SEW-Eurodrive MOVIMOT flexible MMF3 C/DBC Series, Руководство по эксплуатации

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10
Project planning
Drive selection
Operating Instructions – MOVIMOT
®
flexible
337
10.4 Drive selection
For drive selection, in addition to the travel diagram that describes the exact travel
cycle, a large number of additional specifications must be made about the operating
and ambient conditions.
It is first necessary to have data for the machine to be driven such as mass, setting
range, speed, information about the mechanical design and so on in order to select
the drive correctly. The appropriate drive can be determined with the calculated
torques and speeds of the drive while taking other mechanical requirements such as
environmental and operating conditions into account.
For selecting the drive, a decision is to be taken if an asynchronous motor or a syn-
chronous motor is to be used. The extensive product range of
SEW‑EURODRIVE is
available for this purpose.
10.5 Recommendations for motor and inverter selection
The basis for motor selection are the limit characteristic curves of the motors in in-
verter operation. The limit characteristic curve states the torque characteristic of the
motor depending on the speed.
The dynamic and thermal limits must be observed when selecting the motor.
10.5.1 Thermal limit characteristic curve
The mean motor speed and the effective torque are calculated during drive selection
to determine the thermal utilization of the motor. The operating point of the motor must
lie below the thermal limit characteristic curve of the motor; otherwise the motor will be
thermally overloaded.
10.5.2 Dynamic limit characteristic curve
The dynamic limit characteristic curve depicts the maximum torque the motor can gen-
erate at a certain speed. Note that the inverter must supply sufficient current for the
motor to reach its maximum torque.
The base speed is especially important for configuration. The base speed is the avail-
able speed up to the maximum motor torque. In inverter operation, the base speed in-
dicates the beginning of field weakening. The motor torque is limited by the voltage
limit characteristic curve in the field-weakening range, and decreases with increasing
speed.
M
N
is determined by the motor. M
max
and n
base
depend on the motor/inverter combina-
tion. For the values for M
max
and n
base
in control modes VFC
PLUS
, CFC, and ELSM
®
,
refer to the motor selection tables in chapter "Motor/inverter assignment".
29128668/EN – 12/2019