
Rockwell Automation Publication 2198-UM002E-EN-P - February 2018
333
Motor Control Feature Support
Appendix D
Stability Control for
Frequency Control
Stability control is available for induction motors configured for frequency
control. This feature can be used to help remove resonances that are sometimes
seen on larger motors. The stability control feature adjusts the
OutputFrequency and OutputVoltage commands to stabilize the
OutputCurrent.
Figure 164 - Effects of Stability Control
Stability control for frequency control is not enabled by default. You can enable
via messaging by using the following device-specific attributes.
Table 156 - Enable Current Limiting via Messaging
Id
F
eed
ba
ck
, I
q
Fe
ed
ba
ck
A-
pk
Id Feedback, Iq Feedback versus Commanded Speed with Stability Control Disabled
Id Feedback, Iq Feedback versus Commanded Speed with Stability Control Enabled
Commanded Frequency, Hz
Iq Feedback
Id Feedback
60
50
40
30
20
10
0
-10
-20
25
20
15
10
5
0
-5
Id
Fe
ed
ba
ck
, I
q Fe
ed
ba
ck
A
-p
k
Commanded Frequency, Hz
Iq Feedback
Id Feedback
TIP
We recommend you leave the angle, voltage gains, and filter bandwidth at
the default values.
Attribute
Offset
Type
Attribute Name
Conditional
Implementation
Description
3026
SINT
Stability Control
Enable
Frequency Control
Induction Motor only
Enables stability control when configured for frequency control.
0 = Stability Control is disabled
1 = Stability Control is enabled
3027
REAL
Stability Filter
Bandwidth
Sets the bandwidth of the low-pass filter applied to the current feedback signal. This bandwidth is
common to both the angle and voltage stability control algorithms. Units of radians/second.
3028
REAL
Stability Voltage
Gain
The gain of the voltage stability control function. Only active when configured for frequency control.
Units of Volt (inst,p-n)/Amp (inst).
3029
REAL
Stability Angle Gain
The gain of the electrical angle stability control function. Only active when configured for frequency
control. Units of radians/Amp (inst).
IMPORTANT
Because the stability control feature works by manipulating the
OutputVoltage and OutputFrequency signals, these signals may appear
'noisy' when the feature is enabled.