Arcteq AQ-F213, Инструкция по эксплуатации

Страница: 325 / 455

Figure. 5.4.8 - 203. Simplified function block diagram of the Δφ function.
Measured input
The function block uses analog voltage measurement values and always uses complex measurement
from samples. A -20 ms averaged value of the selected magnitude is used for pre-fault data
registering.
Table. 5.4.8 - 211. Measurement inputs of the vector jump function.
Signal Description Time base
U
1
L-L Measured line-to-line voltage U
1
/V
5ms
U
2
L-L Measured line-to-line voltage U
2
/V 5ms
U
3
L-L Measured line-to-line voltage U
3
/V 5ms
U
1
L-N Measured line-to-neutral voltage U
1
/V
5ms
U
2
L-N Measured line-to-neutral voltage U
2
/V
5ms
U
3
L-N Measured line-to-neutral voltage U
3
/V 5ms
U
4
Measured voltage U
4
/V
5ms
The selection of the used AI channel is made with a setting parameter. In all possible input channel
variations the pre-fault condition is presented with a 20 ms averaged history value from -20 ms from
ALARM or TRIP event.
Pick-up
When a fault appears in the power system and some areas are disconnected, normally the remaining
generators connected to the network must supply the area disconnected from the utility side supply.
This results in an instantaneous demand of power that the generators must tackle. The
excitation and the mechanical systems cannot answer such a huge demand of power quickly even if
there were enough reserve power. The worst of the situation is received by the rotors of the generator
units: they suffer a torsion torque that can even break the rotor and cause subsequent damage not only
for the generator but for the entire power plant too.
A AQ Q-F213 -F213
Instruction manual
Version: 2.04
324