Optimizing Motor Starting - Siemens Sinamics G110M Operating Instructions Manual

Advanced commissioning
6.17 Motor control
Requirement
Freely adjustable U/f char-
acteristic
U/f characteristic with inde-
pendent voltage setpoint
Additional information on U/f characteristics can be found in the parameter list and in the
function diagrams 6300 ff of the List Manual.
6.17.1.3

Optimizing motor starting

After selection of the U/f characteristic, no further settings are required in most applications.
In the following circumstances, the motor cannot accelerate to its speed setpoint after it has
been switched on:
● Load moment of inertia too high
● Load torque too large
● Ramp-up time p1120 too short
To improve the starting behavior of the motor, a voltage boost can be set for the U/f
characteristic at low speeds.
Setting the voltage boost for U/f control
Requirements
● Set the ramp-up time of the ramp-function generator to a value 1 s (< 1 kW) ... 10 s
(> 10 kW), depending on the power rating of the motor.
● Increase the starting current in steps of ≤ 5%. Excessively high values in p1310 ... p1312
can cause the motor to overheat and switch off (trip) the inverter due to overcurrent.
If message A07409 appears, it is not permissible that you further increase the value of
any of the parameters.
Procedure
Proceed as follows to set the voltage boost:
1. Switch on the motor with a setpoint of a few revolutions per minute.
2. Check whether the motor rotates smoothly.
3. If the motor does not rotate smoothly, or even remains stationary, increase the voltage
boost p1310 until the motor runs smoothly.
4. Accelerate the motor to the maximum speed with maximum load.
5. Check that the motor follows the setpoint.
6. If necessary, increase the voltage boost p1311 until the motor accelerates without
problem.
236
Application Remark
examples
- -
- The interrelationship between the frequency
and voltage is not calculated in the inverter,
but is specified by the user.
Distributed converter for SIMOGEAR geared motors
Operating Instructions, 09/2017, FW V4.7.9, A5E31298649B AH
Characteristic Parameter
Adjustable p1300 = 3
characteristic
Independent p1300 = 19
voltage set-
point