Toshiba Q9 Plus ASD, Installation & Operation Manual

Page: 254 / 434

E6581611
F-74
6
,
The drooping control function is to operate the power-running motor at operating frequency f
1
(Hz), which is
lower than command frequency f
0
(Hz) by droop frequency Δ f (Hz), when the torque current is T
1
(%). (See
the figure above.)
•
The droop frequency Δ f can be calculated using the following expression.
Droop frequency Δ f (Hz)=base frequency vl × f320 × (Torque current T
1
- f323 )
•
When the torque current is above the specified droop insensitive torque band ( f323 ), the frequency is
reduced during power running or increased during regenerative braking. The figure above shows an
example of the operating frequency during power running. During regenerative braking, control is
performed to increase the frequency.
•
The drooping control function is activated above the torque current set with f323 .
•
The amount of droop frequency Δ f varies depending on the amount of torque current T
1
.
Note: If the base frequency
vl exceeds 100Hz, count it as 100Hz.
Control is exercised between the starting frequency ( f240 ) and the maximum frequency ( fh ).
[An example of calculation]
Parameter setting: Base frequency
vl =60 (Hz), droop gain f320 =10 (%)
Droop insensitive torque band f323 =30 (%)
Droop frequency Δ f (Hz) and operating frequency f
1
when command frequency f
0
is 50 (Hz) and torque
current T
1
is 100 (%) are as follows;
Droop frequency Δ f (Hz)= vl × f320 × (T
1
- f323 )
=60 (Hz) × 10 (%) × (100 (%) - 30 (%))
=4.2 (Hz)
Operation frequency f
1
(Hz) = f
0
- Δ f = 50 (Hz) - 4.2 (Hz)=45.8 (Hz)
Power running