Mitsubishi Electric FR-D720S SC EC Instruction Manual page 179

Parameter
6.2.2 General-purpose magnetic flux vector control (Pr. 9, Pr. 71, Pr. 80)
Large starting torque and low speed torque are available with general-purpose magnetic flux
vector control.
What is general-purpose magnetic flux vector control?
The low speed torque can be improved by providing voltage compensation to flow a motor cur-
rent which meets the load torque. With setting slip compensation (Pr. 245 to Pr. 247), output fre-
quency compensation (slip compensation) is made so that the actual motor speed goes closer
to a speed command value. Effective when load fluctuates drastically, etc.
General-purpose magnetic flux vector control of the FR-D700 SC series is the same function as
the FR-E500 series.
Pr. Initial
Name
No. Value
Rated
Electronic ther- inverter
9
mal O/L relay output
current
71
Applied motor
80
Motor capacity 9999
The above parameters can be set when Pr. 160 = 0.
Refer to appendix A for the rated inverter output current.
NOTES If the following conditions are not satisfied, select V/F control since malfunction such as
insufficient torque and uneven rotation may occur.
● The motor capacity should be equal to or one rank lower than the inverter capacity. (The
capacity should be 0.1kW or more.)
● Motor to be used is any of Mitsubishi standard motor (SF-JR, SF-HR 0.2kW or more) or
Mitsubishi constant-torque motor (SF-JRCA four-pole, SF-HRCA 0.2kW to 7.5kW). When
using a motor other than the above (other manufacturer's motor), perform offline auto
tuning without fail.
Single-motor operation (one motor run by one inverter) should be performed.
The wiring length from inverter to motor should be within 30m. Otherwise, the drive beha-
viour may be impaired or the offline auto tuning may be cancelled and an appropriate alarm
issued. Perform offline auto tuning in the state where wiring work is performed when the wir-
ing length exceeds 30m.
Permissible wiring length between inverter and motor differs according to the inverter capac-
ity and setting value of Pr. 72 "PWM frequency selection" (carrier frequency). (Refer to page
3-11).
Control mode
● V/f control and general-purpose magnetic flux vector control are available with the
FR-D700 SC inverters.
● V/f control is for controlling frequency and voltage so that the ratio of frequency (f) to voltage
(V) is constant when changing frequency.
● General-purpose magnetic flux vector control divides the inverter output current into an
excitation current and a torque current by vector calculation, and makes voltage compen-
sation to flow a motor current which meets the load torque.
(General-purpose magnetic flux vector control is the same function as the FR-E500 series.)
FR-D700 SC EC
Setting Range Description
0–500A Set the rated motor current.
By selecting a standard motor or constant
0/1/3/13/23/40/
0 torque motor, thermal characteristic and
43/50/53
motor constants of each motor are set.
0.1–7.5kW Applied motor capacity.
9999 V/f control
Adjust the output torque (current) of the motor
Parameters referred to
19
71
77
178–182
GP MFVC GP MFVC GP MFVC
Refer to
Section
3 Base frequency 6.4.1
Base frequency 6.4.1
voltage
Applied motor 6.7.2
Parameter write 6.16.2
selection
6.9.1
I
nput terminal
function
selection
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