Siemens SINAMICS S150 NEMA, Operating Instructions Manual

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Functions, monitoring and protective functions
9.3 Drive functions
Enclosed Drives
528
Operating Instructions, 12/2018, A5E36652151A
9.3.6.1 Flying restart without encoder
Description
Depending on parameter p1200, the flying restart function is started with the maximum
search speed n
Search,max
once the de-excitation time (p0347) has elapsed (see diagram
"Flying restart").
n
Search,max
= 1.25 x n
max
(p1082)
The flying restart function behaves differently with V/f control and vector control:
● V/f characteristic (p1300 < 20):
The search speed yielded from parameter p1203 reduces the search frequency in
accordance with the motor current. The parameterizable search current (p1202) is
injected here. If the search frequency is similar to the rotor frequency, a current minimum
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 Flying restart