Rotor position measurement for a magnetically levitated 500´000 rpm permanent magnet machine

In this paper, we propose a DSP or FPGA based transversal flux eddy current sensor position measurement technique for rotors in high-speed electrical drives using active magnetic bearings. Compared to the state-of-the-art demodulation technique using analog mixers or rectifiers, the published method shows a lower circuit complexity and allows fulfilling the high bandwidth needs of highly dynamic systems as well as the improved accuracy necessary in precision bearings. Accordingly and also verified by experiments, the concept is well suited to measure the rotor position of a developed ultra-high-speed electrical drive.