Siemens SIMOTICS-T 1FW68 Engineering Manual page 117

n
MAX
n
MAX,MMAX
n
MAX,INV
n
MAX,0
M
0
I
0
M *
0
I *
0
Physical constants
D
MOT
n
SEGM
F
A
k
T,20
k
E
k
M,20
t
TH
1FW68 radial segment motors
Configuration Manual, 04/2017, 6SN1197-0AE02-0BP1
Maximum speed (maximum permissible operating speed)
Maximum speed at which the stator segment can supply the maximum torque
M .
MAX
Maximum speed at which a Voltage Protection Module VPM is not required.
No-load speed; max. speed without load.
Torque for speed n = 1 rpm at which the load and power loss are still evenly
distributed across all stator segment phases.
Current (rms value) of the stator segment at torque M
Thermal static torque when the current is unevenly distributed across the three
stator segment phases. An uneven current load occurs in the following operating
modes:
• Standstill
• Operation with short cyclic rotations (< 1 pole pitch)
• for n << 1 rpm
Since the saturation effect can be disregarded for the rated current, the following
applies (approximately):
Thermal stall current (rms value) of the stator segment at M
applies:
Air gap diameter:
Number of stator segments when fully equipped.
Force of attraction between a stator segment and the rotor.
Stator segment torque constant at a rotor segment temperature of 20 °C (refers to
the lower linear range of the torque–current characteristic).
Voltage constants for calculating the mutually induced line-to-line voltage.
Motor constant for a winding temperature of T = 20 °C.
The motor constant k (T) can be calculated for other temperatures:
M
k (T) = k ∙ [1 + α(T – 20 °C)]
M M,20
using the temperature coefficients α = −0.001 1/K for magnets
k (T) = k ∙ [1 - 0.001 ∙ (T – 20 °C)]
M M,20
Thermal time constant of the stator segment winding. This is derived from the tem-
perature characteristic in the winding with a sudden load and constant current. See
diagram below. After time t
approx. 63 % of its final temperature T
respond beforehand.
Technical data and characteristics
has elapsed, the stator segment winding reaches
TH
, if the temperature protection does not
GRENZ
6.1 Explanations
and speed n = 1 rpm.
0
. The following
0 *
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