Configuration
Parameter manual b maXX BM3000
Document no.: 5.12001.07 Baumüller Nürnberg GmbH
102
of 820
4.4
130.13 Interior temperature warning threshold
Warning threshold for the internal temperature of the device. If the temperature exceeds
this threshold, the corresponding warning is generated.
130.15 PWM frequency
The PWM Frequency of the drive controller and the cycle time of the current controller are
set in this parameter.
Valid values:
Generally:
m The band width of the current controller is inversely proportional to the current control-
ler cycle time.
m The noise of the motor caused by the voltage signals in pulse form, drops with an in-
creasing PWM frequency.
m The thermal loading in the IGBT model decreases along with falling PWM frequency.
Therefore the attainable peak current length increases with falling PWM frequency at
constant peak current while the nominal current of the device increases during contin
-
uous operation.
m The adjusting range of the output frequency increases if the current controller cycle
time sinks. This adjusting range refers to the stationary operation and to the linear
range of the PWM - that means without an overmodulation and provides frequencies
that generate excellent output voltages.
n The quality of the generated output voltages is given by how close they are to the
effects of ideal sine voltages and depends on the ratio current controller frequency
f
I-R
(f
I-R
= 1/current controller cycle time) to the maximum output frequency f
max
:
f
max
= f
I-R
/ K
pf
. The greater the proportional factor K
pf
the better the quality is which
PWM Frequency Current controller cycle time
2 kHz 250 µs
4 kHz 125 µs
8 kHz 62,5 µs
16 kHz 62,5 µs
NOTE!
If it is intended to operate a PWM frequency of 2 kHz at an axis unit, it first must be
checked if the operation of the drive is permitted (e.g. if the related values of the mo
-
tor, or of the motor filter if one is at use, still are valid for this PWM frequency). At a
switching frequency of 2
kHz the current controller cycle time is 250 µs - so the ad-
justing range of the output frequency is 0 to 225 Hz (see the electrical data in the in-
struction handbook of the device).
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