Vector Control And Real Sensorless Vector Control - Mitsubishi Electric FR-A800 Series Instruction Manual

• When using an IPM motor MM-CF, simply performing the motor parameter initialization (PM parameter initialization or IPM
initialization) enables PM sensorless vector control.
Inverter
Speed
command
Speed/magnetic
pole position
NOTE
• The PM sensorless vector 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-CF 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.
5.2.1

Vector control and Real sensorless vector control

Vector control is one of the control techniques for driving an induction motor. To help explain Vector control, the fundamental
equivalent circuit of an induction motor is shown below.
im
r
In the above diagram, currents flowing in the induction motor can be classified into a current id (excitation current) for making
a magnetic flux in the motor and a current iq (torque current) for causing the motor to develop torque.
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5. PARAMETERS
5.2 Control method
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PM sensorless vector control image
Output
voltage
Inverter
Controller
circuit
Magnetic field observer
*1
Virtual motor
Motor
Mitsubishi Electric IPM motor (MM-CF)
IPM motor (other than MM-CF), SPM motor
1
1
id M
search engine
*1 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.
The offline auto tuning is required.
r1: Primary resistance
r2: Secondary resistance
1: Primary leakage inductance
2: Secondary leakage inductance
2
M: Mutual inductance
S: Slip
r
2
iq
id: Excitation current
S
iq: Torque current
im: Motor current
Condition
page 66.) (When the wiring length from the inverter