Mitsubishi Electric FR-A740-00023 Instruction Manual page 184

Setting of acceleration/deceleration time
and acceleration/deceleration pattern
(2) Optimum acceleration/deceleration mode (Pr. 292 = "3")
⋅ The optimum operation within the rating range where the inverter can be continuously used regardless of the
inverter capability is performed.
Automatically set torque boost and acceleration/deceleration time so that the average current during acceleration/
deceleration is the rated current by the self-learning of the inverter.
It is appropriate for applications such as automatic transfer machine, etc. which is small in load change and is
operated in a predetermined pattern.
⋅ At the initial time when the optimum acceleration/deceleration mode has been selected, operation is performed at the values
set in Pr. 0 Torque boost, Pr. 7 Acceleration time and Pr. 8 Deceleration time. After operation, the average current and peak current
are calculated from the motor current during acceleration/deceleration.These values are compared with the reference current
(initial value is rated inverter current) and calculated, then more appropriate values are set in Pr. 0, Pr. 7 and Pr. 8 .
After that, operation is performed under the conditions of Pr. 0, Pr. 7 and Pr. 8 set, and more appropriate values are calculated.
Note that the Pr. 0 value will not change under advanced magnetic flux vector control, real sensorless vector control or vector
control.
⋅ Storage of parameters
The optimum values of Pr. 0, Pr. 7 and Pr. 8 are written to both the
parameter RAM and EEPROM only three times of acceleration/
deceleration after the optimum acceleration/deceleration mode
has been selected or after the power is switched on or the
inverter is reset. At of after the fourth attempt, they are not
stored into EEPROM. Hence, after power-on or inverter reset,
the values changed at the third time are valid. Note that the
values changed at the fourth or later time are calculated to
optimum and the values of Pr. 0, Pr. 7 and Pr. 8 are set to RAM,
the values can be stored into EEPROM by reading and writting
the values with the operation panel and paramter unit.
⋅ Either acceleration or deceleration can be made in the optimum acceleration/deceleration mode using Pr. 293
Acceleration/deceleration separate selection.
When the setting value is "0" (initial value), both acceleration and deceleration are made in the optimum
acceleration/deceleration mode.
⋅ It is inappropriate for machines which change in load and operation conditions.
Since the stored optimum values are used for the next operation, faults, e.g. acceleration/deceleration is not made
if conditons change, alarm stop is made due to overcurrent protective function, may occur.
REMARKS
⋅ If shortest acceleration/deceleration mode has been selected, inputting the jog signal (jog operation), RT signal (second
function selection) or X9 signal (third function selection) during an inverter stop will switch to the normal operation and give
priority to jog operation, second function selection or third function selection. Note that JOG and RT signal input is invalid even
if JOG signal and RT signal are input during operation in shortest/optimum acceleration/deceleration mode.
⋅ Because of the learning system, this mode is not valid at the first operation after the optimum acceleration/deceleration mode is set.
⋅ The optimum value are operated on only when acceleration is made from a stop to 30Hz or more or when deceleration is made
from 30Hz or more to stop.
⋅ When the motor is not connected or output current is less than 5% of the rated inverter current, optimum acceleration/
deceleration mode will not function.
(3) Adjustment of shortest and optimum acceleration/deceleration mode (Pr. 61 to Pr. 63)
⋅ By setting the adjustment parameters Pr. 61 to Pr. 63, the application range can be made wider.
Parameter
Name
Number
Reference
61
current
Reference value
62
at acceleration
Reference value
63
at deceleration
REMARKS
⋅ Pr. 61 to Pr. 63 are invalid when real sensorless vector control or vector control is selected in the shortest acceleration/
deceleration mode.
⋅ Since the Pr. 61 to Pr. 63 settings automatically return to the initial value (9999) if the Pr. 292 setting is changed, set Pr. 292 first
when you need to set Pr. 61 to Pr. 63.
♦ Parameters referred to ♦
Pr. 0 Torque boost Refer to page 138
Pr. 7 Acceleration time, Pr. 8 Deceleration time
Pr. 22 Stall prevention operation level
Pr. 22 Torque limit level Refer to page 94
174
Setting Range
01800 or For example, when the motor and inverter are different in capacity, set
0 to 500A
the rated motor current value.
less
Shortest acceleration/deceleration: Set reference current (A) of the stall
prevention operation level during acceleration/deceleration
02160 or
0 to 3600A
Optimum acceleration/deceleration: Set reference current (A) of the
more
optimum current during acceleration/deceleration
9999 (initial value) The rated inverter current is defined as reference.
Set when it is desired to change the reference level of acceleration and
deceleration.
Shortest acceleration/deceleration: Set the stall prevention operation level
0 to 220%
(ratio to the current value of Pr. 61 ) during acceleration/deceleration.
Optimum acceleration/deceleration: Set the optimum current level (ratio to
the current value of Pr. 61 ) during acceleration/deceleration.
Shortest acceleration/deceleration: The 150% value during shortest
9999
acceleration/deceleration is judged as the stall prevention operation level.
(initial value)
Optimum acceleration/deceleration: 100% is the optimum value
Refer to page 167
Refer to page 144
Number of Pr. 0, Pr. 7, Pr. 8
Optimum
EEPROM
Value
value
Changes
1 to 3 times Updated Updated
Unchanged
4 or more
from third Updated
times
value
Description
Optimum
RAM
Conditions
value
Updated
Updated