ABB RELION REX640 Technical Manual page 1415

1MRS759142 F
Type of fault
Under excitation
fault
Fuel rack position monitoring
This module compares the position of the engine's fuel rack, obtained as input
FUEL_RCK_POS, to the active power, P. The FUEL_RCK_POS input is a 0-20mA signal
obtained through an RTD input. An offset linear relationship, refer
assumed between the fuel rack position and the generator active power.
The droop characteristics can be parameterized using the settings
and
the set droop curve, the fuel rack system is identified as faulty and the output
FUEL_RCK_FLT is activated. The module can be disabled using the setting
Fuel Rck Mon .
REX640
Technical Manual
Fault detection criteria
(Check if the local reactive power (Q) is deviating
significantly from other generators in the same net-
work)
Number of generators in parallel with same gover-
nor mode >= 3
AND
MAX(Q1, Q2, ... Q8) – MIN(Q1, Q2 ... Q8) <
Vot
AND
Q < MIN(Q1, Q2 ... Q8) -
Among the 8 reactive power inputs, Q1 ... Q8, the input corresponding
Local generator Num , would be considered as the local
to the setting
reactive power. For example, if
is considered as the local generator reactive power output.
Rack Pos gain . If the performance of the generator set deviates over/under
Condition monitoring functions
Max Q Dev
Max Q Dev Vot
Local generator Num is set to "1", then Q1
Output
activation
UN_EXCT_FLT
Figure 801
, is
Rack Pos no load
Disable
1415