Toshiba TOSVERT VF-MB1 Instruction Manual page 168

6.15.6 Output voltage adjustment/Supply voltage correction
vlv : Base frequency voltage 1
f307 : Supply voltage correction (output voltage limitation)
 Function
Supply voltage correction: Maintains a constant V/F ratio, even when the input voltage fluctuates.
Output voltage limitation: Limits the voltage at frequencies exceeding the base frequency. Applied when
[Parameter setting]
6
vlv
f307
*1: Default setting values vary depending on the setup menu setting. Refer to section 11.5.
If f307 is set to " 0 " or " 2 ", the output voltage will change in proportion to the input voltage.
Even if the base frequency voltage ( vlv parameter ) is set above the input voltage, the output voltage
will not exceed the input voltage.
The rate of voltage to frequency can be adjusted according to the rated motor capacity. For example,
setting f307 to " 0 " or " 1 " prevents the output voltage from increasing, even if the input voltage
changes when operation frequency exceeds the base frequency.
When the V/F control mode selection parameter (  ) is set to any number between 2 to 6 , the supply
voltage is corrected regardless of the setting of f307 .
Base frequency voltage1
The  parameter adjusts the voltage corresponding to the base frequency 1 vl so that no
voltage exceeding the vlv set value is put out. (This function is enabled only when f307 is set
to either " 0 " or " 1 ".)
Supply voltage correction
The  parameter maintains a constant V/F ratio, even when the input voltage decreases. The
torque during low-speed operation is prevented from decreasing.
operating a special motor with low induced voltage.
Title Function
Base frequency voltage1
Supply voltage correction
(output voltage limitation)
Adjustment range
50-330 (240V class)
50-660 (500V class)
0: Supply voltage uncorrected,
output voltage limited
1: Supply voltage corrected,
output voltage limited
2: Supply voltage uncorrected,
output voltage unlimited
3: Supply voltage corrected,
output voltage unlimited
F-48
E6581697
Default setting
*1
*1