Rockwell Automation Allen-Bradley Kinetix 5100 - Page 223

Rockwell Automation Publication 2198-UM004D-EN-P - December 2022 223
Chapter 9 Tuning
Timing Diagrams
ID189 (P2.004) VelocityProportionalGain [KVP]
This parameter determines the response of velocity loop. The larger the KVP
value, the higher the response frequency of the velocity loop and the lower the
velocity error. However, if you set the value too high, it could cause instability.
Typically, the response frequency of the velocity loop must be 4…6 times higher
than the response frequency of the position loop; otherwise, instability can
occur. The calculation of velocity loop frequency response is as follows:
JM= Motor Inertia; JL: Load Inertia; ID144 (P1.037): 0.1 (times)
When ID144 (P1.037) (auto estimation or manually set value) is equal to the real
inertia ratio (JL / JM), the real velocity loop frequency response is:
Impact of Speed Proportional Gain (KVP) Setting
The higher the KVP value, the larger the bandwidth, and
the speed increase time also shortens. However, if the
value is set too high, the phase margin is too small. The
effect is not as good as KVI for the steady-state error
but is better for the effect on following.
Impact of Speed Integral Gain (KVI) Setting
The higher the KVI value, the larger the low frequency
gain. It shortens the time for the steady-state error to
reduce to zero. However, it does not significantly reduce
the following error.
Impact of Acceleration Feedforward Gain (KVF) Setting
The closer the KVF value is to 1, the more complete the
forward compensation. The following error becomes
very small. But a KVF value that is set too high also
causes vibration.
fv
KVP
2
-----------


1 P1.03710+
1
JL
JM
-------
+
--------------------------------------




Hz=
fv
KVP
2
-------------


Hz=