54 • vacon
ASFIFF12 High Speed
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1508
Voltage Stabilizer Damping Coefficient
Voltage stabilizer acts like the torque stabilizer preventing the speed from oscillating at
light loads. The voltage stabilizer prevents speed oscillations by damping especially the
DC-link voltage oscillations. The damping coefficient affects like the damping coefficient
in a torque stabilizer. The voltage stabilizer affects also directly the output frequency of
the drive.
1509
Voltage Stabilizer Gain
This parameter defines the voltage stabilizer gain at the light load. The gain is internally
reduced when the torque increases. The higher the gain the stronger effect the stabilizer
has. Too high gain may result in problems with stability.
The actual gain is zero if the motor torque is higher than 50% of motor nominal torque.
1510
Voltage Stabilizer Limit
This parameter sets the limit for the voltage stabilizer output frequency.
1511
Advanced Options 1
By changing the value of this WORD -type variable is it possible to activate different bits
of the Advanced Options1 variable.
Sel.
Advanced options 1
B0
Disable synchronous modulation
B1
Use encoder speed for slip compensation
B2
Disable encoder supervision
B3
Disable slip compensation for reverse direction
B4
Increase output frequency range up to 3900Hz
B5
Increment
1512
Synchronous / Asynchronous Modulation
In a synchronous modulation mode the ratio of the switching frequency and the drive
output frequency i.e. the pulse number is an integer.
1513
Symmetrical / Asymmetrical Modulation
In a synchronous modulation mode it is also possible to use the symmetrical modulation.
In this case, the ratio of the switching frequency and the drive output frequency i.e. the
pulse number is restricted to certain values so that the motor voltages are more
symmetrical and balanced. The actual switching frequency depends on the drive
frequency and may change in steps and drop much below the switching frequency set
value. Hence, there may be problems with motors having a sinus-filter, if too low
switching frequency set value is used.
1514 Low
Speed
Option
This parameter has to be connected off (= value -1) when running over 100-150Hz
otherwise may the motor operation go unstable. When running the motor under this
frequency, the value can be changed between 2000 and 3000.
In drives with internal optical communication link (Fr9 -> or Ch61 ->) it is recommended
to use 3000 and with other units value 2000
Both ID1514 and ID1515 have to be switched off when not in use.