Search Run - BONFIGLIOLI ACTIVE Cube ACU 201-01 Operating Instructions Manual

12.5

Search Run

The synchronization to a rotating drive is necessary in applications which drive the
motor by their behavior or in which the drive is still rotating after a fault switch-off.
Via
Operation mode search run
motor speed without an "Overcurrent" fault message. After this, the motor is acceler-
ated to the reference speed at the set acceleration. This synchronization function
determines the current rotary frequency of the drive via a search run in operation
modes 1 to 5.
The synchronization in operation modes 10 to 15 is accelerated by short test im-
pulses. Rotary frequencies of up to 175 Hz are determined within 100 ms to 300 ms.
For higher frequencies, a wrong frequency is determined and the synchronization
fails. In the "Quick synchronization" operation modes, the search run cannot deter-
mine whether a synchronization attempt has failed.
For operation of a synchronous motor, the flux direction can be determined in order
to prevent alignment of the motor shaft (jerking) during start-up. Determining the
flux direction takes approx. 20 ms. In this process, there are short torque pulses.
This method is not suitable for very dynamic drives since the torque pulses result in a
rotation of the drive and consequently in wrong measurements. Once the flux direc-
tion was determined, the flux is formed (Parameter
779,
Maximum flux-formation time
order to improve the starting behavior.
Operation mode 645
0 - Off
Search Dir. acc. to
1 - Preset Val.,
DCB
First clockw.
2 - then anticlockw.,
DCB
First anticlockw.
3 - then clockw.,
DCB
Clockw. only,
4 -
DCB
Anticlockw. only,
5 -
DCB
Quick Synchroniza-
10 -
tion
Quick Synch. acc. to
11 -
Preset Value
Quick synch.,
14 -
clockw. only
Quick synch.,
15 -
anticlockw. only
Operation modes 1, 4 and 5 define a direction of rotation for the search run and
avoid a deviating direction. The search run can accelerate drives by checking the
rotary frequency if the drives have a low moment of inertia and/or a small load mo-
142
645, the motor speed is synchronized to the current
780,
The synchronization to a rotating drive is deactivated.
The search direction is defined by the sign in front of the
reference value. If a positive reference value (clockwise
field of rotation) is entered, the search is in a positive di-
rection (clockwise field of rotation), with a negative refer-
ence value, the search is in a negative direction (anti-
clockwise field of rotation).
The first attempt is to synchronize to the drive in positive
direction (clockwise field of rotation). If this attempt fails,
it is tried to synchronize to the drive in negative direction
(anticlockwise field of rotation).
The first attempt is to synchronize to the drive in nega-
tive direction (anticlockwise field of rotation). If this at-
tempt fails, it is tried to synchronize to the drive in posi-
tive direction (clockwise field of rotation).
Synchronization to the drive is only done in positive di-
rection (clockwise field of rotation).
Synchronization to the drive is only done in negative
direction (anticlockwise field of rotation).
An attempt is made to synchronize to the drive in positive
direction (clockwise field of rotation) and in negative
direction (anticlockwise field of rotation).
The search direction is defined by the sign in front of the
reference value. If a positive reference value (clockwise
field of rotation) is entered, the search is in a positive di-
rection (clockwise field of rotation), with a negative refer-
ence value, the search is in a negative direction (anti-
clockwise field of rotation).
Synchronization to the drive is only done in positive di-
rection (clockwise field of rotation).
Synchronization to the drive is only done in negative
direction (anticlockwise field of rotation).
Operating Instructions ACU
Minimum flux-formation time
Current during flux-formation
Function
781) in
06/13