Flux position estimation method of IPMSM by controlling current derivative at zero voltage vector

There are many methods identifying flux position of Interior Permanent Magnet Synchronous Motor (IPMSM) without mechanical sensors. The method which uses both the back EMF and the saliency to identify flux position of IPMSM without high frequency components injection at low speed has been reported. It was extended in order to drive with no load to light load. The authors propose the method of combining those methods with the different PI controllers for dI_dest/dt dI_quest/dt. We also introduce compensation values F_L and F_H in order to reduce position error while the estimation rule is under selecting.