Vacon apfiff09 marine, Applications Manual

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apfiff09 marine VACON®
•
193
Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/
Classified as Public
Set then the midpoint voltage to

2 * Zero Point Voltage
and
the midpoint frequency to (Zero Point Voltage/100%)*Nominal frequency of motor)
Step 2 (If needed): Activate speed control or U/f optimization (Torque boost).
Step 3 (If needed): Activate both speed control and U/f optimization.
NOTE! In high torque
–
low speed applications
–
it is likely that the motor will
overheat. If the motor has to run long times under these conditions,
special attention must be paid to cooling of the motor. Use external
cooling for the motor if the temperature tends to rise too high.
P2.8.4.1 U/f optimisation ID109
“U/f Optimization”
Automatic
torque
boost The voltage to the motor changes proportionally to required torque
which makes the motor produce more torque at start and when running
at low frequencies. Automatic torque boost can be used in applications
where starting torque due to starting friction is high, for example, in
conveyors. Even with linear U/f curve, the torque boost has an affect
but the best result will be achieved after the identification run when
programmable U/f curve is activated.
P2.8.4.2
U/f ration selection ID108
“U/f Ratio Select”
Linear:
0
The voltage of the motor changes linearly from zero point voltage to the
field weakening point where the voltage at FWP is supplied to the motor.
Squared:
1
The voltage of the motor changes from zero point voltage following the
squared curve form zero frequency to the field weakening point. The motor
runs under magnetised below the field weakening point and produces less
torque. Squared U/f ratio can be used in applications where torque de-
mand is proportional to the square of the speed, for example, in centrifugal
fans and pumps.
Programmable U/f curve:
2
The U/f curve can be programmed with three different points.
1. Zero point voltage
2. Midpoint frequency and Midpoint voltage.
3. Field weakening point and field weakening point voltage.
Programmable U/f curve can be used if more torque is needed at low
frequencies. Make the Identification run for optimal setting (ID631).
Linear with flux optimisation:
3
The AC drive starts to search for the minimum motor current in order to
save energy. This function can be used in applications with constant motor
load, such as fans, pumps etc.
P2.8.4.3 Field weakening point ID602
“Field WeakngPnt”
The field weakening point is the output frequency at which the output voltage reaches the
field weakening point voltage.