Siemens SIMODRIVE 611 Configuration Manual page 20

Electrical Data
1.1 Definitions
Voltage constant k (value for an average winding temperature rise of 20 K)
E
Value of the induced motor voltage at a speed of 1000 RPM at an ambient temperature of
20 °C.
The phase-to-phase rms motor terminal voltage is specified for FK☐/1FT6.
Winding resistance R
The resistance of a phase at a room temperature of 20 °C is specified.The winding has a
star circuit configuration.
Inductance L
D
The rotating field inductance is specified.
Electrical time constant T
Quotient obtained from the rotating field inductance and winding resistance. T
Thermal time constant T
Defines the increase in the motor frame temperature when the motor load is suddenly
increased (step function) to the permissible S1 torque. The motor has reached 63% of its
final temperature after T
Mechanical time constant T
The mechanical time constant is obtained from the tangent at a theoretical ramp-up function
through the origin.
T
mech
J
mot
R
ph
k
T
Moment of inertia J
The moment of inertia of the motor is described in the motor sections.
Shaft torsional stiffness C
This specifies the shaft torsional stiffness from the center of the rotor core to the center of
the shaft end.
Brake resistor R
opt
R
opt
with the motor winding for armature short-circuit braking.
1-10
ph
el
th
.
th
mech
= 3 ∙ R ∙ J /k [s]
T 2
ph mot
= Servomotor moment of inertia [kgm
= Phase resistance of the stator winding [Ohm]
= Torque constant [Nm/A]
T
corresponds to the optimum resistance value per phase, externally switched in series
]
2
Configuration Manual, (PJAL), 11.2005 Edition, 6SN1 197-0AD07-0BP4
= L
el D
General Section for Synchronous Motors
/R
ph