Toshiba VF-AS1 Welding System User Manual


 
E6581301
F-28
6
Frequency
Drooping gain
Drooping insensitive torque
Internal torque
command
Drooping gain
H
H
H
H
H
H
Drooping insensitive frequency
Gain2Gain1
[Parameter setting]
Title Function Adjustment range Default setting
H Drooping gain [Note] ~ % 
H Speed at drooping gain 0% ~ Hz 
H Speed at drooping gain H ~ Hz 
H Drooping insensitive torque ~ % 
H Drooping output filter ~ rad/s 
Note: Drooping gain can be changed within a range of 0.1 to 100.0% during operation. When changing the setting
to 0.0 (no drooping) or 0.0, stop operation.
• Drooping control can be performed only when RV is set to , , or .
• When torque over the insensitive torque is applied, the frequency is decreased (during power running) or
increased (during regenerative braking).
• The drooping function is operative at frequencies over the frequency set with H.
• In the frequency range between the frequencies set with H and H, the degree of drooping changes
according to the magnitude of frequency.
• The error in drooping insensitive torque increases in the frequency range above the base frequency, and it is
therefore recommended that these functions be used at frequencies below the base frequency.
• During drooping control, the output frequency is not restricted by the maximum frequency (HJ).
The change in frequency at the time of drooping can be calculated, as described below:
a) Gain by internal torque reference (Gain1)
If internal torque reference (%) Ӎ 0
Gain1 = (internal torque reference - dead band H ) / 100
Gain1 needs to be set at 0 or a positive number.
If internal torque reference (%) < 0
Gain1 = (internal torque reference + dead band H ) / 100
Gain1 needs to be set at 0 or a negative number.
b) Gain by frequency after acceleration (Gain2)
If H < H
| Frequency after acceleration |
Frequency 1 set with H
Gain2 = 0
| Frequency after acceleration | > Frequency 2 set with H
Gain2 = Drooping gain H / 100
If frequency 1 H < | Frequency after acceleration |
Frequency 2 H
If H Ӎ H
| Frequency after acceleration |
Frequency 1 set with H
Gain2 = 0
If | Frequency after acceleration | > Frequency 1 H
Gain2 = Drooping gain H / 100
c) Drooping speed
Drooping speed = base frequency XN
Note
× Gain1 × Gain2
Note: If the base frequency exceeds 100 Hz, count it as 100 Hz.
Gain2 = ×
(| Frequency after acceleration | – Frequency 1
H
)
(Frequency 2
H
– Frequency 1
H
)
Drooping gain
H
100