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-A700 Series Instruction Manual

3.3.8 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. When higher accuracy and fast response control is necessary, select the real sensorless
vector control and perform offline auto tuning and online auto tuning.
• 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.
• What is real sensorless vector control?
This function enables vector control with a general-purpose motor without encoder. It is suitable for
applications below.
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
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. (note that the capacity is
0.4kW or more)
Motor to be used is either Mitsubishi standard motor, high efficiency motor (SF-JR, SF-HR two-pole, four-pole, six-
·
pole 0.4kW or more) or Mitsubishi constant torque motor (SF-JRCA, SF-HRCA 200V class four-pole 0.4kW to
55kW). 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.)
· When terminal assignment is changed using Pr. 178 to Pr. 189 (input terminal function selection) , other functions may be affected.
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. In addition, do not use a sine wave filter (MT-BSL/BSC).
· Do not perform real sensorless vector control with a surge voltage suppression filter (FR-ASF-H) or sine wave filer (MT-BSL/
BSC) connected.
Initial
Setting Range
Value
0 to 8, 13 to 18, 20,
0 23, 24, 30, 33, 34, 40, 43,
44, 50, 53, 54
55K or less 0.4 to 55kW
9999 75K or more 0 to 3600kW
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
control
*
V/F control
Vector control (Refer to page 58)
Vector control test operation
Speed control
Torque control
MC signal-ON:torque
MC signal-OFF:speed
V/F control (advanced magnetic flux vector
control)
Instruction Manual (applied)).
Set 10 + number of
motor poles.
Real sensorless
vector control
*
55
3