Siemens SINAMICS G110D, Operating Instructions Manual

Page: 118 / 224

Functions
6.7 Motor control
SINAMICS G110D
118
Operating Instructions, 07/2016, FW V3.63, A5E36768472B AB
6.7 Motor control
6.7.1 V/f control with linear characteristics
Table 6- 29 Setting the control type
Parameter Description
P0003 = 2
Extended access
P1300 = 0 Control type: V/f control with linear characteristic
Optimizing the starting characteristics for a high break loose torque and brief overload
The inverter can provide a higher voltage in the lower speed range and when accelerating.
Examples of applications where this is necessary, include:
● Utilizing the brief overload capability of the motor when accelerating
● Driven machines with a high breakaway torque
● Holding a load
Background information: The linear characteristic of the V/f control assumes an ideal motor
without resistive losses. The resistive losses in the motor stator resistance and in the motor
cable reduce the available torque and must not be neglected in all applications. These
losses play a more significant role the smaller the motor and the lower the motor speed. The
losses can be compensated by the V/f control by increasing the voltage at low speeds. (so-
called 'boost parameters': P1310 and P1311)
Note
Only increase the voltage boost in small steps until satisfactory motor behavior is reached.
Excessively high values in P1310 and P1311 can cause the motor to overhead and switch
off (trip) the inverter due to overcurrent .