Induction motor - calculating rotor flux angle.

[Fasset]

Hello.
I'm trying to write my own soft for Field Oriented Control of induction motor. I have finished 3ph 3kW inverter, controled by STM32F4, and V/F open loop algorithm to control ACIM - it works. Now I'm trying to implement FOC algorithm.
As we know we need to do Clark&Park transformation.
To calculate Park transformation it's necessary to know rotor angle flux position. Here some details:
ftp://ftp.ti.com/pub/dml/DMLrequest/Christy_FTP-10-30-12/controlSUITE/development_kits/HVMotorCtrl+PfcKit_v2.0/HVACI_Sensored/~Docs/Sensored%20FOC%20of%20ACI.pdf

http://ww1.microchip.com/downloads/en/AppNotes/ACIM Vector Control 00908a.pdf

Another note propose to use speed integration to do this:

http://tinyurl.com/y9lrb4cr

Could anyone expalin how to do this exactly?
I'm measuring currents (5kHz sampling), calculate Clark and measuring speed, slip also.
Thanks for any response.

 

[iop95]

If use AN908, equations from page 4 are implemented in routine exemple at page 34.
Maybe need to initialize Imr=Id and use eq. Imr(k)=Id(k) + T/Tr*(Id(k) - Imr(k-1)). For fs and theta use values from same step.