Using Motor Acceleration/Deceleration Function; Changing The Acceleration/Deceleration Time - Hitachi WJ Series User Manual

Chapter 9

9.3 Using Motor Acceleration/Deceleration Function

9.3.1

Changing the Acceleration/Deceleration Time

 How to shorten the motor acceleration and make it more responsive?
Q
 How to increase the acceleration time to prevent over current?
 How to increase the deceleration time to prevent overvoltage?
 How to slow down acceleration and deceleration to mitigate the large motor load inertia?
 Appropriately set the motor acceleration/deceleration time. Set them with a longer time for slow
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acceleration/deceleration or a shorter time for fast acceleration/deceleration.
 The acceleration/deceleration time are calculated according to the time it takes for the speed to
rise from 0 Hz to the maximum frequency setting.
 The acceleration/deceleration time can also be changed during operation according to the
commands of the two-stage acceleration/deceleration function. For details, refer to "9.3.2
Switching the Acceleration/Deceleration Time in Two Stages".
 The acceleration/deceleration curve selection ([A097]/[A098]) allows you to start with gradual
acceleration/deceleration. For details, refer to "9.3.4 Changing the Acceleration/Deceleration
Pattern".1
 When the "Acceleration/Deceleration cancellation [LAC] (46)" input terminal turns on, the
acceleration/deceleration time is set to zero seconds. In this case, the output frequency
instantly responds to the changes in the frequency command. For details, refer to "9.3.5 Making
the Frequency Instantaneously Follow the Command".
Acceleration time setting
or monitor [F002]
Deceleration time setting
or monitor [F003]
Program function (EzSQ)
(Reserved variable
<ACCEL>/<DECEL>)
Acceleration time 2 [A092]
Deceleration time 2 [A093]
Acceleration/deceleration
curve selection
[A097]/[A098]
Acceleration/deceleration
curve calculation
(The values in square brackets and the switch positions shown in the figure are the default values.
All input terminal functions not assigned to input terminal function selection [C001] to [C007] are turned off.)
 If the acceleration/deceleration hold function is turned on or off when the acceleration/
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deceleration pattern selection ([A097]/[A098]) is not set to a straight line, the acceleration/
deceleration pattern is recalculated using the frequency command when the hold function is
turned off as the starting point. Acceleration/deceleration is then performed again.
*1. "2nd-motor control [SET]" target parameter. The second control parameter is also subject to setting.
*2. The EzSQ reserved variable <ACCEL>/<DECEL> are enabled when [P031] = "EzSQ (03)".
*1
*1
[00]
*2
03
*1
*1
Acceleration/deceleration
curve selection
[A097]/[A098]
Other than straight line
Straight line
9-3-1
Inverter Functions
OFF
ON
Less than the setting
Equal to or more than
the setting
Forward/reverse switch
Rotation direction
(forward/reverse)
Rotation direction
(reverse/forward)
Acceleration/
0 sec
Deceleration
cancellation
[LAC] (46)
ON
ON
OFF
OFF
Accel/Decel change
trigger selection
*1
[A094]
[00]
01
02
Acceleration/
deceleration time