Driving an ACIM (AC induction machine)

The induction motor is outside the primary focus of our customers. Nevertheless, our driver is well suited for this type of motor. There are two supported methods:

• U/f mode. This is the simple, widely recognized control method, commonly referred to as "variable frequency drive" for induction motors. The frequency is coupled to the output voltage. This method is easy to configure, offers a stable operation, but only the voltage mode is supported. Current control / torque control is provided indirectly, through imult command / iref parameter.

• FOC mode. Employs the full FOC with axes separation, working with the slip angle and enabling more precise control. With this type, the induction motor achieves most of the drive modes we normally introduce for a PMSM.

How to configure

tip

We recommend consulting our technical support team for assistance with this type of motor.

• set /driver/psi to 0 (no flux linkage in the squirrel cage)
• set /driver/dac/mtk to $0$ (disengage MTPA algorithm)

For U/F mode

• set /driver/dac/dxc to $0.707$ ($\sqrt{2}/2$) set direct axis current limit to match the quadrature axis current limit)
• set /driver/vcf to $12$ (disable current control in direct axis, choosing VFD mode)
• set /driver/prest to $0$ (asynchronous mode - decouple the field angle from the rotor)
• set /driver/rest/omega to the desired ratio between the voltage and the frequency. Please contact siliXcon to get this value for your motor.

For FOC mode

• set /driver/dac/dxc to the desired flux current. Please contact siliXcon to get this value for your motor.
• set /driver/prest to the value representing your motor sensor (usually, a quadrature encoder).
• set /driver/rest/omega to the desired slip angle dependence to the stator current. Please contact siliXcon to get this value for your motor.

Limitations

• Do not use identrun and identlin commands.
• Please use only VECTOR algorithm. BLDC has no use for this type of motor.
• For the ACIM in FOC mode, sensorless mode is not supported at the moment. You need to provide a shaft sensor.