Rotor position measuring method for magnetic levitation high speed PMSM based on fuzzy sliding mode observer

Focused on the chattering problem of the sliding mode observer (SMO) when the motor speed is low, this paper proposes a kind of magnetic levitation high speed PMSM (HSPMSM) rotor position measuring method based on fuzzy SMO. This method can suppress the chattering problem of the SMO which used the fuzzy control system to change the gain of the SMO. It is more powerful than the SMO based on saturation function which is analysed in theory. In this paper, simulation and experiment with a 4 kW magnetic levitation high speed permanent magnet synchronous motor are carried out and the position estimation error is analyzed and a compensation method is proposed. The results demonstrate that the fuzzy SMO can effectively estimate the magnetic levitation high speed PMSM rotor position in a wide speed range.