Method 2: characteristic curve for asynchronous drive characteristic
Asynchronous motors are frequently used for spindle drives. By means of the speed-dependent spindle accleration a= f(n) shown in the following figure, users can achieve optimum adaptation to the typical characteristic of the spindle motor.
Besides the maximum permitted acceleration, a_max, speed N1 for the constant acceleration range, only a further parameter N2 and the high minimum acceleration a_min needs to be parameterized. Acceleration is constant up to the speed N1. Above N1, acceleration is proportional to 1/n, and above N2 it is proportional to 1/n2.
Example characteristic
N1=10000 degrees/s
N2=20000 degrees/s
a_max=16000 degrees/s
As from the nominal speed (nlimit) the characteristic profile is as follows:
Parameters
P-AXIS-00202 | Characteristic type 3: asynchronous drive |
P-AXIS-00010 | Minimum acceleration amin |
P-AXIS-00240 | Maximum acceleration amax for n<N1 |
P-AXIS-00241 | Speed limit N1 for maximum torque |
P-AXIS-00242 | Speed limit N2 for maximum output |
Parameterization example
getriebe[0].beschl_kennlinie.typ 3 Asynchronous operation
getriebe[0].beschl_kennlinie.a_max 16000 [°/s²]
getriebe[0].beschl_kennlinie.a_min 4000 [ ° /s*s]
getriebe[0].beschl_kennlinie.n1 10000000 [10-3 °/s]
getriebe[0].beschl_kennlinie.n2 20000000 [10-3 °/s]