Siemens SINAMICS G150 Operating Instructions Manual page 497

occurs. Once the frequency has been found, the motor is magnetized. The output voltage
during the magnetization time (p0346) is increased to the voltage value yielded from the
V/f characteristic (see "Flying restart").
● Vector control without encoder:
The motor speed is determined using the speed adaptation control loop for the electric
motor model. To begin with, the search current (p1202) is injected and then the controller
is activated starting from the maximum search frequency. The dynamic response of the
controller can be altered using the search speed factor (p1203). If the deviation of the
speed adaptation controller is not too great, the motor continues to be magnetized for the
duration parameterized in p0346.
Once the excitation build-up time (p0346) has elapsed, the ramp-function generator is set to
the actual speed value and the motor ramped up to the current setpoint frequency.
Figure 9-6
Danger to life as a result of unexpected motor movement when activating flying restart
When the flying restart (p1200) function is active, the drive may still be accelerated by the
search current despite the fact that it is at standstill and the setpoint is 0!
For this reason, death, serious injury, or considerable material damage can occur if
personnel enter the working area of a motor in this state.
• Observe the general safety instructions.
• Ensure that the EMERGENCY STOP functions are always fully functional.
Note
Flying restart without encoder for permanently-excited synchronous motors
The flying restart without encoder for permanently-excited synchronous motors is possible
only when a VSM10 Voltage Sensing Module is used to acquire the motor speed (option
K51).
Converter cabinet units
Operating Instructions, 07/2016, A5E03347396A
Flying restart
WARNING
Functions, monitoring, and protective functions
9.2 Drive functions
497