Linear V/f characteristic
The linear V/f characteristic leads to a constant torque.
Details
Select V/f characteristic control with linear characteristic:
1.
Motor control mode 0x2C00 (P300.00) = "V/f characteristic control (VFC open loop) [6]"
2.
V/f characteristic shape 0x2B00 (P302.00) = "Linear [0]"
Setting of the V/f characteristic:
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Limiting factors for the V/f characteristic are the rated mains voltage 0x2540:001 (P208.01), the minimum frequency 0x2915 (P210.00) and the maximum frequency 0x2916 (P211.00).
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The base voltage 0x2B01:001 (P303.01) is usually set to the rated motor voltage (motor nameplate data). The base voltage is preset to the rated mains voltage. This in turn is preset according to the product key of the inverter. 
Mains voltage
Mains voltage –
The base frequency 0x2B01:002 (P303.02) is usually set to the rated motor frequency (motor nameplate data).
The actual output frequency can exceed the set maximum frequency if the gain for the slip compensation in 0x2B09:001 (P315.01) is set to a value higher than 0.
Example
Mot power
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400 V/50 Hz
Settings
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Maximum frequency 75 Hz
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Minimum frequency 10 Hz
Explanation
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Graphic on the left: The inverter is operated with a rated mains voltage of 400 V.
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Graphic on the right: The inverter is operated with a rated mains voltage of 480 V. This allows the output voltage to further increase above 50 Hz.
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Parameter
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Designation
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Setting for this example
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Rated mains voltage
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400 Veff [1] (on the left) / 480 Veff [2] (on the right)
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Minimum frequency
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10 Hz
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Maximum frequency
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75 Hz
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Base voltage
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400 V
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Base frequency
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50 Hz
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