5-144
5-11 Sensorless Vector Control
SYSDRIVE MX2 Series USER'S MANUAL (3G3MX2-Axxxx)
5
Functions
5-11 Sensorless Vector Control
The following explains the sensorless vector control, which is based on estimation of the motor
rpm and output torque from the motor parameter settings.
Sensorless vector control cannot be selected for High-frequency Induction Motor (b171 = 02)
and Light Load Mode (b049 = 01).
Sensorless Vector Control
In this method, the motor rpm and output torque are controlled by estimating these parameters
based on the Inverter's output voltage and current, as well as the motor parameter settings.
High starting torque can be generated to enable high-accuracy operation, even in a low-
frequency range (0.5 Hz).
When this function is used, set Control Method (A044/A244) to "03: Sensorless vector control."
When this function is used, make sure to refer to "Motor Parameter Selection" on page 5-145
and that the settings are optimum for the motor used.
 Sufficient characteristics may not be obtained if you select a motor size two or more ranks lower
than the maximum applicable motor.
 The speed may increase at low frequencies (several hertz).
 When the Inverter incoming voltage is higher than the rated voltage of the drive motor, current may
increase and normal operation may not be performed if "01: Always OFF" or "02: OFF during
deceleration" is selected for AVR Selection (A081/A281). In this case, change AVR Selection to
"00: Always ON."
Parameter
No.
Function name Data
Default
setting
Unit
A044/A244
Control Method
1/2
03: Sensorless vector control (SLV) 00 −