The present study deals with sensorless fault-tolerant control (SFTC) of five-phase Interior Permanent Magnet Synchronous Motors (IPMSMs). First, a Proportional-Integral Model Reference
Adaptive System (PI-MRAS) speed estimator is proposed. The MRAS compares outputs of reference and adaptive models. Then, PI controller is utilized to generate the estimated speed by
minimizing current errors between the two models. Second, a novel Sign Integral Terminal Sliding Mode Controller (SITSMC) is suggested in the presence of open phase faults. The proposed
controller tolerates these faults through a transformation matrix tuning technique in view of
equal current and minimum copper loss schemes. Meanwhile, SITSM controller utilizes the estimated speed of PI-MRAS block. Third, stability of the closed-loop system is provided by Lyapunov
theorem. Finally, simulation results validate the feasibility and effectiveness of the suggested
SFTC strategy both in normal and open one phase faulty conditions for a five-phase IPMSM.