Large Starting Torque And Low Speed Torque Are Necessary (Advanced Magnetic Flux Vector Control, Real Sensorless Vector Control) (Pr. 71, Pr. 80, Pr. 81, Pr. 800) - Mitsubishi Electric FR-A701 Instrucion Manual

4.3.8 Large starting torque and low speed torque are necessary (advanced magnetic
flux vector control, real sensorless vector control) (Pr. 71, Pr. 80, Pr. 81, Pr. 800)
Magnetic flux Magnetic flux Magnetic flux Sensorless Sensorless Sensorless
Advanced magnetic flux vector control can be selected by setting the capacity, poles and type of the motor used in Pr.
80 and Pr. 81. Real sensorless vector control can be selected for applications requiring high accuracy and fast response
control. Perform offline auto tuning and online auto tuning when using real sensorless vector control.
• What is advanced magnetic flux vector control?
The low speed torque can be improved by providing voltage compensation so that the motor current which meets the
load torque to flow. Output frequency compensation (slip compensation) is made so that the motor actual speed
approximates a speed command value. Effective when load fluctuates drastically, etc.
Low-speed torque is improved as compared to V/F control. In addition, speed accuracy is improved when load is
applied.
• What is real sensorless vector control?
This function enables vector control with a general-purpose motor without encoder. Low speed torque and speed
accuracy are improved as compared to advanced magnetic flux vector control. Always perform offline auto tuning
and online auto tuning when using real sensorless vector control.
Real sensorless vector control is suitable for the following applications.
· To minimize the speed fluctuation even at a severe load fluctuation
· To generate low speed torque
· To prevent machine from damage due to too large torque (torque limit)
· To perform torque control
Parameter
Name
Number
71 Applied motor
80 Motor capacity
81 Number of motor poles
800 Control method selection
* Use Pr. 178 to Pr. 189 to assign the terminals used for the X18 and MC signal. (Refer to chapter 4 of
POINT
If the following conditions are not satisfied, select V/F control since malfunction such as insufficient torque and uneven
rotation may occurr.
· The motor capacity should be equal to or one rank lower than the inverter capacity.
· Motor to be used is either Mitsubishi standard motor, high efficiency motor (SF-JR, SF-HR two-pole, four-pole, six-pole
3.7kW or more) or Mitsubishi constant torque motor (SF-JRCA four-pole, SF-HRCA 3.7kW or more). When using a
motor other than the above (other manufacturer's motor), perform offline auto tuning without fail. (advanced magnetic
flux vector control)
When performing real sensorless vector control, offline auto tuning are necessary even when Mitsubishi motor is used.
· Single-motor operation (one motor run by one inverter) should be performed.
· The wiring length from inverter to motor should be within 30m. (Perform offline auto tuning in the state where actual
wiring work is performed when the wiring length exceeds 30m.)
CAUTION
· Uneven rotation slightly increases as compared to the V/F control. (It is not suitable for machines such as grinding machine and
wrapping machine which requires less uneven rotation at low speed.)
· Changing the terminal assignment using Pr. 178 to Pr. 189 (input terminal function selection) may affect the other functions.
Please make setting after confirming the function of each terminal.
· When advanced magnetic flux vector control is performed with a surge voltage suppression filter (FR-ASF-H) connected,
output torque may decrease.
· Do not perform real sensorless vector control with a surge voltage suppression filter (FR-ASF-H) connected.
Initial
Setting Range
Value
0 to 8, 13 to 18, 30, 33, 34,
0
40, 43, 44, 50, 53, 54
0.4 to 55kW
9999
9999
2, 4, 6, 8, 10
9999 12, 14, 16, 18, 20
9999
0 to 5
9
10
11
20
12
20
Before operation
Description
By selecting a standard motor or constant
torque motor, thermal characteristic and
motor constants of each motor are set.
Set the applied motor capacity.
V/F control
Set the number of motor poles.
X18 signal-ON:V/F Set 10 + number of
control motor poles.
*
V/F control
Vector control (Refer to page 66)
Vector control test operation
Speed control
Torque control Real sensorless
vector control
MC signal-ON:torque
MC signal-OFF:speed
*
V/F control (advanced magnetic flux vector
control)
the instruction manual (applied).)
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