E6581090

1) Constant torque characteristic

Setting of V/F control mode selection RV to  (V/F constant)

This setting is applied to loads, such as conveyers and cranes that require the same torque as the rated torque even at low speeds.

 

 

 

Rated voltage of

 

 

 

 

 

 

 

 

 

motor

 

 

 

 

 

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

Output voltage [%]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

XD

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

Output frequency (Hz)

 

 

 

 

 

 

 

 

 

 

Base frequency

XN

5

 

To further increase the torque, increase the setting of the torque boost parameter (XD).

 

Parameter setting

 

 

 

 

 

 

 

 

Title

Function

 

Adjustment range

 

Default setting

 

 

XD

Torque boost 1 (%)

 

0.030.0(%)

 

Depends on the model.

The default torque characteristic is set based on the torque characteristic of World Energy series 4P motors manufactured by Toshiba Industrial Machinery.

When using the inverter with a VF motor or a motor with 6 or more poles, set the torque boost parameter at 80% or so of the default setting.

When the inverter is used with a special motor with a particular V/F ratio, it requires adjustments.

Excessively boosting torque could results in an overcurrent trip. To avoid this, do not increase torque by more than 1.2 times the default torque.

2) Correcting the error in rotational speed due to the slippage of the motor

Setting of V/F control mode selection RV to  (Vector control)

Setting this parameter to 3 causes the inverter to monitor the load currents and automatically correct the error in speed caused by the slippage of the motor. Slip correction gain is adjusted to

correct the error in speed caused by the slippage of the motor.

See 6.12 for details.

Torque

 

Rotational speed converted

 

to frequency

 

Rated torque

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Synchronous

Rotational

 

 

rotational speed

speed

E-8

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Toshiba VF-nC1 instruction manual Xd