Drive Configuration
Initial Setup of the Register Tree
motors with very low impedance (e.g. spindles)
pwm100kHz
can be considered to reduce the heat-
ing of the motor.
Kr
,
Tn
: These registers are used to configure the PI current controller. For initial configuration these
values can be set to zero. The setup and optimization of the current controller is described in sec -
tion 5.4.1.
IntegratorOutputLimit
: This parameter can be used to restrict the output of the integral term to
avoid a windup behavior of the controller. Typically this value is set to 0.5..1.0 of the
CurrentCon-
troller.OutputLimit
(see below)
R
,
L
,
Kt
: These parameters are the voltage feed forward with
R
representing the phase to phase re-
sistance,
L
for the phase to phase inductance and
Kt
is the back EMF constant of the motor. In most
cases it is recommended to set these parameters to zero, as voltage feed forward is not required
because of the high bandwidth of the current controller.
FeedForwardLimit
: Set this parameter to limit the feed forward voltage calculated by the
R
,
L
and
Kt
parameters. If
FeedForwardLimit
is set to zero, the feed forward path is disabled.
OutputLimit
: This parameter restricts the maximum output voltage over one phase. Typically this
parameter is set to the maximum possible voltage which depends on the available DC-bus voltage
and the
Motor.Type:
SynchronousAC
: The maximum setting is 0.577 times the dc-bus voltage.
DC
: In case of a DC-motor the
OutputLimit
can be set equal to the DC-bus voltage.
5.2.9 Axis[].Parameters.CurrentController.FieldWeakening
Field weakening is a method for increasing the speed of electrical motors if the DC bus voltage is the re-
stricting factor. This is accompanied by a reduction of the maximum torque of the motor. Field weaken-
ing with synchronous AC motors and Field Oriented Control is achieved by inducing a negative
i
D
current
depending on the speed of the motor. It is mainly applied to high speed spindles if the desired speed is
not reached.
VelocityStart
: This parameter determines the velocity above which the field weakening is applied.
Gain
: With the
Gain
the induced current
i
Dfw
is calculatd depending on the velocity according to the
following equation. To induce a negative
i
Dfw
the
Gain
has to be smaller than zero.
i
Dfw
=
{
Gain
⋅(
|
velocity
|
−
VelocityStart
)
if
|
velocity
|
>
VelocityStart
0
else
5.2.10 Axis[].Parameters.CurrentController.FeedForwardFilter
By default and for a first setup the
Type
of the filter should be set to
bypassed
to deactivate it. Refer to
Figure Figure 45 for more information.
5.2.11 Axis[].Parameters.Homing
This node can be used to configure a homing sequence executed by the drive. More information about
how to setup the homing of an axis is documented in [11].
Method
: For the initial setup of the axis no homing is required and the homing method is set to
None
.
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