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Table 7-3: List of velocity loop parameters
Panel
address
Internal
address
Name
Description
Default
Range
60F901
Kvp[0]
Proportional velocity loop gain
Can be displayed in Hz in the PC tool can if the
inertia ratio is right.
/
1-32767
d2.01
2FF00A
Velocity_BW
Changing this parameter changes kvp[0] by the
inertia ratio.
/
1-700
60F902
Kvi[0]
Integral velocity loop gain
/
0-1023
60F907
Kvi/32
Integral velocity loop gain of in a smaller unit of
measure
/
0-32767
d2.02
2FF019
Kvi_Mix
Writing this parameter sets kvi[0] to 0, and the
value is set to kvi/32.
/
0-16384
d2.05
60F905
Speed_Fb_N
Used to set Velocity feedback filter bandwidth
Filter bandwidth=100+Speed_Fb_N*20
25
0-45
d2.06
60F906
Speed_Mode
Used to set the velocity feedback mode
0: 2nd order FB LPF
1: Directly feedback the original velocity
2: Velocity feedback after velocity observer
4: Velocity feedback after 1
st
order LPF
10: Velocity feedback after 2
nd
order LPF and the
velocity command is filtered by a 1
st
order LPF. Both
filters have the same bandwidth. 11: The velocity
command is filtered by a 1
st
order LPF
12: Velocity feedback after velocity observer, the
velocity command is filtered by a 1
st
order LPF
14: Velocity feedback after 1
st
order LPF and the
velocity command is filtered by a 1
st
order LPF. Both
filters have the same bandwidth
1
/
60F915
Output_Filter_N
A 1
st
order lowpass filter in the forward path of the
velocity loop
1
1-127
60F908
Kvi_Sum_Limit
Integral output limit of the velocity loop
/
0-2^15
Velocity feedback filter adjustment
The velocity feedback filter can reduce noise that comes from the feedback path, e.g. reduce encoder
resolution noise. The velocity feedback filter can be configured as 1
st
and 2
nd
order via the Speed_Mode for
different applications. The 1
st
order filter reduces noise to a lesser extent, but its alsoresults in less phase
shifting so that velocity loop gain can be set higher. The 2
nd
order filter reduces noise to a greater extent,
but its also results in more phase shifting so that velocity loop gain can be limited.
Normally, if the machine is stiff and light, we can use the 1st feedback filter or disable the feedback filter. If
the machine is soft and heavy, we can use the 2
nd
order filter.
If there’s too much motor noise when velocity loop gain is adjusted, velocity loop feedback filter parameter
Speed_Fb_N can be reduced accordingly. However, velocity loop feedback filter bandwidth F must be more
than twice as large as the velocity loop bandwidth. Otherwise, it may cause oscillation. Velocity loop
feedback filter bandwidth F=Speed_Fb_N*20+100 [Hz].
