Flying Restart - Siemens SINAMICS S120 Function Manual

Vector control

4.16 Flying restart

Overview of key parameters (see SINAMICS S List Manual)
● p0325 Motor pole position identification current 1st phase
● p0329 Motor pole position identification current
● p1780.6 Selects pole position identification PEM without an encoder (sensorless)
● p1980 Pole position identification technique
● p1982 Pole position identification technique
● r1984 Pole position identification angular difference
● r1985 Pole position identification saturation curve
● r1987 Pole position identification trigger curve
● p1999 Angular commutation offset calibration, scaling
4.16 Flying restart
Description
After power ON, the "flying restart" function switches automatically to a Motor Module that
may be coasting.
The "Flying restart" function should be activated via p1200 for an overrunning load. This
prevents sudden loads in the entire mechanics.
With an induction motor, the system waits for a demagnetization time to elapse before the
search is carried out. An internal demagnetization time is calculated. A time can also be
entered in p0347. The system waits for the longer of the two times to elapse.
In operation without an encoder, a search is carried out initially for the current speed. The
search starts at the maximum speed plus 25%. A Voltage Sensing Module (VSM) is required
for permanent-magnet synchronous motors for additional information, refer to the Equipment
Manual.
When operated with an encoder (speed actual value is sensed), the search phase is
eliminated.
For an induction motor, immediately after the speed has been determined, magnetization
starts (p0346).
The current speed setpoint in the ramp function generator is then set to the current actual
speed value.
The ramp-up to the final speed setpoint starts with this value.
Application example: After a power failure, a fan drive can be quickly reconnected to the
running fan motor by means of the flying restart function.
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Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
Drive Functions