# D-axis excitation

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

- Next variables are located in the folder
.`/driver/dac`

- This page is related to the
**VECTOR**algorithm only.

The MTPA, using the motor parameters, is trying to find best value of the D-axis curernt to maximize the shaft torque for the given total stator current. This algorithm is suited usually for the IPM motors.

### Parameters

`dxc`

[.iref]

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

`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 oscilations. <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.