Toshiba VF-A7 instruction manual To set the V/F characteristic arbitrarily, point setting

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)

Base frequency voltage #1

Output voltage [V]















０

V/f 5-point setting

VF5

VF4

VF3

VF1

VF2

Output frequency

      [Hz]

Note) Set the manual torque boost () from 0 to 3%. Boosting the torque too much may impair the linearity between points.

E-20