Sensorless Control of Dual Three-Phase PMSM based on Sliding Mode Observer Robust to Open-phase Faults

Sensorless control in dual three-phase permanent magnet synchronous motors (DTP-PMSMs) is particularly suitable for high-speed motor control system due to the high reliability and medium-voltage, high-current characteristics. However, open-phase faults (OPFs) in the motor can distort the observed back electromotive forces (EMFs), hindering the accurate estimation of the rotor position. The observed back EMF distortion is induced by the incorrect transmission of the voltage signal in the faulty phase based on the analysis. A sliding mode observer (SMO) is proposed based on dual d-q coordinate transformation to avoid the distortion of the observed EMFs in case of OPFs. The coupling between 2 sets of three-phase windings are also considered in the proposed method. Experimental results show that the method can accurately estimate the rotor position under OPF