Fractional-slot Concentrated-winding PM Research Articles

Study on Outer Rotor FSCW Permanent Magnet Machines for Unmanned Aerial Vehicle Electric Green Taxiing Systems

This paper considers the possibility of adopting an outer rotor fractional slot concentrated winding (FSCW) permanent magnet synchronous machine (PMSM) for Unmanned Aerial Vehicle Electric Green Taxiing (EGT) application. The electromagnet performance such as no-load air-gap flux density, flux linkage distribution, electromotive force (EMF), average torque, torque ripple, and iron losses are studied by finite-element analysis (FEA). The results show the iron loss is mainly effected by the machine frequency. The unmanned aerial vehicle EGT structure are introduced, which includes the outer rotor FSCW PM machine, the reducer, the clutch, and the tire.

Analysis of Air-Gap Field Modulation and Magnetic Gearing Effect in Fractional-Slot Concentrated-Winding Permanent-Magnet Synchronous Machines

In this paper, the torque production of fractional-slot concentrated-winding (FSCW) permanent-magnet synchronous machines (PMSMs) is analyzed from the perspective of the air-gap field harmonics modulation accounting for slotting effect. It is found that the average torque of FSCW PMSM is produced by both the principle of conventional PMSM and the magnetic gearing effect. A finite-element analysis (FEA) based equivalent current sheet model and harmonic restoration method is first used in FSCW PM machines with different slot–pole number combinations to quantify the respective contribution of the conventional PMSM and the magnetic gearing effect to the average torque. The influence of slot opening on the magnetic gearing effect, cogging torque, and torque ripple is analyzed. The results show that the magnetic gearing effect makes a nonignorable contribution to the average torque when a large slot opening stator is used. The expression of the gear ratio in FSCW PMSMs is derived. The influence of gear ratio on the contribution of the magnetic gearing effect to the total torque is investigated by FEA. The FEA-predicted torques are validated by experiments on the prototypes.

Performance Analysis of Novel Fractional-Slot Concentrated-Winding Permanent Magnet Machine with Different Pole and Slot Matching

In order to analyze the possibility of the fractional-slot concentrated-winding for wind generation, this paper states the merits of fractional-slot concentrated-winding permanent magnet machines, and then analyzes the electromagnetic design rules of fractional-slot concentrated-winding. The fractional-slot concentrated-winding permanent magnet machine is modeled and designed in electromagnetic, and its performance is analyzed, some conclusions can be obtained, which will provide reference for further analysis and application of fractional-slot concentrated-winding PM machine.

Design and Analysis of Fractional-Slot Concentrated-Winding Permanent Magnet Machine for Wind Power Generation

In order to obtain the low synchronous speed, fractional-slot concentrated-winding PM machine is adopted to wind power generation system. This paper analyzed the pole slot combination rule, and then studied the electromagnetic design method by taking 12-slot and 10-pole machine. By using the finite element software, the characteristics is analyzed for this fractional-slot concentrated-winding permanent magnet generator, the research results show that this generator has good performance, thus prove that fractional-slot concentrated-winding scheme is feasible and effective.