Santerno Sinus Penta - Page 403

PROGRAMMING GUIDE
SINUS PENTA
403/486
Function
This parameter sets the type of implementation carried out by the PID regulator.
C294 = External Output:
The PID regulator is independent of the drive
operatio
n, unless a digital input is configured for PID disabling; if the digital input
closes, the PID regulator is disabled and the output is set to zero. In order to
use the PID regulator output externally to the drive
, configure one of the analog
outputs as PID Out.
C294 = Reference:
The PID regulator output is the speed/torque reference of
the connected motor (depending on the type of reference configured when the
motor is running); any other reference source which will be selected will be
ignored. If the outp
ut is a speed reference, 100% corresponds to the max.
absolute value between min. speed and max. speed set for the motor being
used.
Mot1 <– Max { | C028 |; | C029 | }
Mot2 <– Max { | C071 |; | C072 | }
Mot3 <– Max { | C114 |; | C115 | }
If the output is a torque reference, 100% is
the max. absolute value between the
min. limit and the max. limit of the torque of the active motor.
Mot1 <– max { | C047 |; | C048 | }
Mot2 <– max { | C090 |; | C091 | }
Mot3 <– max { | C133 |; | C134 | }
C294 = Add Reference:
The PID regulator output is a correction of the
speed/torque reference of the active motor (depending on the type of reference
configured when the motor is running). The percentage value of the PID output
relates to the instant value of the speed/t
orque reference. For example, if the
speed reference of the active motor is 800rpm and the PID output is ignored, if
this drops to 50%, the overall speed setpoint will be 800 + 800*(50/100) =
1200rpm. Therefore, the PID regulator can never reversed the reference sign.
C294 = Add Voltage Out:
This configuration is active only when the control
algorithm of the active motor is IFD
. In this case, the PID regulator output is a
correction of the output voltage. The percentage value of the PID output relates
to the instant voltage value.
For example, if a motor is operating in IFD
mode and the drive output voltage is
200V rms at 25 Hz with PID Output = 0, if PID Output drops to -10%, the
actual
voltage will be 200 + 200*(–10/100) = 180V.
Another possible usage is
the voltage drop compensation on a filter (if any)
installed between the drive and the motor. To do so, set (C285, C286, C287
) 9:
Vout as a reference, and (C288, C289, C290) 13: Vout measured
as a
feedback. Two properly transformed phases are to be linked
to analog inputs
AIN1 e AIN2
downstream of the filter, in order to exploit the voltage actually
delivered to the motor as the feedback. Only when C285, C286 or C287
are set
to 9: Vout, the value percent of the PID output is referred to the nominal voltage.
See “Example of Compensation of Voltage Drop in a Filter
” at the end of this
section.
C294 = Add Reference Full:
The regulator output is a correction of the
speed/torque reference of the connected motor (depending
on the type of
reference configured for the active motor). The value percent
of the PID output
is managed in the same way as C294 = R
eference and is summed to the main
reference.
For example, if a motor is speed-controlled with C029=1500rpm
, considering
the PID regulator output as null, the reference is 400rpm; if the PID
output
becomes 50%, the total speed setpoint is 400 + 1500*(50/100) = 1150rpm.
In that way, if the PID output is other than zero, the reference generated will be
other than zero as well, even if the main reference is null, unlike what would
happen if C294 = Add Reference.
NOTE
If C294 = 0: External Output, it is not possible to set the PID reference from keypad in remote
mode, unless Keypad or UpDown from MDI is set as the PID reference for parameters C285,
C286, C287.