Hitachi SJ Series, User Manual

Page: 220 / 786

12-9-3
Chapter 12 Inverter Function
12.9.2 Drive with V/f control (constant
torque characteristics)
• 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.
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
• When a motor is hunting and vibrating, an
adjustment of the stability constant [HA110] may
improve the state of the motor.
• When a single inverter runs multiple motors and
the motors are vibrating, a downward adjustment of
the stability constant [HA110] may stabilize the
state of the motors.
Item Parameter Data Description
Control mode [AA121] 00
To be used with the V/f control and the
constant torque characteristics (IM).
Stability constant [HA110] 0~1000(%)
To adjust the control for reducing the
hunting of motors.
Base frequency [Hb104]
10.00 to the maximum
frequency (Hz)
To set the base frequency of motors.
Maximum
frequency
[Hb105]
Base frequency to 590.00
(Hz)
To set the maximum frequency of motors.
Motor's rated
voltage
[Hb106] 1~1000 (V) Set the rated voltage of motors.
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Command
frequency (Hz)
Output voltage (V)
Base frequency
Maximum
frequency
0
Rated
voltage