ComAp IG-NT, Installation Manual

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IGS-NT Installation Guide
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16. Regulation loops
There are following regulation loops bulit-in in the controller. All of them are PI type except
angle loop, which is P type.
Frequency loop
The frequency loop is active in the first phase of
synchronization when the generator frequency is regulated to
match the mains/bus frequency. This loop can be also active
while the gen-set is running without load at nominal speed
and/or in single-island operation. See the setpoint
Freq Reg
Loop
Angle loop
The differential angle control loop is active during the
synchronization when the "near to zero" slip frequency has
been successfuly achieved and then the differential angle
between generator and mains/bus voltage shall be controlled
to the value adjusted by the setpoint
GtoM AngleReq .
Load control loop
This regulation loop is active when single gen-set is running in
parallel with mains and during load transfers from mains to
generator or vice versa.
This regulation loop is also active when multiple gen-sets are
running in parallel with mains when InteliMains NT is not in
charge and it is also active in multiple-parallel operation if the
load is controlled from an IM-NT (i.e. the setpoint
#SysLdCtrl
PtM is in LDSHARING position).
Load sharing loop
The load sharing loop is active in multiple-island operation
(while the input
MCB feedback is not active).
This loop is also active (using P,I factors multiplied by 0.1) on
the "background" while load sharing is beeing performed
(multiple-island operation) to maintain the group frequency at
nominal value.
This regulation loop is also active if the gen-set is running in
multiple island mode, however it is running in local baseload
mode instead of load sharing.
Voltage loop
The voltage control loop is active during synchronization (the
generator voltage is matched to the mains/bus voltage - see
the example below) and during the island operation in SPtM
(the gen-set voltage is maintained at the nominal voltage).
Example:
GenNomV is set to 220V and MainsNomV is set to 230V.
During the synchronization measured voltage on Mains/Bus is
235V. Controller regulates the generator voltage to the