"M1 MCAT Control" variable too. Use "M1 Application Switch" variable to turn on or off the application. Set/clear "M1 Application
Switch" variable also enables/disables all PWM channels.
The scalar control diagram is shown in
. It is the simplest type of motor-control techniques. The ratio between the
magnitude of the stator voltage and the frequency must be kept at the nominal value. Hence, the control method is sometimes
called Volt per Hertz (or V/Hz). The position estimation BEMF observer and tracking observer algorithms (see Sensorless
PMSM Field-Oriented Control (
) for more information) run in the background, even if the estimated position
information is not directly used. This is useful for the BEMF observer tuning.
Figure 15. Scalar control mode
The block diagram of the voltage FOC is in
. Unlike the scalar control, the position feedback is closed using the BEMF
observer and the stator voltage magnitude is not dependent on the motor speed. Both the d-axis and q-axis stator voltages can be
specified in the “M1 MCAT Ud Required” and “M1 MCAT Uq Required” fields. This control method is useful for the BEMF observer
functionality check.
Figure 16. Voltage FOC control mode
The current FOC (or torque) control requires the rotor position feedback and the currents transformed into a d-q reference frame.
There are two reference variables (“M1 MCAT Id Required” and “M1 MCAT Iq Required”) available for the motor control, as shown
in the block diagram in
. The d-axis current component "M1 MCAT Id Required" is responsible for the rotor flux control.
The q-axis current component of the current "M1 MCAT Iq Required" generates torque and, by its application, the motor starts
running. By changing the polarity of the current "M1 MCAT Iq Required", the motor changes the direction of rotation. Supposing
that the BEMF observer is tuned correctly, the current PI controllers can be tuned using the current FOC control structure.
NXP Semiconductors
Remote control using FreeMASTER
MCUXpresso SDK Field-Oriented Control (FOC) of 3-Phase PMSM and BLDC motors, Rev. 0, 01/2022
User Guide
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