Programming
Page
D-100
890CS Common Bus Supply - Frames B & D; 890CD Common Bus Drive and 890SD Standalone Drive - Frames B, C & D
8
9
10
A
B
C
D
E
1
2
3
4
5
6
7
Parameter Descriptions
ACTUAL PWM FREQ
PREF: 73.05
Default: —. Hz
Range: —. Hz
The actual pwm switch frequency applied to the motor.
This can reduce in overload conditions in all Control Mode, except PMAC Control Mode.
PWM FREQ PMAC
PREF: 73.11
Default: 0
Range: See below
This parameter defines the frequency of the PWM in PMAC Control mode
Enumerated Value
:
PWM FREQ PMAC
0 : 4 KHz
1 : 8 KHz
2 : OTHERS
OTHERS only available on V3.3 and higher. This is a way to allow the
selection of other values for FREQ SELECT when using a PMAC motor
with
an
ENDAT
encoder.
If selecting a PWM at 2 KHz is possible (you also need to modify/reduce the bandwidth of loops (current, speed and position)),
it must be reserved to specific applications where the larger 890 frames are used.
Functional Description
The Drive provides a unique quiet pattern PWM strategy in order to reduce audible motor noise. The user is able to select
between the quite pattern or the more conventional fixed carrier frequency method. With the quiet pattern strategy selected
(random pattern enabled), audible motor noise is reduced to a dull hiss.
In addition, the user is able to select the PWM carrier frequency. This is the main switching frequency of the power output
stage of the Drive. A high setting of carrier frequency (e.g. 6kHz) reduces audible motor noise but only at the expense of
higher Drive losses and smooth motor rotation at low output frequencies. A low setting of carrier frequency (e.g. 3kHz),
reduces Drive losses but increases audible motor noise.
