Fast Magnetization For Induction Motors - Siemens SINAMICS G150 Operating Instructions Manual

9.2.3

Fast magnetization for induction motors

Description
Fast magnetization for induction motors reduces delay time during 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:
● Parameter p0644 ("induction motor excitation current limit") sets the maximum excitation
current of the induction motor (based on the permitted rated current of the power section
(r0207[0])).
● The field-forming current setpoint jumps to the value parameterized in p0644 or maximum
to Imax = 0.9 x r0067 (field-forming current setpoint upper limit).
● 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.
● The flux is increased further until the flux setpoint in p1570 has been reached.
● The field-producing current setpoint is reduced by means of a flux controller with P gain
(p1590) and the parameterized smoothing factor (p1616).
Converter cabinet units
Operating Instructions, 07/2016, A5E03347396A
Functions, monitoring, and protective functions
9.2 Drive functions
485