Hitachi SJ Series User Manual page 220

Chapter 12
12.9.2 Drive with V/f control (constant
torque characteristics)
Ｑ
• To use with a load for running conveyors and
bogies.
• To use in a fan/pump that changes its output
frequently.
• To avoid trips that may be likely to happen when
driven with reducing torque characteristics.
• To run multiple motors with a single inverter.
Ａ
V/f control (constant torque characteristics)
• With constant torque characteristics, the output
voltage is outputted proportionally to a given
command frequency along the straight line drawn
from the point 0 Hz/0 V to the intersection of the
base frequency and the rated voltage.
• The output voltage corresponding to a frequency
range from 0 Hz to the base frequency is
determined proportionally to the given frequency,
but the output voltage corresponding to a
frequency range from the base frequency to the
maximum frequency is constant irrespective of the
frequency.
• Use of the manual boost function renders the
output voltage higher than that on the basic
proportional line by the boost voltage.
The manual boost function is effective in the case
of low speeds and insufficient torque.
Parameter
Item Parameter
Control mode [AA121]
Stability constant [HA110]
Base frequency [Hb104]
Maximum
[Hb105]
frequency
Motor's rated
[Hb106]
voltage
！
• When a motor is hunting and vibrating, an
• When a single inverter runs multiple motors and
Rated
voltage
Data
00
0~1000(%)
10.00 to the maximum
frequency (Hz)
Base frequency to 590.00
(Hz)
1~1000 (V)
12-9-3
adjustment of the stability constant [HA110] may
improve the state of the motor.
the motors are vibrating, a downward adjustment of
the stability constant [HA110] may stabilize the
state of the motors.
Output voltage (V)
0
Base frequency
Description
To be used with the V/f control and the
constant torque characteristics (IM).
To adjust the control for reducing the
hunting of motors.
To set the base frequency of motors.
To set the maximum frequency of motors.
Set the rated voltage of motors.
Inverter Function
Command
frequency (Hz)
Maximum
frequency