Hello. I'm trying to write my own soft for Field Oriented Control of induction motor. I have finished hardware - 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 also measure speed, slip. Thanks for any response.