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Functions, monitoring and protective functions
9.3 Drive functions
9.3.3
Fast magnetization for induction motors
Description
Fast magnetization for induction motors reduces the delay time when magnetizing.
This shorter delay time is required for applications where a change is frequently made
between various motors and one converter. After being switched to a different motor, a new
data set must be loaded in the converter and then the motor magnetized. This can result in
excessive waiting times, which can be significantly reduced by means of quick
magnetization.
Features
● Rapid flux build-up by impressing a field-producing current at the current limit, which
considerably reduces the magnetization time.
● If the "Flying restart" function is activated, the excitation build-up time set in p0346 is still
used.
Commissioning
Parameter setting p1401.6 = 1 is necessary to activate fast magnetization.
This setting initiates the following sequence during motor starting:
● The maximum excitation build-up current of the induction motor (referred to the permitted
rated power module current (r0207[0])) is set with parameter p0644 (Current limit
excitation build-up induction motor).
● The field-generating current setpoint jumps to the value set in p0644 or the maximum of
Imax = 0.9 x r0067 (high limit field-generating current setpoint).
● The flux increases as fast as physically possible with the specified current.
● The flux setpoint r0083 is made to follow accordingly.
● As soon as the flux threshold value programmed in p1573 is reached (min.: 10%, max.
200%, factory setting: 100%), excitation ceases and the speed setpoint is enabled. The
flux threshold value must not be set too low for a large load because the torque-
producing current is limited during magnetization.
Note
Influence of the flux threshold value
The flux threshold value set in parameter p1573 is effective only if the actual flux during
magnetization reaches the value programmed in p1573 before the timer set in p0346
runs down.
516
Operating Instructions, 12/2018, A5E36652151A
Enclosed Drives
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