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Test operation and gain adjustment of the PM sensorless vector control
4
PARAMETERS
4.3 Test operation and gain adjustment of the PM sensorless
vector control
4.3.1 Outline of the PM sensorless vector control
A dedicated S-PM (magnet) motor is a highly efficient motor compared to an induction motor. With this S-PM motor, highly
efficient motor control and highly accurate motor speed control can be performed.
The motor speed is detected by the output voltage and current of the drive unit. It does not require a speed detector such as
an encoder.
4.3.2 PM motor test operation (Pr. 800)
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 144)
(1) Test operation
Setting Pr. 800 Control method selection = "9" will enable the PM motor test operation.
Perform a test operation by giving a speed and a start command under each of PU/External/Network operation mode.
Purpose Parameter that must be Set Refer to Page
To perform PM motor test Control method selection Pr. 800
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To adjust the gain for PM motor control Adjusting the speed control gain Pr. 820, Pr. 821
71
POINT
The following conditions must be met to perform PM sensorless vector control.
· For the motor model, dedicated S-PM motor must be used.
·
A specified combination of the motor capacity and the drive unit capacity must be used.
· Single-motor operation (one motor run by one drive unit) must be performed.
· The overall wiring length with the motor must be 30m or less.
NOTE
y Constant-speed operation cannot be performed in the low-speed range lower than 300r/min. Generally, speed control
can be performed in the range that satisfies the ratio, 1:10. (Adjustable with Pr. 785.)
y The RUN signal is output about 100ms after turning ON the start command (STF, STR). The delay is due to the
magnetic pole detection.
Without connecting an PM motor, the speed movement can be checked by the monitor or analog signal output.
Two types of operation can be selected using this parameter: an actual operation by connecting an PM motor,
or a test operation without connecting an PM motor to simulate a virtual operation.
Parameter
Number
Name
Initial
value
Setting
range
Operation
800
Control method
selection
30
9
PM motor test operation (Motor is not driven even if it
is connected.)
30 Normal operation (Motor can be driven.)
REMARKS
· In the test operation, current is not detected and voltage is not output. Related monitor displays of the output current and
voltage show "0."
PM sensorless vector control image
Inverter
circuit
Controller
Output
current
Ooutput
voltage
Drive unit
Virtual motor
Magnetic field observer
Speed
command
∗
Speed/magnetic
pole position
* A magnetic field observer is a control
method that calculates the motor
speed/magnetic pole position based
on the motor voltage and current of a
virtual motor which is set up in the
drive unit.
Time
Running speed
(FM output)
STF
RUN
