Hitachi WJ200-001S Instruction Manual page 45

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Velocity Profiles
The WJ200 inverter is capable of sophisticated
speed control. A graphical representation of that
capability
configure
manual makes use of the velocity profile graph
used in industry (shown at right). In the
example,
deceleration
and
Acceleration and deceleration settings specify
the time required to go from a stop to maximum
frequency (or vise versa). The resulting slope
(speed change
acceleration or deceleration. An increase in
output frequency uses the acceleration slope,
while a decrease uses the deceleration slope.
The accel or decel time a particular speed
change depends on the starting and ending
frequencies.
However, the slope is constant, corresponding to the full-scale accel or decel time
setting. For example, the full-scale acceleration setting (time) may be 10 seconds – the
time required to go from 0 to 60Hz.
The WJ200 inverter can store up to 16 preset
speeds. And, it can apply separate acceleration
and deceleration transitions from any preset to
any other preset speed. A multi-speed profile
(shown at right) uses two or more preset speeds,
which you can select via intelligent input
terminals. This external control can apply any
preset speed at any time.
Alternatively, the selected speed is infinitely variable across the speed range. You can
use the potentiometer control on the keypad for manual control. The drive accepts
analog 0-10VDC signals and 4-20 mA control signals as well.
The inverter can drive the motor in either
direction. Separate FW and RV commands
select the direction of rotation. The motion
profile example
followed by a reverse motion of shorter duration.
The speed presets and analog signals control
the magnitude of the speed, while the FWD and
REV commands determine the direction before
the motion starts.
NOTE: The WJ200 can move loads in both directions. However, it is not designed for NOTE
NOTE NOTE
use in servo-type applications that use a bipolar velocity signal that determines
direction.
will help you understand
the associated parameters. This
acceleration
is a ramp to a set speed,
is a decline to a stop.
divided by
shows a
Speed
and
Speed
time) is the
Speed
Speed
forward motion
Set speed
Accel Decel
0
Velocity Profile
Maximum speed
0
Acceleration
(time setting)
Speed 2
Speed 1
0
Multi-speed Profile
Forward move
0
Reverse move
Bi-directional Profile
t
t
t
t