Motor Control - ABB ACS380 Firmware Manual

ACS380 FW.book Page 340 Friday, May 4, 2018 4:18 PM
340 Parameters
No. Name/Value

97

97 Motor control

97.01 Switching frequency
reference
4 kHz
8 kHz
12 kHz
97.02 Minimum switching
frequency
1.5 kHz
2 kHz
4 kHz
8 kHz
12 kHz
97.03 Slip gain
0...200%
97.04 Voltage reserve
-4...50%
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Description
Switching frequency; slip gain; voltage reserve; flux
braking; anti-cogging (signal injection); IR compensation.
Defines the switching frequency of the drive that is used
as long as the drive does not heat too much. See section
Switching frequency on page 79.
Higher switching frequency results in lower acoustic
noise.
In multimotor systems, do not change the switching
frequency from the default value.
4 kHz.
8 kHz.
12 kHz.
Lowest switching frequency that is allowed. Depends on
the frame size.
1.5 kHz. In some larger frame sizes 1 kHz is used instead. 1.5
2 kHz.
4 kHz.
8 kHz.
12 kHz.
Defines the slip gain which is used to improve the
estimated motor slip. 100% means full slip gain; 0%
means no slip gain. The default value is 100%. Other
values can be used if a static speed error is detected
despite having the setting at full slip gain.
Example (with nominal load and nominal slip of 40 rpm):
A 1000 rpm constant speed reference is given to the drive.
Despite having full slip gain (= 100%), a manual
tachometer measurement from the motor axis gives a
speed value of 998 rpm. The static speed error is 1000
rpm - 998 rpm = 2 rpm. To compensate the error, the slip
gain should be increased to 105% (2 rpm / 40 rpm = 5%).
Slip gain.
Defines the minimum allowed voltage reserve. When the
voltage reserve has decreased to the set value, the drive
enters the field weakening area.
Note: This is an expert level parameter and should not be
adjusted without appropriate skill.
If the intermediate circuit DC voltage U
voltage reserve is 5%, the RMS value of the maximum
output voltage in steady-state operation is
0.95 × 550 V / sqrt(2) = 369 V
The dynamic performance of the motor control in the field
weakening area can be improved by increasing the
voltage reserve value, but the drive enters the field
weakening area earlier.
Voltage reserve.
Default
FbEq 16
4 kHz
4
8
12
1.5 kHz
2
4
8
12
100%
1 = 1%
-2%
= 550 V and the
dc
1 = 1%