gefran VDI100 Series

Figure4.4.122Speedlimitsetting
Output torque (T)
21-04 21-04
Torque reference (Tref)
Motor speed (N)
-100%
100%30%-30%
Effective range of torque control
‧Set speed limit value (21-03)=0
speed limit bias (21-04)=30%
‧The speed range of the torque Control is
from –30% to 30% of maximum output frequency.
Example 2:
Settings: 1. Speed limit value (21-03) =100% (positive speed limit)
2. Speed limit bias (21-04) = 20%
The speed range in torque control is from -20% (21-04) to 120% (21-03+21-04)
Figure4.4.123Speedlimitsetting(Example2)
Torque
Limit
Torque reference (Tref)
21-04
Motor speed
Torque Limit
100%
120%
-20%-100%
effective range
of torque control
Speed limit
(21-03) setting
‧When the speed exceeds the reverse speed limit(- 20%),
the torque is increased in the positive direction and is limited
by the regenerative torque limit in the 2nd quadrant.
‧When the speed exceeds the forward speed
limit(120%), the torque is increased in the
negative direction and is limited by the
regenerative torque limit in the 4th quadrant.
Output torque
Example: Torque limit and speed limit operation:
In this example the torque limit and speed limit are used in a winding and unwind operation.
Winding operation
The line speed (N) and motor torque (T) are in the same direction of the motor. Refer to Figure 4.4.124
Figure4.4.124Windingoperation
Torque
Limit
21-08
Output torque
(T)
Tref
Motor speed (N)
Torque Limit
21-07
21-04
21-04
Speed
Limit
Setting
M
Line direction
N
T



(1) Speed limit bias (-21-04) > Motor Speed > speed limit bias (+21-04) → torque based on Tref.
(2) Motor speed (N) > speed limit bias +21-04 → speed limit will output negative torque to prevent the increase
of motor speed.
(3) Motor speed (N) <-21-04 → speed limit will output a forward torque to prevent an increase of speed.
Unwinding operation
The line speed (N) and motor torque (T) are in opposite direction
VDI100 • Instruction manual 273