Mitsubishi Electric FR-F800 Series Instruction Manual page 177

 PM motor control
• The inverter enables highly efficient motor control and highly accurate motor speed control of a PM (permanent magnet
embedded) motor, which is more efficient than an induction motor.
• A speed detector such as an encoder is not required as the inverter estimates the motor speed by the calculation from the
inverter output voltage and current. The inverter drives the PM motor with the least required current for a load in order to
achieve the highest motor efficiency.
• When using an IPM motor MM-EFS or MM-THE4, simply performing the motor parameter initialization (PM parameter
initialization or IPM initialization) enables PM motor control.
Inverter
Speed
command
Speed/magnetic
pole position
NOTE
• The PM motor control requires the following conditions.
• The motor described in the following table is used.
• For the motor capacity, the rated motor current should be equal to or less than the rated inverter current. (It must be 0.4 kW
or higher.)
If a motor with substantially low rated current compared with the inverter rated current, however, 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.
• Single-motor operation (one motor to one inverter) is performed.
• The wiring length from the inverter to the motor is 100 m or less. (Refer to
to the IPM motor MM-EFS or MM-THE4 exceeds 30 m, perform offline auto tuning.)
• A surge voltage suppression filter (FR-ASF/FR-BMF) or sine wave filter (MT-BSL/BSC) is not used.
176
5. PARAMETERS
5.2 Control method
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PM motor control image
Output
voltage
Controller
Magnetic field observer
Virtual motor
Motor
Mitsubishi Electric IPM motor (MM-EFS or MM-THE4)
IPM motor (other than MM-EFS or MM-THE4), SPM motor The offline auto tuning is required.
search engine
Inverter
circuit

 A magnetic field observer is a control
Output
method that calculates the motor
current
speed/magnetic pole position based
on the motor voltage and current of a
virtual motor which is set up in the
drive unit.
The offline auto tuning is not required.
Condition
page 57.) (When the wiring length from the inverter