Danfoss VLT5000 SyncPos User Manual

Programmable SyncPos motion controller
MG.10.J8.02 – VLT is a registered Danfoss trade mark
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12 KDER (703)
The
Derivative factorDerivative factor
Derivative factorDerivative factor
Derivative factor KDER is the correction factor
with which the changing speed of a motor position
error is evaluated.
The derivative factor works against the tendency to
overswing due to a high proportional share and
'dampens' the system. However, if the derivative
factor selected is too large this will lead to a
'nervous' drive.
Content
Derivative value for PID control
Parameter Group
Axis parameter PID-Controller AXR
CAM-Editor: index card PID
Value range
0 … 65000 ★ 0
13 KINT (704)
The
InteInte
InteInte
Inte
gral Factorgral Factor
gral Factorgral Factor
gral Factor KINT is the weighting factor, with
which at time n the sum of all motor position errors
are evaluated.
The integral factor of the PID filter causes a corre-
sponding corrective motor torque which increases
over time. Through the integral share a static posi-
tion error is reduced to zero, even if a constant load
is affecting the motor.
However, an integral factor which is too large leads
to a 'nervous' drive.
Content
Integral value for PID control
Parameter Group
Axis parameter PID-Controller AXR
CAM-Editor: index card PID
Value range
0 … 65000 ★ 0
14 T I M E R
The TIMER parameter determines the sampling time
of the control algorithm.
For example, increase the value of the factory
settings
• for very low pulse frequency, such as from 1 to
2 qc per sampling time. You need at least 10 to
20 qc per sampling time.
• Or for very slow systems with a long dead time.
If 1 ms is used here for control, large motors
will vibrate.
Content
Sampling time for PID control
Parameter Group
Axis parameter PID-Controller AXR
CAM-Editor: index card PID
Unit
msec
Value range
1… MLONG ★ 1
Accordingly, the value should not be set
higher than 1000 (= 1 s). This would be
a very slow control.
NB!
Note that is has a direct effect on the PID
loop e.g. if you double the TIMER the KPROP
(11) has twice the effect.
Parameter Reference

Danfoss VLT5000 SyncPos Specifications

General

Category	Controller
Frequency	50/60 Hz
Series	VLT5000
Control Method	Vector control
Communication	CANopen
Enclosure Rating	IP20
Storage Temperature	-25°C to 70°C
Altitude	Up to 1000m above sea level
Humidity	5% to 95% (non-condensing)