Toshiba TOSVERT VF-AS1 Manual page 6

4-1-4. Adjusting the moment of inertia of the load (f462)
The parameter for the adjustment of the moment of inertia of the load is effective in preventing a rapid
change in acceleration during acceleration or deceleration.
When a machine with a high-inertia load is accelerated or decelerated, speed may overshoot the
specified limit because of a change in acceleration, especially at acceleration and deceleration stop
points.
The figures below show the relationship between the speed command during acceleration and the
setting of f462.
Overshoot
Speed
f462=0
If you want to operate a machine with a low-inertia load at the highest possible acceleration/deceleration,
you can increase the response by setting f462 to 0.
4-2. How to switch speed control gains
During high-speed or low-speed operation, speed cannot be changed in some cases without changing the
speed control gain for reasons of machine characteristics. In such cases, use this gain switching function.
Gains are switched from one to the other when the frequency set with f466 is reached, as shown in the
figures below.
f460 (Speed loop proportional gain)
f461 (Speed loop stabilization coefficient)
f462 (Moment of inertia of load 1)
f463 (Second speed loop proportional gain)
f464 (Second speed loop stabilization coefficient)
f465 (Moment of inertia of load 2)
f466 (Speed PI switching frequency)
Speed loop proportional gain
Speed loop stabilization coefficient
Moment of inertia of load 1
Operation frequency
Actual
speed
Speed
Speed
command
Time
*1
f460
f461
f462
f466
Speed
command
Speed
Actual
speed
Time
f462=35
Speed control gain 1
Speed control gain 2
f463
f464
f465
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Speed
command
Actual
speed
Time
f462=100
f460
Time
f461
Time
f462
Time
Time