Mitsubishi Electric F700 User Manual

94
Setting of acceleration/deceleration time
and acceleration/deceleration pattern
4.7.3 Acceleration/deceleration pattern (Pr.29, Pr.140 to Pr.143)
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 156)
You can set the acceleration/deceleration pattern suitable for application.
You can also set the backlash measures that stop acceleration/deceleration once at the parameter-set
frequency and time during acceleration/deceleration.
Parameter
Number
Name
Initial
Value
Setting
Range
Description
29
Acceleration/deceleration pattern
selection
0
0 Linear acceleration/ deceleration
1 S-pattern acceleration/deceleration A
2 S-pattern acceleration/deceleration B
3 Backlash measures
140 Backlash acceleration stopping frequency 1Hz 0 to 400Hz
Set the stopping frequency and time
for backlash measures.
Valid when Pr. 29 = 3
141 Backlash acceleration stopping time 0.5s 0 to 360s
142 Backlash deceleration stopping frequency 1Hz 0 to 400Hz
143 Backlash deceleration stopping time 0.5s 0 to 360s
(1) Linear acceleration/ deceleration ( Pr. 29 = "0", initial value)
⋅ When the frequency is changed for acceleration, deceleration, etc. in inverter
operation, the output frequency is changed linearly (linear acceleration/
deceleration) to reach the set frequency without straining the motor and
inverter. Linear acceleration/deceleration has a uniform frequency/time
slope.
(2) S-pattern acceleration/deceleration A ( Pr. 29 = "1")
⋅ For machine tool spindle applications, etc.
Used when acceleration/deceleration must be made in a short time to a high-
speed range of not lower than the base frequency. In this acceleration/
deceleration pattern, Pr. 3 Base frequency (fb) is the inflection point of the S
pattern and you can set the acceleration/deceleration time appropriate for
motor torque reduction in a constant-power operation region of base
frequency or higher.
CAUTION
⋅ As the acceleration/deceleration time of S-pattern acceleration/deceleration A, set the time taken until Pr. 3 Base frequency is
reached, not Pr. 20 Acceleration/deceleration reference frequency.
(3) S-pattern acceleration/deceleration B ( Pr. 29 = "2")
⋅ For prevention of load shifting in conveyor and other applications. Since
acceleration/deceleration is always made in an S shape from current
frequency (f2) to target frequency (f1), this function eases shock produced at
acceleration/deceleration and is effective for load collapse prevention, etc.
(4) Backlash measures ( Pr. 29 = "3", Pr. 140 to Pr. 143)
⋅ What is backlash?
Reduction gears have an engagement gap and have a dead zone between
forward rotation and reverse rotation. This dead zone is called backlash, and this
gap disables a mechanical system from following motor rotation.
More specifically, a motor shaft develops excessive torque when the direction of
rotation changes or when constant-speed operation shifts to deceleration, resulting
in a sudden motor current increase or regenerative status.
⋅ To avoid backlash, acceleration/deceleration is temporarily stopped.
Set the acceleration/deceleration stopping frequency and time in Pr. 140 to Pr. 143.
CAUTION
Setting the backlash measures increases the acceleration/deceleration time by the stopping time.
♦ Parameters referred to ♦
Pr. 3 Base frequency Refer to page 80
Pr. 7 Acceleration time, Pr. 8 Deceleration time, Pr. 20 Acceleration/deceleration reference frequency Refer to page 91
Setting value "0"
[Linear acceleration
/ deceleration]
Output frequency (Hz)
Time
fb
Output frequency (Hz)
Setting value "1"
Time
[S-pattern acceleration
/deceleration A]
f1
Setting value "2"
[S-pattern acceleration
/deceleration B]
f2
Time
Set frequency (Hz)
Output frequency (Hz)
Pr. 142
Pr. 143
Pr. 141
Pr. 140
P
r. 13
Output frequency (H
z
[Anti-backlash measure
function]
Setting value "3"
Time

Mitsubishi Electric F700 Specifications

General

Brand	Mitsubishi Electric
Model	F700
Category	Inverter
Language	English