Toshiba VF-A7 Welding System User Manual


 
E-20
6) To increase starting torque and the accuracy while saving energy
[Set the motor control mode selection parameter  at
(Sensor-less vector control + automatic energy-saving).]
In vector control mode, the VF-A7 inverter enables the Toshiba standard motor
combined with it to produce large torque even at extremely low speeds. In addition, the output
current is optimally adjusted for energy saving according to the load applied.
This function is effective in:
(1) Obtaining large torque,
(2) Achieving smooth and stable operation even in low speed ranges
(3) Eliminating load fluctuations due to slippage of the motor, and
(4) Making the motor produce large starting torque.
This control mode involves the setting of the motor constant.
Basically, however, there is no need to set the motor constant if the inverter is used for a
Toshiba 4P motor with the same capacity as the inverter.
The motor constant can be set in any of the following three ways:
1)Set the basic parameter  at . In this mode, you can make the setting of both the
automatic energy-saving and the motor constant (auto-tuning) at a time.
=> Refer to 5.2.3) for details.
2)Set the extended parameter  at . In this mode, the motor constant is set
automatically. (Auto-tuning) => Refer to selection 2 in 6.20 for details.
3)The constants of motors can also be set individually.
=> Refer to selection 3 in 6.20 for details.
7) To set the V/F characteristic arbitrarily
[Set the V/f control selection parameter  at (V/f 5-points setting).]
In this mode, the base frequency and the base-frequency voltage for the V/f control need to
be set to operate the motor while switching a maximum of 5 different V/f characteristics.
[Parameter setting]
Title Function Adjustment range Default setting

V/f 5-point setting V/F1 frequency
  [Hz]

V/f 5-point setting V/F1 voltage
  [%]


V/f 5-point setting V/F2 frequency
  [Hz]

V/f 5-point setting V/F2 voltage
  [%]


V/f 5-point setting V/F3 frequency
  [Hz]

V/f 5-point setting V/F3 voltage
  [%]


V/f 5-point setting V/F4 frequency
  [Hz]

V/f 5-point setting V/F4 voltage
  [%]


V/f 5-point setting V/F5 frequency
  [Hz]

V/f 5-point setting V/F5 voltage
  [%]

100% adjustment value (200V class: 200V,400V class: 400V)
Note) Set the manual torque boost () from 0 to 3%. Boosting the torque too much may impair the
linearity between points.
Output frequency
[Hz]












Base frequency voltage #1 
VF1
VF2
VF3
VF4
VF5
V/f 5-point setting
Output voltage [V]