Toshiba VF-A7 Welding System User Manual


 
F-20
6.12 PWM carrier frequency
 PWM carrier frequency
[Parameter setting]
Title Function Adjustment range Default setting

PWM carrier frequency
 
(

,

) [kHz](*1)
[Upper limits differ by applicable motor
capacity. Refer to the table below.]
Model
dependent
(*1)Setting the PWM carrier frequency larger than the default value, reduction of rated current is
needed. For details, refer to figure and table below.
PWM carrier freq. [kHz]
Volta
g
e
class [V]
A
pplicable moto
r
capacity [kW]
Default settin
g
Upper limit
Rated current
at upper limit [%]
Max value, no rated current
reduction is needed [kHz]
0.4 2.2
5.5 11 18.5
12 15 No need of rated current reduction
3.7 12 15 90 12
15 12 15 95 12
22 12 15 90 12
30 12 15 93 12
37 8 15 No need of rated current reduction
45 8 15 80 8
55 2.2 8 85 3
200
75 90 2.2 5 No need of rated current reduction
0.75 2.2,
5.5 11, 18.5
12 15 No need of rated current reduction
3.7 15 22 12 15 90 12
30 12 15 89 12
37 8 15 No need of rated current reduction
45 8 15 80 11
55 8 15 65 8
75 2.2 8 70 4
90/110 220 2.2 5 80 2.2
400
280 2.2 5 75 2.2
Note1) In vector control mode, set the carrier frequency to 2.2 [kHz] or over. Operation may
become unstable if the carrier frequency is lower than 2.2 [kHz].
Note2) In the case that the operation frequency is more than 130Hz,carrier frequency is limited
to less than 10kHz automatically.
Note3) Set the carrier frequency to 2.2kHz when sine wave filter (LFL,LFC)is used at output
side of inverter. Filter can be damaged by fire in the case of other than 2.2kHz.
6.13 Trip-less enhancement
6.13.1 Auto-restart (restart during free-run (coast))
 Auto-restart  Auto-restart mode
 Auto-restart adjustment #1  Auto-restart adjustment #3
 Auto-restart adjustment #2
Warning
Mandatory
Do not get near the motor or the machine.
The motor and the machine unexpectedly restart after recovery from a momentary power
failure, which might cause injury to persons.
Stick caution labels to the inverter, the motor and the machine, to prevent accidents due
to an unexpected restart of them after recovery from a momentary power failure.
Function
1) The sound tone of acoustic noise can be changed by adjusting the PWM carrier frequency. This
adjustment is effective in preventing the motor from resonating with its load(machine) or its fan cover.
2) Decreasing the carrier frequency is also effective in reducing electromagnetic.
Note
)
Decreasin
g
the carrier fre
q
uenc
y
reduces electroma
g
netic noise but increases acoustic noise.
PWM carrier fre
q
uenc
y
[
kHz
]
Rated current [%]
100
Default setting Upper limit