Mitsubishi Electric FR-E800 Series Instruction Manual page 92

NOTE
• Real sensorless vector control requires the following conditions.
If these conditions are not satisfied, select V/F control. Otherwise, malfunctions such as insufficient torque, uneven rotation
may occur.
• For the motor capacity, the rated motor current should be equal to or less than the rated inverter current. (Note that the motor
rated current should be 0.4 kW or higher (0.1 kW or higher for the 200 V class).)
If a motor with substantially low rated current compared with the inverter rated current is used, speed and torque accuracies
may deteriorate due to torque ripples, etc. Set the rated motor current to about 40% or higher of the inverter rated current.
• Offline auto tuning is performed.
Offline auto tuning is required under Real sensorless vector control even when the Mitsubishi Electric motor is used since the
wiring length affects the operation.
• Single-motor operation (one motor to one inverter) is performed.
• A surge voltage suppression filter (FR-ASF/FR-BMF) is not used.
 Vector control
• With a vector control option (FR-A8AP E kit) installed, full-scale vector control operation of a motor with an encoder can
be performed. Speed control (zero speed control, servo lock) and torque control can be performed with fast response and
high accuracy.
• Vector control has excellent control characteristic compared to other control methods such as V/F control. Its control
characteristic is equal to those of DC machines.
• This control method is useful for the following purposes:
- To minimize the speed fluctuation even at a severe load fluctuation
- To generate a low speed torque
- To prevent machine from damage due to a too large torque (To set the torque limit)
- To control the torque
- To control a torque generated in a motor in a servo-lock state (the motor with its shaft stopped)
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4. Control Method