부산대학교 도서관

To enhance system position estimation reliability when a single-phase open-circuit fault occurs, this study provides a sensorless control strategy based on a medium and high-speed super-twisting sliding mode observer (ST-SMO) for a five-phase permanent magnet synchronous motor, in which the space vector pulse width modulation (SVPWM) control strategy is adopted. In this method, a super-twisting sliding mode observer is developed to achieve any two-healthy phase back electromotive force (EMFs) estimation, during normal and open-circuit fault operations, irrespective of parameter variations and external disturbances. Then a phase-locked loop (PLL) is presented to extract the position and the speed of the rotor directly from the estimated two phase back-EMFs. The proposed ST-SMO algorithm achieves strong robustness to various external variations, suppresses system chattering, and enhances the estimation accuracy in the medium and high-speed range. Simulation and experimental results are provided to verify the effectiveness of the proposed method under different load conditions over medium to high-speed ranges.