Abstract
This paper presents a five-phase fault-tolerant permanent-magnet synchronous machine (PMSM) used for electric vehicles. In multiphase fault-tolerant PMSMs equipped with fractional-slot concentrated windings, excessive magneto-motive force (MMF) harmonics can lead to thermal demagnetization of the permanent magnets (PMs). In order to reduce the lower-order harmonics, the origins of the 2-pole harmonic in conventional winding configurations are investigated, and an unequal-turn winding configuration is applied to cancel the lower-order harmonics. The main electromagnetic performances of the unequal-turn winding configuration are investigated and compared with conventional winding topologies. Based on the principle of maintaining constant instantaneous power, the fault-tolerant control strategies for open-circuits of up to two phases are developed. All of the investigations are verified by finite element analysis (FEA) results.
Highlights
High fault-tolerant capability and high reliability are increasingly required in various applications.Owing to its high power density and high efficiency, a multiphase fault-tolerant permanent-magnet synchronous machine (PMSM) is often considered an excellent candidate for safety critical applicationsEnergies 2014, 7 such as electric vehicles (EVs), marine propulsion and aerospace
In order to minimize the effect of fault phases on the other healthy phases, multiphase fault-tolerant PMSMs are designed to have low mutual inductances between different phases, and each phase of the machine is driven by a separate Hbridge converter
PMSMs equipped with fractional-slot concentrated windings (FSCWs) have increasingly been used in EV applications [1,2,3,4,5,6,7]
Summary
High fault-tolerant capability and high reliability are increasingly required in various applications. A five-phase in-wheel outer-rotor PMSM which shows advantages in high fault-tolerant ability and low torque ripple is proposed for high-reliability four-wheel-drive EVs. And the investigated multiphase PMSM adopts FSCW to obtain satisfactory fault-tolerant performance and low torque ripple, and these features make the machine quite competitive for four-wheel-drive EVs. For PMSMs equipped with FSCWs, the MMF harmonics cause eddy currents in PMs, and this leads to a temperature rise. Based on the principle of maintaining constant instantaneous power, the phase currents for healthy phase windings are obtained by minimizing a cost function of copper loss Under this scheme, the five-phase PMSM enables continuous and smooth operation with open-circuit faults of up to two phases. Double-layer winding features advantages in rotor losses and mechanical balancing [15,16], combining the high-efficiency requirement of EV applications, the 20-slot/22-pole double-layer winding configuration is further investigated in this paper. In following section we focus on the investigation of the 2-pole sub harmonic
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
