ABB RELION REX640 - Fuel rack position monitoring

Type of fault Fault detection criteria
Output
activation
(Check if the local reactive power (Q) is deviating
significantly from other generators in the same net-
work)
Under excitation
fault
Number of generators in parallel with same gover-
nor mode >= 3
AND
MAX(Q1, Q2, … Q8) – MIN(Q1, Q2 … Q8) < Max Q Dev
Vot
AND
Q < MIN(Q1, Q2 … Q8) -
Max Q Dev Vot
UN_EXCT_FLT
Among the 8 reactive power inputs, Q1 … Q8, the input corresponding
to the setting Local generator Num , would be considered as the local
reactive power. For example, if Local generator Num is set to "1", then Q1
is considered as the local generator reactive power output.
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 Figure 801 , is
assumed between the fuel rack position and the generator active power.
The droop characteristics can be parameterized using the settings Rack Pos no load
and Rack Pos gain . If the performance of the generator set deviates over/under
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 Disable
Fuel Rck Mon
.
1MRS759142 F
Condition monitoring functions
REX640
Technical Manual
1415