Field Regulator - Santerno DCREG2 Series User Manual

DCREG2
DCREG4
6.7

FIELD REGULATOR

DCREG2 and DCREG4 drives are equipped with an internal field regulator that may be used both to set a
field current fixed value and for a dynamic regulation in field weakening mode.
In both cases, the field current reference displayed in par. M017 (RefFld), so the relevant current, may be
assigned the values shown in the figure below.
RefFld
(M017)
n0
C010  C017
C010
n0
C010  C016
C010  C014
Stand-by + Economy
Economy
First case. The dynamic field regulation in field weakening mode is not required. The nominal field
current is set in parameter C010 (IfidNom).
As soon as the run command is sent and for the time set in par. C018 (FldFrcTime) the field forcing
function may be enabled, which increases the field current by the value per cent set in par. C017
(FldFrcLevel) in order to have a temporary torque boost. This will have no effect if the field flux is
saturated. The field forcing will be always disabled, also when the time set in par. C018 is not yet over, if
the armature voltage reaches approx. 66% of the value programmed in par. C030 (VmainsNom).
Once the drive run is over, the economy function may be enabled. This function allows the field current
to be decreased by the value per cent set in par. C014 (FldEcoLevel) as soon as the drive run is over and
once the delay set in par. C015 (FldEP/Nlay) is over. This may be useful when an energy saving function
is needed or when the motor temperature is to constantly exceed a min. value (anticondensate function).
If a min. speed of rotation is detected when the drive is not running (motor pulled), the field current will be
brought to the nominal value set by par. C010.
Second case. Another typical use of the field regulator is the dynamic regulation in field weakening
mode depending on the speed change. This may be used to control DC motors designed for operating in
the two constant available max. torque / power sections. Of course, said function may be mixed with the
others.
This operating mode may be used both when a relatively large torque is needed (at a low speed) and
when a relatively high max. speed is needed (but with a smaller torque), as for winders or unwinders in
tension control.
Varm<C0300.66
VarmC0300.66
Run + Forcing Run
C018
USER MANUAL
n0
n0
by Stand-by + Economy
Stand-
Economy
C015
103/200
15P0059B3
t