Motor control types
The inverter provides various motor control types.
Linear V/f characterisc control
The output voltage is increased proporonately to the output frequency.
In case of low output frequencies, the motor voltage can be increased to ensure a minimum
current for the breakaway torque. In the eld weakening range, the output voltage of the
inverter is constant (mains voltage) and the frequency can be further increased depending on
the load. The maximum torque of the motor is reduced squarely to the frequency increase.
the maximum output power of the motor being constant.
Applicaon areas are for instance: Single drives with constant load.
P Power M
rated
Rated torque
V Voltage f
rated
Rated frequency
M Torque M
rated
Rated torque
f Frequency f
rated
Rated frequency
Square-law V/f characterisc control
The output voltage is increased squarely to the output frequency.
In case of low output frequencies, the motor voltage can be increased to ensure a minimum
current for the breakaway torque. In the eld weakening range, the output voltage of the
inverter is constant (mains voltage) and the frequency can be further increased depending on
the load. The maximum torque of the motor is reduced squarely to the frequency increase.
the maximum output power of the motor being constant.
Applicaon areas are for instance:
•
Pumps
•
Fans
•
Fan
Appendix
Good to know
Motor control types
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