Robobo
Vector Park Transform

Detailed Description

Forward Park transform converts the input two-coordinate vector to flux and torque components. The Park transform can be used to realize the transformation of the Ialpha and the Ibeta currents from the stationary to the moving reference frame and control the spatial relationship between the stator vector current and rotor flux vector. If we consider the d axis aligned with the rotor flux, the diagram below shows the current vector and the relationship from the two reference frames:

park.gif
Stator current space vector and its component in (a,b) and in the d,q rotating reference frame

The function operates on a single sample of data and each call to the function returns the processed output. The library provides separate functions for Q31 and floating-point data types.

Algorithm
parkFormula.gif
where Ialpha and Ibeta are the stator vector components, pId and pIq are rotor vector components and cosVal and sinVal are the cosine and sine values of theta (rotor flux position).
Fixed-Point Behavior
Care must be taken when using the Q31 version of the Park transform. In particular, the overflow and saturation behavior of the accumulator used must be considered. Refer to the function specific documentation below for usage guidelines.