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Firmware Stable

D-axis excitation

This subsystem enables d-axis current control for other-than flux weakening purposes. Specifically, MTPA (Maximum Torque Per Ampere) is implemented.

info
  • The following variables are located in the /driver/dac folder.
  • This page is related to the VECTOR algorithm only.

The MTPA, using the motor parameters, is trying to find the best value of the D-axis current to maximize the shaft torque for the given total stator current. This algorithm is suited usually for the IPM motors. The algorithm has to work with many constraints depicted below:

MTPA current and voltage limitations

Parameters​

dxc [.iref]​

This parameter limits the maximum d-axis current for the other-than flux weakening purposes <0:disable>

Previously, this parameter was named mtpa.

mtk [-]​

The MTPA feedback gain. The higher the value, the faster is the MTPA algorithm convergence. The lower the value, the smoother the response and lower the risks of oscillations. <0:direct map>

Special value: 0 - disables the MTPA algorithm and forces dxc * iref current as the D-axis current reference.

States (only esc5)​

idref_dx [A]​

The calculated d-axis excitation current reference.