Field-oriented control and direct torque control for a five-phase fault-tolerant flux-switching permanent-magnet motor

Abstract

This paper presents a comparative performance analysis of a new five-phase fault-tolerant flux-switching permanent-magnet(FT-FSPM) motor for high-reliability applications under the two most popular control schemes, namely, field-oriented control(FOC) and direct torque control(DTC) based on stator-flux orientation. Firstly, the new motor topology and structural characteristics are briefly presented. Secondly, the d- and q- axis for the FT-FSPM motor are defined, which is crucial to the mathematical model and control scheme, and the mathematical models are derived. Then, two control schemes, i.e., FOC and DTC, and the main system are proposed. The operational principles of the two control schemes are presented, and space vector pulse width modulation(SVPWM) based on four neighboring vectors is adopted to reduce current harmonics and torque ripples. Finally, the simulated and experimental results are given, and performance analysis of the two control schemes are compared and discussed. The results reveal that FOC scheme has the sinusoidal phase current and low torque ripples, while the DTC scheme has fast dynamic response, verifying the effectiveness of the two proposed control schemes. This paper is a primary investigation for more possible improvements in the control schemes of the five-phase FS-FTPM motor.