Rocof Protection - ABB SACE Emax E1.2 Operating Instructions For The Design Engineer

ROCOF Protection

t
f28
ROCOF
t28
Hz/s
97 | © 2017 ABB | 1SDH001330R0002 - ECN000058721 Rev. A
Path
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Function
ROCOF protection protects against rapid frequency variations.
When the frequency change exceeds the control threshold f28 over time, the protection trips within a fixed
time t28.
It is also possible to characterize the protection according to the way in which frequency varies (increase or
decrease), or to consider both conditions.
f(Hz)
Figure 25
NOTE: the protection is not active for voltages <30V.
Parameters
It is possible to modify various parameters:
Parameter Description
Enable To activate/deactivate the protection.
It defines the maximum allowed frequency variation rate over time, above which
Threshold f28 the protection will be activated.
It is represented as an absolute value (Hertz / second).
It defines whether the protection monitors increases, decreases, or both
Trip Direction
variations.
This is the delay time between the exceeding of the f28 threshold and the
Time t28
sending of the opening command
ROCOF protection has StartUp enable, see page 71.
Via Ekip Connect it is also possible to access the blocking functions, see page 72.
frequency
after failure
failure
50/60 Hz
frequency
after failure
Ekip Touch protection trip unit | 13 - G Hi-Touch protections
ABB | SACE Emax 2
Time