ABB RELION REX640 Technical Manual page 1411

1MRS759142 F
droop curve is set using the settings
sample droop characteristics and the associated settings are shown in
Figure 800: Frequency vs. Active power droop characteristics
When the input GOV_MOD_CDRP is active, then the central PMS shifts the droop
curve parallel to the existing curve, through inputs CDRP_F_SET. The CDRP_F_SET
input is a 0-20mA signal obtained through an RTD input, directly gives the no
load set point frequency for the generator, using which the droop characteristic
is generated. The calculated frequency limit at a particular load is displayed
in monitored data F_CALC_LIMIT. If the network frequency value deviates over/
under the F_CALC_LIMIT by a margin greater than set
OV_FUEL_FLT or UN_FUEL_FLT outputs are activated. When the generator is in
compensated droop mode and if the quality of the signal CDRP_F_SET is not
reliable, the module is disabled and INT_BLKD output is activated.
When input GOV_MOD_BASE is active, the local active power is compared to the
load set point received from PMS, BASE_P_SET. The BASE_P_SET input is a 0-20mA
signal obtained through an RTD input. If the local active power deviates from this
set point by a margin greater than the set
fueling fault. In case the quality of the signal BASE_P_SET is not reliable when
generator is in base mode, then the correlation module is disabled and INT_BLKD
output is activated.
Any one among the binary inputs from governor, for example, GOV_MOD_ISOC,
GOV_ MOD_DRP, GOV_MOD_CDRP and GOV_MOD_BASE can be active at a given time.
If more than one of them is active or if none of them is active, then the output
INT_BLKD is activated and the Correlation algorithm is stopped.
Table 1343
generator system. For simplicity, the local active power will simply be called P in the
tables below.
REX640
Technical Manual
Frequency (F)
F set point no load
indicates the method of detecting over/under fueling faults in a diesel
Condition monitoring functions
F set point no load and Frequency droop . A
Max Freq deviation
Active power (P)
Max Freq deviation , the
Max P Dev Crl , it indicates an over/under
Figure 800
Frequency
droop
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