6 thermal utilisation, 11 drive dimensioning – Lenze DSD User Manual
Page 318
11
Drive Dimensioning
11.2
Motor selection
318
Lenze · Drive Solution Designer · Manual · DMS 4.2 EN · 12/2013 · TD23
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11.2.6
Thermal utilisation
For the calculation of the thermal utilisation, the heating in the motor is simulated by a PT1 func-
tion.
Important quantities for the utilisation A
th
(t):
• Utilisation of the gearbox via a cycle.
• The utilisation results from the ratio of the instantaneous torque value M(n(t)) and the cor-
responding value M
S1
(n(t)) from the continuous characteristic
• Thermal time constant of the motor.
[11-4] Calculation of the thermal utilisation of the motor via a cycle
[11-5] Diagram of motor: Thermal utilisation
A
th
t
( )
M n t
( )
(
)
M
S1
n t
( )
(
)
--------------------------
2
=
Description
Instantaneous utilisation
100 % utilisation
• If this limit is exceeded, the motor will be overheated.
Max. value of the thermal utilisation
Thermal utilisation
• Simulated value, calculated with the time constant of the motor.
Performance features
• The performance features can also be found in the selection table.