4)To increase starting torque and the accuracy of operation - Vector control

[Set the V/f control selection parameter  at (Sensorless vector control).]

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. The vector control mode 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

(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 . With this parameter, you can make the setting of both the sensorless vector control and the motor constant (auto-tuning) at a time.

=> Refer to 5.2.2) 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. [Procedure for setting the V/f control selection parameter  at (Sensorless vector control)]

key operated,

LED display

Operation

 

 

The running frequency is displayed. (Make this setting when the

 



motor is out of operation.)(If the monitor display selection

 

 

parameter  is set at [Running frequency])

MON



Press the MON key to call up the first basic parameter

(Automatic acceleration/deceleration).

 

 



Switch to the parameter (Motor control mode selection)

by pressing key.

 

 

ENT

Press the Enter key to display the parameter setting (set

value). (Default setting: (Constant torque))

 

 

Change the parameter setting to (Sensorless vector

control) by pressing the key.

 

 

ENT



Press the Enter key to save the change. Then,  and the

set value  are displayed alternately.

 

 

5) To increase the starting torque while saving energy

[Set the motor control mode selection parameter  at  (Automatic torque boost + automatic energy-saving).]

In this mode, the load current is monitored in all speed ranges and the inverter's output voltage (torque boost) is adjusted automatically so that the motor can always produce torque large enough for stable operation. In addition, the output current is optimally adjusted for energy saving according to the load applied.

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 two ways:

1)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.

2)The constants of motors can also be set individually.

 

 

 

 

 

 

 

=>

Refer

to

selection

3

in

6.20

for

details.

E-19

Page 80
Image 80
Toshiba VF-A7 Value. Default setting Constant torque, Change the parameter setting to Sensorless vector