the set value or ±20 ms
DFT: -50 dB at f = n × f , where n = 2, 3, 4, 5,...
n
Value (Range)
0.010...1.000 x U
n
40...120000 ms
Value
Depending on the frequency of the voltage measured: fn ±2 Hz
±2.5% of the set value or 0.01 x Ub/f
Frequency change
Voltage change
< 60 ms
Typical 0.96
< 45 ms
±1.0% of the set value or ±20 ms
±5.0% of the theoretical value or ±50 ms
Value (Range)
100...200 %
0.1...100.0
200...200000 ms
5...10000 s
Definite or inverse time
Curve type: 5, 15, 17, 18, 19, 20
1MRS757846 A
±2 Hz
n
n
Maximum
37 ms
28 ms
Step
0.001
1
Typical 200 ms (±20 ms)
Typical 100 ms (±20 ms)
Step
1
0.1
10
1
35