Delta ASD-A3-0121, User Manual

Page: 171 / 603

Operation Mode ASDA-A3
6-20
Revision December, 2017
6
6.3.6 Gain adjustment of the speed loop
The structure of the speed control unit appears in the following diagram:
Speed control unit
Gain
switching
P2.027
Torque
command
+
-
+
+
+
Low-pass filter
P2.049
Torque constant
reciprocal
1/KT
Current
command
Speed
estimator
Encoder
Motor inertia
JM
System inertia J
(1+P1.037)*JM
Rate of
change
P2.005
Integrator
+
+
Differentiator
Load inertia
P1.037
+
Gain switching
P2.027
Speed control
gain
P2.004
Feed forward
gain
P2.007
Speed integral
compensation
P2.006
In the Speed Control unit, you can adjust different types of gain. You can adjust the gain
manually or use the three gain adjustment modes provided.
Manual: you set values for all the parameter settings. Auto and auxiliary functions are disabled.
Gain Adjustment mode: please refer to Chapter 5 Auto tuning.
Manual mode
When you set P2.032 to 0, you also set the Speed Loop gain (P2.004), Integral Compensation
(P2.006), and Feed Forward gain (P2.007).
Speed Loop gain: the higher the gain, the larger the bandwidth for the speed loop response.
Integral Compensation gain: increasing this gain increases the low frequency rigidity and
reduces the steady-state error. However, the phase margin is smaller. If you set this gain too high,
you reduce the system stability.
Feed Forward gain: reduce the deviation of the phase delay.
Relevant parameters: refer to Chapter 8 for more information.
Parameter Function
P2.004 Speed control gain (KVP)
P2.006 Speed integral compensation (KVI)
P2.007 Speed feed forward gain (KVF)