Fuzzy Most Suitable Acceleration And Deceleration - Hitachi J300 Series Instruction Manual

3.

Fuzzy most suitable acceleration and deceleration

[Outline of the function]
The fuzzy most suitable acceleration and deceleration function realizes acceleration and decelera-
tion characteristics using the inverter capability at its maximum under fuzzy control to eliminate
troublesome setting of the acceleration and deceleration time.
The acceleration time is a time for acceleration at the current specified by the overload restriction
constant.
The deceleration time is a time for decelerating so that the current does not exceed 150% of the
specified one or the DC voltage in the inverter circuit does not exceed 385V. (770 V for the
400V class.)
The function sets the acceleration and deceleration time automatically in response to a change in
the load or inertia in real time.
[Precautions]
1. This function is not suitable for a machine which requires a constant acceleration and decel-
eration time. The acceleration and deceleration time varies with the magnitude of the load or
inertia.
2. When the inertia of the machine is more than about 20 times of that of the motor shaft, a trip
may occur.
3. The acceleration and deceleration time of the same motor always varies with a change of the
current.
4. The fuzzy most suitable acceleration and deceleration setting function is valid only under the
V/F control. In the high start torque running mode (under the sensorless vector control), the
normal running is performed.
5. If the jogging running is executed when the fuzzy most suitable acceleration and decelera-
tion setting function is selected, the jogging operation cannot be performed due to the fuzzy
control.
6. When the load is more than the rated one, the deceleration time may be increased.
7. When acceleration and deceleration (the cycle is 2 [s] or less) are repeated frequently, a trip
may occur.
8. If an external braking unit is used, the motor cannot stop within the deceleration time set
with a braking resistor. In such a case, do not use the fuzzy acceleration/deceleration func-
tion.
CTi Automation - Phone: 800.894.0412 - Fax: 208.368.0415 - Web: www.ctiautomation.net - Email: info@ctiautomation.net
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