Siemens SIMOVERT MASTERDRIVES Manual page 897

Engineering Information
5. Selection of the
inverter
=
11-40
M/Nm
14
12
10
8
M
eff
6
4
2
500
0
n
Fig. 11-21 S1 curve for the 1FT6082-8AF7
The calculated effective motor torque at n
The motor is therefore suitable.
The inverter is selected according to the maximum motor current and
the mean motor current.
♦ Maximum motor current (the saturation influence here can be
ignored)
M
Mot max
≈
I
Mot max
k
Tn 100
♦ Mean motor current, obtained from the magnitude of the torque
characteristic
∑
≈
I
Mot mean
k
⋅ + ⋅ +
16 58 0 6 1147 0 3 6 37 0 6 4 08 0 6 8 39 0 3 12 7 0 6 . . . .
♦ A 6SE7021-0TP50 Compact PLUS inverter is necessary with
I =10.2 A. Since the acceleration and deceleration times are
Un
> 0.25 s, only 1.6 times the rated current can be utilized. Thus
= 14
< 16
I A
Mot max
= 3 6 .
I A
Mot mean
1000
1500
mean
mean
16 57 .
= =
14 A
118 .
⋅ ∆
M t
Mot i i
⋅
T
Tn 100
⋅ + ⋅ +
. . . .
⋅
118 7 .
. ⋅ =
I 16 A
Un
= 10 2 .
< I A
Un
6SE7087-6QX70 (Version AE)
Compendium Motion Control
06.2005
2000 2500
is below the S1 curve.
⋅ + ⋅
. . . .
=
3 6 . A
Siemens AG
SIMOVERT MASTERDRIVES
3000
n/min
-1