Siemens simovert masterdrives

Functions 09.2008
6SE7087-6QX70 (Version AK) Siemens AG
7-26 Compendium Motion Control SIMOVERT MASTERDRIVES
The AVWF, which is entered in P169 for the figured before the decimal
point and in P170 for the figures after the decimal point, can be entered
as a decimal with a maximum of 8 figures. Alternatively, the AVWF
parameters can be entered as a gearbox factor (fraction)
numerator/denominator, P180.1, P180.2 of the motor encoder.
The rated speed is a reference value used to represent speed.
The AVWF is also used to calculate the rated speed U656 which, in the
factory setting, is 12288.00 [1000 LU/Min]. If this value is changed, the
basic unit parameter P205 (rated V) must also be set to the same
value, ignoring the figures after the decimal point.
Rated V = resolution x AVWF factor x reference speed x 10
-3
Rated V: U856
Resolution: P171 [FD 330.3]
AVW factor: P169, P170 or P180, P181 [FD 330.3]
Reference speed: P353 [FD 20.5]
The rated V is specified in 1000 LU/min and the reference speed in
rpm.
In the factory setting, the resolution of 2
12
= 4096 increments/revolution,
an AVWF = 1.0 and 3000 rpm results in a rated speed of 12 288 000
LU/min. This speed then corresponds to 100% in the equipment.
In the example, the rated V derived from:
131 072 [LU/rev.], an AVWF of 0.71905288 [AVWF] and 3000 rpm
rated motor speed results in a rated speed of 282743097 [LU/min].
U856 = rated V = 2
17
x 0.71905288 [IBF] x 3000 [rpm] x 10
-3
= 282743.096 in 1000 LU/min
The value is entered in 1000 LU/min with 2 decimal places
= 282743.09 in 1000 LU/min
The acceleration represents the change of speed (LU/min) within a time
unit.
The rated acceleration is defined as the rate at which the drive
accelerates from v = 0 to the rated speed (rated V) in t = 1 sec.
The following equation is used to calculate this:
Rated acceleration = U857 (in 1000 LU/s
2
)
Rated speed = U856 (in 1000 LU/min)
t60
)856U( speed rated
onaccelerati atedr )857U(
×
=
NOTE
Rated speed (U856)
Rated acceleration
(U857)