Phase-Shifting Fault-Tolerant Control of Permanent-Magnet Linear Motors with Single Phase Current Sensor

In this paper, a phase-shifting fault-tolerant control (PS-FTC) with single phase current sensor is proposed for primary permanent-magnet linear motor (PPMLM) traction system. The phase with healthy sensor is defined as the first phase while the other two phases without healthy sensors are respectively defined as the second and third phases. In PS-FTC, hysteresis current control (HCC) is adopted. The actual currents of the second and third phases are replaced by the estimated values while the reference values are obtained by phase-shifting of the estimated first phase current. Although the linear motor parameters have been used in the calculation of the estimated currents, the parameter variations do not affect the performances of PS-FTC. Compared with existing schemes with single phase current sensor, PS-FTC is robust and shows better steady-state performances. The effectiveness of PS-FTC is verified by theoretical analysis and experimental results.