2 - Fagor Automation

T. H5/3 Different accelerations depending on speed.
Method Different accelerations depending on speed
Control Linear acceleration avoiding abrupt variations in
transmitted torque.
Comment
Emulation of the square sine function for speed by
using ramps.
Limited acceleration and choke. Choke = (acceleration / t).
F. H5/10
Acceleration and choke limit.
T. H5/4 Acceleration and choke limit.
Method Acceleration and choke limit.
Control
Progressive linear acceleration, avoiding abrupt variations
of transmitted torque.
Comment
Approach square sine function (bell shape) for the
speed.
The capability demanded from the motor is determined by the following
formulas:
Capacity required by the motor
in the constant torque area:
(0 < N M < N B )
Capacity required by the motor
in the constant torque and constant
power area:
(0 < N M < N max )
0
speed
adjust
JM Inertia of the load in kg·m² as viewed from the motor shaft
PN Rated power at base speed kW
Nmax Maximum motor speed in rev/min.
NB Motor base speed in rev/min.
NM Motor speed reached after a time period t in rpm
t Acceleration time until NM (in seconds) is reached
P N
P N
2
------
60
2 JM N M
= ------------------- kW 1000 t
We will now give several examples of calculations using a mechanical
specifications and for a standard motor. The results could vary from real
ones through mechanical losses, fluctuations in mains voltage, or inaccuracies
of mechanical data.
Example.
Data:
Acceleration time:
Between 0 and 1500 rpm in 0.5 s. (1)
Between 0 and 6000 rpm in 2.5 s. (2)
Motor inertia: Jmotor = 0.13 kg·m²
Motor base speed: Nb = 1500 rev/min
2
2 2
NB
Selection criteria
time
2
------
60
2 JM N M +
=
-------------------------------------- kW 2000 t
SELECTING CRITERIA
Asynchronous spindle motor and servo drive selection 5.
DDS
HARDWARE
Ref.1307
215