2.1.3 Inverse Park Transformation

The Inverse Park Transformation transforms electrical signals from the rotating two-axis orthogonal reference frame (dq) to the two-axis orthogonal stationary reference frame (ɑβ) as shown in the following figure.

The transform is expressed by the following equations:

${\displaystyle u_{\alpha }=U_d\cos \left({\theta }_e\right)-U_q\sin \left({\theta }_e\right)}$

${\displaystyle u_{\beta }=U_d\sin \left({\theta }_e\right)+U_q\cos \left({\theta }_e\right)}$

Where:

U_d and U_q are voltages in the two-axis orthogonal dq rotating reference frame, and U_α and U_β are voltages in the two-axis orthogonal αβ reference frame.