Toshiba VF-FS1 instruction manual E6581381

Models: VF-FS1

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E6581381

+The droop control function refers to the function of operating the power-running motor at operating frequency f1 (Hz) that is lower than command frequency f0 (Hz) by droop frequency ∆f (Hz) when the torque current is T1 (%). (See the above figure.)

The droop frequency ∆f can be calculated, using the following expression.

Droop frequency ∆f (Hz)=base frequency XN × H× (Torque current T1 - H)

When the torque current is above the specified droop insensitive torque band (H), the frequency is reduced during power running or increased during regenerative braking. The above figure shows an example of the operating frequency during power running. During regenerative braking, control is performed in such a way as to increase the frequency.

The droop function is activated above the torque current set with H.

The amount of droop frequency ∆f varies depending on the amount of torque current T1.

Note: If the base frequency XN exceeds 100Hz, count it as 100Hz.

Control is exercised between the starting frequency (H) and the maximum frequency (HJ).

[An example of calculation]

Parameter setting:Base frequency XN=60 (Hz), droop gain H=10 (%) Droop insensitive torque band H=30 (%)

6 Droop frequency ∆f (Hz) and operating frequency f1 when command frequency f0 is 50 (Hz) and torque current T1 is 100 (%) are as follows.

Droop frequency ∆f (Hz)=XN × H × (T1 - H)

=60 (Hz) × 10 (%) × (100 (%) - 30 (%)) =4.2 (Hz)

Operation frequency f1 (Hz) = f0 - ∆f = 50 (Hz) - 4.2 (Hz)=45.8 (Hz)

F-40

Page 136
Image 136
Toshiba VF-FS1 instruction manual E6581381